Episode 8

The outskirts of Cardiff, 2.07 p.m.

Squeezed into the rear seat of Andy's squad car between two bemused women, the Doctor closed Dave's laptop and handed it back to him with a wink.

'Very impressive,' he said in a loud voice.

The car was going 'blues and twos', tearing its way along Cowbridge Road towards the castle. Occasionally other drivers sounded their horns as Andy shot through the tiniest gaps in the traffic.

'And I'm not easily impressed, as a rule. Fair play to you, Dave. Project Précis – Print Recognition, Electronic Compression, and Information Storage. It does exactly what it says on the tin. In fact, it's a brilliant idea.'

'Diolch yn fawr,' Dave replied with a smile, somewhat surprised.

He'd only known the Doctor for a short time, but he'd soon been struck by the other man's sharp intelligence. When the Doctor had asked to look at Dave's blueprints, he'd agreed immediately, sensing that this mysterious man would find any flaws in his design in seconds. He'd been expecting his invention to come in for a barrage of criticism, instead of such lavish praise. True to form, the Doctor didn't disappoint him when he spoke again.

'Yes, it is a truly brilliant invention.' He sat back and stroked his chin. 'Of course, my people developed this technology ages ago. It did exactly the same thing. We dumped it because it didn't work.'

'It works perfectly.' Dave's smile vanished as quickly as Pam's Metro had earlier on.

'Yeah – technically, it's spot-on. But have you thought about the effects it'll have on society?'

Dave shook his head.

'Sorry, I'm not with you.'

By way of answer, the Doctor belted out the opening bars of the 'Hallelujah Chorus'. Pam tried not to laugh, and Andy resisted the temptation to join in. The Doctor stopped singing and faced Dave again.

'Now, imagine scanning the score of Handel's Messiah into your machine. The software analyses it, decides that the content is too repetitive, and erases all but the first "Hallelujah" because it thinks they're redundant. Or what about a bit of the Bard?' He struck a pose and declaimed, '"Tomorrow, and tomorrow, and tomorrow, creeps in this petty pace from day to day ..."' He frowned and looked straight into Dave's eyes. 'Error report: suggest deleting repeated words. Then again, if you want to really fuck things up, try feeding in some James Joyce or Samuel Beckett, and see what your software makes of them.'

He placed a reassuring hand on Dave's shoulder.

'Look, I've got a Reader's Ticket for the biggest library in the universe, and everything there is still printed on paper. People like books. They look nice, they feel nice, they smell nice, and you don't need any fancy equipment to use them. But with your invention, I only have to push a button and masterpieces of human civilisation vanish into the Odd Sock Vortex.'

'The Odd Sock Vortex?' Pam echoed.

'Yeah, you know. Like when you put a dozen pairs of socks in the washing machine, and when the cycle's finished, there are only twenty-three socks inside. Where does the other one go?'

'I always that was the Borrowers.'

Andy grinned as he shot through the traffic lights, threw the car across the junction and headed down St Mary Street.

'Oh, now you're being silly!' He pulled a face and pressed on. 'The thing is, there are little baby universes opening and closing all the time, like tiny transient bubbles in the fabric of reality. Stuff comes and goes every so often. I think you've come up with a way of creating baby universes on demand, and that's where the hard copies go.'

'Hang on, though – whatever's happened isn't a baby universe,' Karen objected. 'It's something different.'

'Yes, I know.' He gave Dave a meaningful look. 'The problem is, some bright spark not a million miles away from here—' He nodded in Dave's direction '—decided to build a baby universe machine on top of a rift in Space and Time. A hole in the fabric of reality. A bit of a dodgy combination, all in all.'

Everyone in the car was silent for a few moments. Andy had experienced some of the Rift's effects for himself. The others remembered the strange phenomena that had cropped up in the newspapers over the past couple of years. Most people in Cardiff had had a taste of what the Rift could do.

'That's not the only problem,' Pam piped up. 'Some other bright spark went and parked his spaceship on top of that same rift.'

The Doctor looked slightly guilty.

'You've got a spaceship?' Karen looked incredulous.

'Well, strictly speaking it's a space and time machine, but – yes, I've got a spaceship. And yes, I have to confess that I might have been partly responsible for all this.'

Dave glared at him as the implications of his revelation sank in.

'Partly?' Dave repeated. 'Only partly?'

The Doctor grinned back.

'I dunno. Six of one, half a dozen of the other?”

'From what you've just told us, it seems to me that you're almost entirely responsible, Doctor.'

He shrugged.

'Well, maybe ninety per cent.'

Dave's eyes continued to bore into him.

'I'll compromise on fifty-fifty. Tell you what – why don't we split the difference?'

Pam decided to change the subject, and nudged the Doctor sharply in the ribs.

'How many blokes do you know with twelve pairs of socks?'

'I bet Ianto has.'

'Yeah, you're probably right,' she chuckled.

The radio crackled, and Andy listened for a moment before acknowledging the message. He caught the Doctor's eye in the rear-view mirror.

'That was Gwen. They're waiting for us on site – and they've got company.'

He swung the car into Callaghan Square and headed towards the docks.

The Port of Cardiff, 2.21 p.m.

The humming noise from the warehouse had become so loud that everyone had been forced to evacuate the area. Even from two hundred metres away, it was about as loud as a rock concert. Golden light flooded from the windows and bathed the surrounding buildings in its unearthly glow.

The entire port facility was cordoned off with police tape. Kathy Swanson and Vince Price were standing guard just outside the gates, with a handful of uniformed officers nearby. Three green army trucks and a number of jeeps were parked near the fence, and soldiers were milling around in the car park. Jack, Gwen, Ianto and Martha were leaning up against their SUV when Andy's car shot into view and drew up a few inches from the bumper. His passengers got out with relieved expressions on their faces, and the Doctor performed the introductions as usual.

'Was it my imagination, or did we achieve light speed coming around Culverhouse Cross?' Karen gave Andy a dig in the kidneys.

'Don't be daft,' the Doctor said. 'If we could do that, we could just turn back time and stop this from ever happening.' He gave Jack and Martha a meaningful look. 'And as any fool knows, that's completely impossible.'

Martha winked at him and turned to a young fair-haired soldier wearing a red-trimmed cap.

'Doctor, this is Major Chapman. Major, this is the Doctor.'

Chapman shot to attention.

'It's an honour, sir, I've heard all about you.'

The Doctor groaned.

'Please don't salute, I'm not good with authority figures.'

Instead they shook hands warmly. He introduced Dave to the young officer, and explained the professor's involvement in the proceedings. Chapman beckoned Jack over and led the three men towards the police line. As they walked, each man took the opportunity to update the others on developments.

It seemed that the effect had just reached Swansea. Torchwood's own equipment had been taking regular measurements and the phenomenon appeared to be gaining strength. An hour into the crisis, UNIT had been called in and given full powers to act in order to prevent the situation from worsening. The only problem was that nobody had the faintest idea what action to take.

'Well, I'm here now,' the Doctor reassured the harrassed officer. 'I'm sure I'll think of something.'

He nodded polite greetings to Kathy Swanson and Vince Price as they came to the gates. Price glowered at him by way of answer. The police had obviously been cut out of the loop, and he wasn't happy about it. Dave caught sight of Julie Jones and Mohammed Khan sitting in a police car a few metres away, and he waved at them. Julie raised her hands to give him a half-hearted wave, and a glint of silver caught the Doctor's keen eye.

'Why is she wearing handcuffs?' he demanded, turning to Price.

The diminutive policeman strode up to him and looked up into his face, trying to exert what little authority he still had.

'Everyone in that warehouse has been arrested pending further investigations,' he announced.

'Well, in that case you can un-arrest them ASAP!'

Price took an involuntary step backwards as the Doctor loomed over him, his eyes blazing.

'We're going to need all the help we can get.'

He ducked under the tape and walked slowly towards the warehouse, with the others following a few paces behind. All eyes were on them as they walked towards the glowing building. They didn't get far before they were forced back by the deafening noise emanating from within. They retreated to the gates again, shaking their heads in a vain attempt to rid themselves of the after-effects of the sound. Ianto ran to the cordon and slung what appeared to be a set of headphones over the fence. Jack caught it neatly, grinned, and clamped it over his ears.

'Ear protection! That boy thinks of everything!' he bellowed into the Doctor's ear.

Ianto threw another set of modified ear defenders to the Doctor, and two more sets to Dave and Major Chapman. As soon as they were wearing the safety kit, they found themselves in near-silence. Jack gestured to the others to follow him towards the warehouse. To the Doctor's amazement, Martha's voice rang in his ears.

'You're not the only one with tricks up his sleeve, mate.'

'We developed these a few years ago,” Ianto's voice added. “They've got built-in comms on a secure channel. You can talk to each other, we can hear you, and you can hear us.'

'Fantastic!' The Doctor turned and gave Jack's colleagues a wave.

Gwen waved back and her anxious voice came through the tiny speakers.

'Take care, guys.'

'I always do,' Jack retorted in an ironic tone. He pointed at the Doctor. 'It's this bloke who gets me into trouble every time.'

The Doctor raised his middle finger and Jack laughed. He put a hand on Dave's shoulder.

'Professor Dave Probert, this is your big moment.' He grinned. 'Take me to your Reader.'

The four men advanced to the warehouse and the Doctor tried the door. To his surprise it swung open immediately. He turned to Dave and raised his eyebrows.

'Tell your friends they should have locked it up after them,' he teased. 'Anyone could have just walked in here.'

Dave chuckled and followed him into the building, with Jack and Chapman bringing up the rear. The Doctor squinted into the dazzling glow flooding from Dave's machine and walked towards the stairs.

'Blimey, it's bright in here! Ianto, I don't suppose you've brought any sunglasses.'

'They've never really suited me,' came the disembodied reply. 'I always look like I'm in the CIA whenever I wear them.'

'Where's all this light coming from?'

Dave was shielding his eyes with his hand. Chapman was staring, open-mouthed, at the glowing mass in the middle of the empty warehouse. Jack sprinted past the Doctor, sat down at the nearest workstation, inserted a flash drive into the USB port, and started typing rapidly.

'That's pure energy from the Space-Time Vortex, funnelling through the Rift.'

He took a few strides towards the machine and shoved his sonic screwdriver into a gap on its side.

'It's amplifying the effect of your machine, and radiating it out from here so that it's processing every piece of paper in its path,” Jack added, looking at the results flashing up on his monitor.

'Oh my God.' Dave was awestruck by the realisation of what was happening.

'Still, at least it's only one specific frequency.' He looked relieved. 'If it was the full spectrum, most of South Wales would have been swallowed by now.'

'How do we stop it?' Chapman's voice was querulous.

'Your guess is as good as mine,' Dave sighed.

'What's the power source?'

'It draws its energy from hydrogen fuel cells.'

Julie's voice came over the airwaves, and the Doctor's face fell.

'Oh, great!' Jack groaned. 'It'll be around for fucking years.'

'They said that about Laserdiscs,' Ianto quipped.

'Can you reverse the polarity of the neutron flow?' Martha suggested.

'Reverse the polarity of the neutron flow?' the Doctor echoed sarcastically. 'Martha, it's 2009, not the 1970s!'

'There is one thing we could try.'

Jack's firm tone suggested that he'd already come up with a definitive plan of action. He strode to the Doctor's side and tapped the Vortex Manipulator that never left his wrist.

'Could this be modified to increase its teleport catchment area?'

'Yeah, I imagine so.'

Their eyes met and they were silent for a few moments.

Are you thinking what I think you're thinking?' Jack nodded earnestly. 'Okay, let's do it!'

He pulled his sonic screwdriver from the machine and waved it over Jack's wrist.

'A little bit of that old Time Lord jiggery-pokery …'

The bright blue glow from the tool was a tiny glimmer amongst the golden light that surrounded them. Dave and Chapman looked on, completely lost. Jack gestured towards the doorway with his free hand.

'You two, get clear!' Jack shouted.

Without needing any further encouragement, they turned and sprinted from the building.

'Gwen, Martha, tell everyone to get as far away as possible. Major, can I scrounge some high explosives from your boys?'

'How much do you need?' He sounded surprised.

'As much as it'll take to blow this thing to Hell!'

The Doctor put his sonic screwdriver back in his pocket and looked into Jack's eyes. The other man winked at him, ignoring Gwen's and Ianto's frantic objections coming over the comms.

'I'll be okay. Trust me,' he said quietly.

'That's meant to be my line. I'm the bloody doctor here, Jack.'

'Ianto, I'm going to need some coordinates from you.'

'What's going on, Jack?' There was desperate concern in his voice.

'Ianto, just do it! I need the latitude and longitude of a point in the Bristol Channel. It doesn't matter where – just as long as it's out to sea, away from the shipping lanes, and far enough from any of the islands that a big bang won't cause any damage.'

'And don't forget there's a nuclear power station on the other side,' the Doctor added.

'Okay – can you give me a few minutes?'

'Yeah, take your time. I'm not in any great rush.'

'You're completely insane, you do realise that?'

The Doctor held out his hand. Jack smiled, shook his head, and wrapped the Doctor in a bear hug for a few moments.

'Let's go!'

They ran outside and were almost knocked down by a UNIT truck with a young corporal at the wheel. He leapt from the driver's seat and saluted them as they charged up to him.

'Don't salute!' the Doctor yelled.

Jack lifted the tarpaulin at the rear, peered inside, and whistled.

'Hey, Doctor, there's enough firepower here to blow a hole in the world!'

'Well, try not to make too much of a mess.'

Jack climbed into the cab, slammed the truck into reverse, and revved the powerful engine. The soldier was already sprinting back to the safe area. As he dived through the gates, Martha and Gwen burst through the gap and hurtled towards the Doctor and Jack. Martha seized the Doctor's arm and dragged him towards the gates, her eyes filled with terror. Gwen ran to the driver's side of the truck and grabbed Jack's arm, trying to pull him from his seat.

'What the fuck are you doing?' she screamed.

'Saving the world!'

He pushed her away and Gwen clutched at his coat, her incoherent shrieks filling their ears. He shoved her to the ground, slammed the door, and gunned the engine again. She rose to her knees, tears pricking at her eyes. The truck reversed away from the building, and the Doctor and Martha helped Gwen to her feet.

'He's fucking mad,' she sobbed.

She looked over her shoulder as Jack reversed the truck as far as the perimeter fence.

'He'll get blown to smithereens.'

The Doctor placed his hand on her chin and she found herself looking into his eyes.

'Gwen, you know him better than that,' he said gently. 'He'll be fine.'

He squeezed her hand and pointed to the gates, a two hundred metre dash away. He winked at Martha.

Now, I bet you can guess what I'm going to say next.'

'Oh yes. Just like old times.'

She gave him a huge smile. Gwen looked from one beaming face to the other and back again.

'RUN!' they chorused.

The three friends cleared the distance to the gates in what Pam assumed was an attempt to break the world record. They stormed through the police cordon and came to a halt, panting for breath, back at the SUV.

Ianto was still at his laptop. They conferred for a while as he relayed the on-screen information to Jack. With a guilty glance towards his colleagues, he touched a control on his headset. The comms went dead. Whatever he and Jack were saying was for nobody else's ears. The Doctor looked down at Ianto, trying to read the young man's emotions. Gwen was still weeping on Martha's shoulder.

Ianto murmured softly into his microphone, trying to control the tremble in his voice. Finally he pulled off the headset and looked up from his monitor.

'We've got about two minutes. Time to get clear,' he announced.

He closed the laptop and climbed into the driver's seat of the SUV without another word. Martha put her arm around Gwen's shoulders and helped her into the back seat. Andy started his own car and reversed out of the way. The Doctor, Pam, Dave and Karen got in, lost in their own thoughts. Andy sped out of the car park, the SUV following close behind.

Nobody dared to look back as they headed out of the docks and back to the main road.

Suddenly the Doctor shouted a single word: 'Barrage!'

'Nice one!'

Andy activated the lights and sirens, slammed his foot down, and gunned the car towards the Welsh Assembly Building. Ianto caught on instantly and swung the wheel, tailgating the squad car past the Norwegian Church and towards the Cardiff Bay Barrage.

Several hundred people had gathered along the waterfront, transfixed by the sight of the light flooding from the docks, wondering what on earth was going on. They scattered as the vehicles shot along the narrow path. It was less than a minute's drive to the barrage, and everyone piled out before the engines had stopped running. Even from here, the sound of Dave Probert's machine was clearly audible. The Vortex energy formed a shallow golden dome over the whole of the city, stretching as far as they could see.

The Doctor sprinted off along the barrage and onto one of the concrete islands between the sea-locks. The others followed in his wake, and soon they were all leaning over the metal railings, staring out at the sullen grey waters of the Bristol Channel. He glanced at his watch.

'Now, if Jack's plan works, we should hear the result any second—'

The humming sound died in an instant. Everyone turned in the direction of the docks. The golden glow which had enveloped the city was no more.

'Now …'

The Doctor's voice tailed away.

Far out in the Bristol Channel, a blinding flash illuminated the surface of the water.

A tower of water erupted from the sea and rose high into the air, mushrooming out as it lost speed. A few moments later, a colossal explosion shook the entire barrage. Out of instinct, everyone threw themselves to the ground. A low rumbling sound like a distant earth tremor resounded around the bay for several seconds before fading away.

The massive column collapsed as quickly as it had arisen, and the Doctor got to his feet. He peered over the side of the concrete structure. The sea level had dropped considerably in the aftermath of the explosion, but was now rising rapidly. An enormous circular wave was building on the horizon, thundering towards the shore on both sides of the channel.

'It's a shame we haven't got time to get to Minsterworth.' There was a tinge of sadness in his voice. 'This is going to be one hell of a Severn Bore.'

'Never mind the fucking Severn Bore, you heartless bastard!' Gwen screamed, tears pouring down her cheeks. She ran to the Doctor and pounded her fists against his chest. 'What about Jack?'

Martha leaned over the railings, squinting out towards the mighty oncoming wave.

Barely visible amongst the raging waters, a tiny figure was racing towards them.

'He's okay,' she grinned.

The Doctor shielded his eyes and looked along Martha's pointing finger. Everyone else followed his lead and there was a collective gasp.

'I don't fucking believe it,' Karen muttered.

Jack was standing upright on a narrow flat object, his feet firmly planted a short distance apart, riding the crest of the monstrous wall of water. He gave them a cheery wave as he came closer.

'No way!'

Ianto grabbed the comms headset and patched it through to his laptop. Soon, Jack's voice was issuing from the computer's onboard speakers.

'Did I ever tell you I was the Boeshane Peninsula surfing champion three years in a row? Man, this takes me back!'

As he came into clear view, Pam covered her mouth with her hand.

'He's bollock naked!'

'It was bound to happen,' Ianto muttered.

The wave was losing height and speed as it approached the shore, and soon they could see that Jack's makeshift surfboard was one of the truck doors, blown off in the explosion. He jumped off when he was a few metres from the barrage, and swam strongly towards the sea-lock. A moment later the mass of water smashed into the concrete pilings and drenched the Doctor and his friends in spray. They cried out and retreated to a safe distance. The water subsided again, and they all ran back to the railings. Jack was bobbing in the water beneath, a euphoric expression on his face, roaring with laughter.

'Wow! Now that's what I call a wave!' he yelled, punching the air. 'Sorry about the clothes, ladies - that coat weighs a ton when it's wet, and I didn't fancy drowning on top of being blown up!'

Everyone started laughing and cheering. Martha kissed the Doctor, Gwen kissed Ianto, the Doctor kissed Karen, Gwen kissed Dave, Martha kissed Ianto, Pam kissed the Doctor, Karen kissed Ianto, Martha kissed Dave, Pam kissed Ianto, the Doctor kissed Gwen, Karen kissed Dave, and finally Gwen kissed Andy. His eyes lit up, and the Doctor grinned.

“Don't I get a kiss?' Jack asked over the comms.

'Yes – just before I kill you again, you fucking mad bastard!' Gwen shouted down to him.

The Doctor unfastened a lifebelt from its mountings and threw it to Jack.

'Yeah, right, thanks – like that's going to make any difference to me,' he groaned.

Ianto was tying a length of rope to the towbar of the SUV. He gave the free end to Gwen and she threw it down to Jack. A few moments later, his arms and naked shoulders appeared over the top of the platform. He flashed them a dazzling smile.

'Can someone please get me a towel? I'm freezing my nuts off here.'

The Vulcan Inn, Adam Street, Cardiff, 7.04 p.m.

The Doctor returned from the bar and placed the tray of drinks on the table. As well as the regular crowd, the pub was crammed with people who had been watching the extraordinary events in the Bay. Liz the landlady was working flat-out. She hadn't known such a busy Monday evening for a long time. Everyone was discussing the mysterious happenings of the day, coming up with ever-wilder speculations as to the cause.

Jack, Martha, Gwen, Ianto, Andy, Pam, Dave, Karen and Major Chapman were sitting together in the corner by the door. After the day's adventure, the Doctor had prescribed them all a healthy dose of alcohol to settle their nerves, and they'd headed for one of Cardiff's historic pubs to watch the evening news on TV. Almost everyone was in the corner was in celebratory mood.

Only Karen seemed subdued. She'd missed her copy deadline, and been well and truly scooped. BBC Wales had filled its evening bulletin with a hastily cobbled-together and heavily-spun version of events, studiously omitting any mention of the explosion out at sea or the instantaneous disappearance of an entire warehouse from the docks.

The unveiling of Dave's invention had been completely ignored.

'Perhaps it's for the best,' he'd said during the weather forecast, and the Doctor had nodded his agreement.

'Yeah. It was a nice idea, Dave, but more trouble than it was worth.'

One of the regulars came back into the pub, the smell of fresh cigarette smoke on his breath.

'Dunno know what's occurin' down the Bay, but it's all lit up like Christmas,' he said casually as he returned to his pint.

The Doctor glanced at Jack and a worried expression crossed his face.

'Not again?'

They ran out to the car park beside the pub and looked southwards. High above the docks, a circle of golden light was expanding into the blackness. The glow of the circle dissipated through the low cloud, feathering at the edges to a faint corona. The others joined them, staring up into the sky.

'What the fuck …?' Gwen muttered.

The Doctor turned round and looked at Karen.

'What's the Principle of Conservation of Matter?'

'Mass cannot be created or destroyed, although it may be rearranged in space, and changed into different types of particles,' she replied immediately.

'Exactly!' He pulled a face. 'Or, to paraphrase the great Spike Milligan, everything's gotta be somewhere! And there's another scientific law that we've all forgotten about.' He glared at Dave. 'The Law of Unintended Consequences.'

The circle had stopped expanding, but was steadily increasing in brightness. Suddenly, a deafening whooshing sound reached their ears. It seemed as though a great gale was howling its way inland. Everyone leaned forward to avoid being swept over by its force. Martha shouted something, but her words were torn away by the wind. Something slapped into Pam's face and she pulled it away, holding it at arm's length so that she could see it properly. It was a copy of that week's Big Issue.

A stream of paper, several metres wide and almost as high as the pub, was gushing from the sky. Within seconds the Doctor and his friends were up to their ankles in litter. The rest of the customers had come outside to see what was happening, and were struggling to stay upright as the blizzard of paper swept around them.

'Fucking brilliant!' Gwen cried. 'It's like a tickertape parade!'

'I think we'd be safer indoors!' Jack bawled.

They took the hint and all ran back into the pub, slamming the door behind them.

For a few minutes everyone thronged by the windows as the torrent of paper continued, with only occasional comments from the crowd. When it was about knee-deep it started to subside, but continued to rain down.

'Oh my God, it's like the morning after a match day,' Gwen gasped.

'This is going to take some clearing up,' Liz murmured as her customers wandered back to their drinks.

'Nice bit of overtime for the council though,' Ianto replied.

The fall had eased off by the time they finished their drinks, and only small pieces of paper floated past the window as they left the pub.

The Doctor and Martha kicked their way through a deep drift which had gathered in the doorway and stepped outside. They found themselves trudging across a thick bed of paper debris half a metre or so above ground level.

Jack joined them just in time to hear Pam say, '1941.'

'No way!' he cried. 'There's at least four of me there already – I can't go there again.'

'Not the year 1941,' the Doctor explained patiently. 'The 1941 train from Cardiff Central. Pam's got to get home somehow.'

'I can't see the trains running tonight,' Andy said. 'If leaves on the line or a bit of snow bugger them up, they'll have no chance in all this.'

'Well then,' the Doctor said, taking Pam's hand, 'I'll give Pam a lift. It's not far to the Bay. We'll take the TARDIS.'

Cardiff Bay, 8.14 p.m.

They'd hardly seen a soul on the walk to the Millennium Centre. The downpour had clogged the streets. No traffic was moving anywhere, and near the railway station a gang of small children were rummaging in the pile of paper.

The TARDIS was in its usual spot near the water tower when the group of friends arrived at Roald Dahl Plass. The Doctor fished the key from his pocket, unlatched the door, and looked around. Pam stood beside him. His pals from Torchwood, along with Andy and Major Chapman, were smiling, but Dave and Karen looked sad. It was time for goodbyes again.

The Doctor stepped forward and held out his hand.

'Dave, it's been a pleasure. You're a genius. Shame it didn't work out, but full marks for effort. One thing's for sure, you've saved me from the nightmare of a boring day kicking around in Cardiff.'

'Thank you, Doctor.' He cheered up slightly and shook the proffered hand. 'I hope we meet again some time.'

'So do I. If we do, I'll take you to the library. You'll love it!'

He turned to Karen and smiled.

'And don't worry about not getting the big headlines this time. I knew a journalist once who couldn't report anything we got up to – they'd have locked her up in a mental hospital.' She smiled. 'Of course, if you really want a story, you can always come with me. There's plenty of room.'

'Believe me, there's never a dull moment with this guy,' Martha added.

Karen shook her head.

'It's really nice of you to offer, Doctor, but no thanks. I don't think I could take the pace.'

'No problem. It's been fun, though, hasn't it?'

'Oh fuck aye!' she beamed. 'See you around.'

She stood on tiptoe and gave him a quick peck on the cheek. Then she and Dave linked arms and walked off towards the city centre, sending a flurry of paper into the air with every step they took.

Major Chapman walked forward and shook the Doctor's hand.

'Thanks for your help. I don't know what we'd have done without you.'

'UNIT never does,' he replied with a wink. 'It's a good thing I stick around.'

Chapman snapped a salute and the Doctor groaned.

'Don't do that!'

The young officer gave him a wry smile and bade the rest of them goodbye before strolling off towards the Assembly Building.

'So here we are again,' Martha said softly.

The TARDIS door had opened slightly in the breeze, and she could see the soft glow of its interior through the gap. It brought back memories of their time together. The Doctor seemed to read her thoughts as she gazed past him.

'What do you think? One more trip for old time's sake?'

'No, mate.' She shook her head and gave him a sad smile. 'I owe Tom a night in for once.'

'Fair comment.'

He hugged her and she kissed him.

'See you soon.'

'And we'll see you soon as well,' Jack said firmly. He winked at his old friend. 'You never know when you're going to need our help, after all.'

The Doctor shook his hand, then Gwen's, Ianto's and Andy's in turn.

They stepped onto the lift platform and raised their hands in farewell. Pam watched, speechless, as they descended into the Hub, deep beneath her feet. The paving slab rose back up to fill the space, and there was no indication that anyone had ever been there.

'And then there were two!'

His voice echoed from the front of the Millennium Centre. He turned to look into her eyes. 'You could come with me.'

'No thanks, Doctor.'

'Okay.' He nodded. 'Aberdare it is.'

He led her into the TARDIS and shut the door behind them. He ran his fingers over the central console and the controls lit up instantly.

'Oh yes! All fuelled up and ready to go!'

'Can you do me a favour?' she asked.

He stopped flicking switches and moving levers, and looked up at her expectantly.

'Don't drop me off by the pub. After today, a spaceship appearing from nowhere would be the last straw. If you could take me a bit nearer home, that'd be great.'

'Yeah, no problem. Let's have a look.'

He peered at a small screen set into the console.

'Right – I've got a country park, with a couple of big lakes and a bus stop nearby – it seems nice and tucked away.'

'That's perfect! I can walk home from there.'

'Okay, let's go.'

He pressed a large button and grinned. The central column began to rise and fall, and the groaning sound Pam had heard the previous evening filled her ears. No sooner had the sound begun when it faded away again, and Pam looked worried.

'That didn't take long.'

'I know – top of the range, this is! Nought to c in 3.2 seconds.'

She turned to leave, but he ran to the door and stood with his back to it, blocking her exit.

'Final answer?'

'Doctor, I can't. I've got a life here. Anyway, it's been the trip of a lifetime already.' She kissed him. 'Thanks for everything.'

'No – thank you, Pam.' He moved aside to let her pass. 'See you around.'

'No offence, but I really, really hope not!'

She smiled, opened the door, and stepped into the night air. She turned to see him framed in the doorway, his hand raised in farewell.

'Bye, Doctor.'

'Pob hwyl, Pam,' he said softly.

The door closed and she was left in semi-darkness.

She turned away with a tear in her eye and walked to the bus stop, just a few metres away.

Immediately she realised that something was wrong. The bus shelter was made of timber, instead of the vandal-proof plastic or concrete structures she was used to in the valleys. There was a metal post with a timetable just outside the shelter, and Pam looked at it with a growing sense of alarm.

The sign at the top said COSMESTON LAKES. It was a place she'd only ever heard of, somewhere between Barry and Penarth. Without stopping to think, Pam sprinted back towards the TARDIS.

'Doctor!' she screamed. 'We're in the wrong place!'

She was a few inches from the door when the groaning sound started up again. She stood and watched helplessly as the TARDIS slowly faded from view. Presently the noise died away too, leaving her alone and miles from home.

Pam sat in the shelter for a couple of minutes, wondering how on Earth she would explain this to Vicky the following day. She shrugged, took out her phone, and dialled the number for Directory Enquiries. She'd have to take a taxi home from a place she'd never been to before. In that respect at least, Pam Griffiths had had a fairly average day.

THE END

St Donat's Arts Centre, 1.22 p.m.

Dave Probert was the centre of attention in the bar, a glass of wine in his hand and a satisfied smile on his face. Around him was a fascinated group of politicians, industrialists, businessmen and academics, all eager to buttonhole him for a couple of minutes' worth of private chat. A little clique of media people lurked near the bar, hoping for a snappy soundbite for the headlines. Karen was chatting to a couple of technicians from S4C. Everyone agreed that the professor's demonstration had been one of the most remarkable things they'd ever witnessed.

Just over three hours before, he had stepped from the podium and walked up the aisle between the rows of seats, rather like a magician seeking a volunteer for his next trick. In one sense, that was exactly what he was. There had been no shortage of willing hands in the air.

His eyes had settled on Karen Samuels, who had shown such a keen interest in his talk. He'd invited her to join him at the front, and to bring a newspaper with her. Rather timidly, she'd dug out that month's Cosmopolitan from her bag, risen from her seat and followed Dave to the front of the room.

He had shown her how to place the magazine into the feed mechanism of his invention. Intrigued, she'd watched as he keyed some commands into its control panel. A webcam positioned less than half a metre away, and transmitting to a large video screen behind the podium, had allowed the rest of the room to share Karen's viewpoint as the machine came to life.

'Ladies and gentlemen, as you can see, I have nothing up my sleeve,' he'd quipped, and his audience had chuckled. 'And now, please watch closely.”

A low humming had filled the room. It had grown louder before cutting off abruptly, and everyone in the room had gasped in unison.

The magazine had vanished.

The glass plate where it had lain was empty, and Karen had automatically reached into the space, her fingers exploring the void for themselves.

'That's impossible!' she'd cried after a few moments.

'No – that's science!' Dave had replied.

He'd removed a flash drive from the device and handed it to Karen with a grin.

'There you go – this month's Cosmo, reduced to a more manageable size.'

Karen had been speechless, and Dave had turned to face his audience again.

'It's been converted into a PDF file in a few seconds, but with the superfluous text filtered out. All the advertisements, all the repetition, and all the redundancy are stripped away by intelligent software, leaving just the key information. How long would it have taken you to scan every page by hand? Now, you can read it on any computer, email it to anyone in the world, or burn it to DVD so you can store it forever. That's the beauty of this technology – there's no time-wasting, no nonsense, and most importantly, nothing to go into the recycling bag.

'Even now, down in Cardiff, my team is starting to process the entire paper records of the university's IT Department. We reckon it should take a few hours to convert everything to PDF. But of course, if we do get any teething problems, they might have to work through lunch.'

The audience had laughed again. Gradually the laughter had turned to applause. It had spread throughout the theatre until everyone was standing, cheering wildly.

Dave had stood with a modest smile on his face, one hand on his invention, as camera flashes lit up the room. The public launch of Project Précis had been nothing short of a triumph.

Karen finished her glass of wine and excused herself, heading straight into the toilets. She locked the cubicle door behind her and switched on her mobile phone. If she could ring her story through to the newsdesk, her editor could run the story of Probert's invention before the evening news broadcasts were aired. Although 24-hour TV news coverage and the internet were largely killing off local newspapers, print journalists still enjoyed the thrill of the chase for an exclusive story. Scooping the competition was a time-honoured tradition in the press, and this would be Karen's biggest story so far.

She hit the speed-dial and waited. Nothing happened, and she checked the display. There was no signal. Tucked away on this isolated part of the Welsh coast, her phone was out of range of a mast.

'Fuck it!' she hissed. 'Useless piece of shit!'/div>

She thrust the phone into her pocket, left the toilets, and walked into the foyer, looking around for a payphone.

She was making her way towards the reception desk when the door flew open and a tall slim man charged in, colliding with her in his haste. He stopped short and put his arm out to steady her before she fell against the desk.

'Oh, I'm so sorry! Are you okay?'

'Yeah, I'm fine, thanks. No damage done.'

Karen looked him up and down, taking in his smart suit, long coat and spiky brown hair. He looked rather like an eccentric art teacher. His eyes gleamed as they regarded each other for a moment.

The door swung open again and a uniformed policeman ran into the foyer, followed by a casually-dressed blonde woman. They stood panting at the tall man's side, but he seemed to have taken the run in his stride.

'You might be able to help us, actually. We're looking for Professor Dave Probert. Do you know where we can find him?'

'Yeah. But the press conference finished ages―'

'Doesn't matter!' There was a definite note of urgency in the policeman's voice. 'We still need to speak to him. It's really important.'

'He's just down there – you can't miss him, he's the main attraction.'

Karen pointed them towards the theatre and smiled.

'But I need to speak to him as well, and I was here before you. I'll only be a couple of minutes, I need to make a phone call first.'

'What is it with women and phones?' the tall man cried. 'You're all obsessed with them!'

He grabbed the blonde woman's hand and sprinted off down the corridor, while she struggled to keep up with him. The policeman was a few metres behind. Karen shrugged and leaned on the reception desk, wondering how far she'd have to drive to find a phone box in this part of the country.

The Port of Cardiff, 1.29 p.m.

Julie slammed the phone back into its cradle and swore loudly. Khan looked across at her, his eyebrows raised.

'Sorry,' she muttered.

'Still no joy?'

'Straight to voicemail every time,' she grumbled. 'I don't know what the hell we're going to do!'

'Plead innocence?' he suggested with a wry smile.

'This isn't funny!' she snapped. 'It's already happened all over south Wales, and it keeps spreading. At this rate, it'll hit London by tomorrow lunchtime at the latest – and then we'll be well and truly fucked!'

She got to her feet and leaned over the railings, glaring down at the source of their anger. The machine was glowing faintly orange, and its humming was threatening to overwhelm their conversation. Khan picked up the phone and hit the redial button. All they could do was to keep trying.

St Donat's Arts Centre, 1.29 p.m.

Dave was chatting with a couple of ministers from the Senedd when the doors burst open amid loud shouts. Everyone turned to stare at the three new arrivals, who stood framed in the doorway. A piercing fingers-in-mouth whistle rang out above the hubbub, and immediately the room fell silent.

'We need to see Professor Probert!' a clear voice announced.

'That's me.'

Dave walked into the middle of the room, wondering what the fuss was about. The tallest of the three strangers stepped forward and extended his hand to the bemused professor.

'Great to meet you, Professor. I'm the Doctor – can we have a word?'

'Doctor who?' Dave replied.

'Don't start all that,' the stranger groaned.

'I demand to know who you are! You've gatecrashed a private function, for one thing …'

'We just want to ask you a few questions, Professor.'

Andy had appeared at the Doctor's side, his warrant card in his hand.

'Would you mind co-operating with us, sir?'

Dave's face spoke of his reluctance.

'I'd hate to have to make this an official matter,' Andy hinted.

'Maybe if you had a look at my credentials …'

The Doctor pulled his psychic paper from his pocket and handed it to Dave.

'UNIT?' Dave looked concerned as he read the paper. 'I always thought they were a myth.'

'No, UNIT's real, and so is Torchwood. I help them out from time to time – and this is one of those times when they need my help. And we really need your help, Professor.'

Dave nodded slowly. The Doctor led him to a corner of the room and ushered him into a chair, with Andy and Pam flanking him in case he decided to make a run for it. The Doctor flipped a chair around and sat down, resting his elbows on the back, gazing into the professor's eyes.

'So, what can I do for you – Doctor?' he asked, sounding defeated.

'Tell me how your machine works,' he said in a straightforward voice.

Not on your life!' Dave started to rise to his feet, but Andy pushed him back into his chair gently. 'It's taken me twenty years to develop this technology – I'm damned if I'm going to reveal its secrets to a complete stranger.'

'The thing is, Professor, I'm afraid it's gone a bit wrong,' the Doctor said quietly.

'Impossible!' Dave leaned back, his self-assurance unruffled. 'We've been testing it for weeks without any problem. And the demonstration was perfect – flawless.'

'Okay – if you won't tell me how your invention works, will you at least show me? As one scientist to another. Nothing wrong with a bit of peer review, is there?'

Over the centuries the Doctor had found that the soft-soap approach, combined with a bit of mild hypnotic suggestion, usually worked. This was no exception.

'With pleasure.' Dave smiled. 'It's in the next room.'

He led the Doctor and his companions through the bar, exchanging pleasantries with friends as they passed, and back into the theatre. The house lights were on, and the place seemed much bigger when empty. The machine was still standing alongside the podium, and Dave led them up to it, a confident smile on his face.

'Here it is, Doctor. Has anyone got a newspaper?'

Pam handed him that day's Metro, and everyone watched as Dave fed it into the machine.

A few seconds later, even the Doctor was lost for words as the paper vanished. Dave removed an SD card from a slot at the rear and handed it to him.

'See, Doctor, it's as simple as that – completely harmless.'

'Have you ever read The Hitch-Hiker's Guide to the Galaxy?'

The Doctor was already on his haunches, examining the device in minute detail, and he looked up at Dave with his eyebrows raised.

'Yes, a long time ago,' he admitted.

'That was what the first edition of the guide said about planet Earth.' He stuck his sonic screwdriver into the feed mechanism and pulled a face. '"Harmless." Then they revised it to "Mostly harmless" – a bit like your gadget, really.'

Dave looked offended and drew himself up to his full height.

'I can assure you, Doctor, this "gadget", as you call it, is as safe as houses.'

'Yes, it is. I've just given it the once-over, and it's squeaky clean.'

He sprang to his feet and pocketed his screwdriver.

'But it's not this gadget I'm worried about.'

He advanced towards Dave and stooped down so that their eyes were only a few inches apart.

'Professor Probert,' he continued in a near-whisper, “where's its big brother?'

Cardiff Central Police Station, 1.32 p.m.

Ianto looked up from the laptop and smiled across at Gwen. She was still poring over the online records of every call received since the previous evening. The number of calls was increasing by the minute, and the affected area was growing in size. They'd received their first call from Llantwit Major a couple of minutes before, and their colleagues in Avon and Somerset were in constant radio contact as the effect spread across the Bristol Channel.

'It's down by the Bay!' he announced, a triumphant note in his voice.

'What is?' Gwen asked absently.

'Whatever's causing all this.'

Gwen swung round in her chair and gave him a huge smile.

'Do tell!'

'I've correlated every reported incident against our timeline, and I've come up with this.'

He turned the laptop so Gwen could see the screen.

Vincent Price and Kathy Swanson looked over his shoulders, each as baffled as the other. The display showed a satellite photograph of the city and its surrounding area, with a series of concentric circles superimposed on the image.

'What are we looking at, exactly?' Price growled.

'Here's the hospital.' Ianto pointed to a large complex north of a dual carriageway. He proceeded to point out other key features of the city as he spoke.

'Here's where we are; here's the cafe where we first noticed what was going on; here's Waterstone's―'

'The bookshop?' Kathy said in surprise.

'Yeah – they rang us earlier to say they'd had to close,' Gwen explained.'Apparently they had nothing left to sell except CDs and mugs.'

'Anyway, once I'd collated the times of the reports, I was able to plot them against the locations.' Ianto turned to face the two police officers. 'Whatever's responsible for all this is generating some sort of wave, propagating from a central source. It's like ripples on a lake, radiating out from that source. So I ran the figures through one of our programs, and I got this.'

He slid his finger over the trackpad, zooming into the centre of the innermost circle. The image resolved into a birds-eye view of a warehouse, surrounded by cranes, lorries, and shipping containers.

'I know where that is,' Kathy announced. 'It's the Associated British Ports facility.'

'We'd better get a team over there right now.'

Price was in severe danger of smiling, but he managed to control himself.

'With respect, I don't really think a team will be much good, Chief Superintendent. This is a job for the experts.'

Ianto closed the laptop and picked up his coat. Price stepped out of his way, hopelessly out of his depth and unconsciously deferring to the younger man.

'Gwen, can you radio Andy and get him to put the Doctor on? We're going to need him ASAP. I'll tell Jack to meet us by the main entrance to ABP. Better get Martha down there as well, in case anyone gets hurt. See you outside in two minutes.'

'Yeah, sure thing!'

Gwen grabbed the radio as Ianto ran from the room, closely pursued by the two officers.

St Donat's Arts Centre, 1.38 p.m.

The Doctor was leading Dave, Andy and Pam out of the building when Karen ran up to them.

'Professor! Professor! Sorry to interrupt – I was just wondering if I could have a few minutes with you.'

'This isn't really a good time, Miss Samuels,' Dave replied, one hand on the door frame.

'Please, Professor – this is a really big story. If I can get it into tonight's paper, it'll make my career!'/div>

'You want a story?' The Doctor stopped in his tracks, swung round, and walked back to the doorway. 'Come with us, I'll give you a story!'

'Who are you, then?'

The Doctor grinned.

'I'm the Doctor.' He indicated his companions. 'This is PC Andy Davidson, this is my friend Pam. And here's your headline: Extra-terrestrial helps top secret organisation save the human race from disaster for the umpteenth time.'

Karen stared at him, open-mouthed, for a moment.

'You're having a fucking laugh!'

'No, not at all! Actually, make that: Incredibly brilliant and stupendously handsome extra-terrestrial helps top secret organisation save the human race from disaster for the umpteenth time.'

'You're serious, aren't you?'

Karen might not have seen six impossible things before breakfast, but she'd seen one impossible thing before lunch. Nothing could shock her now.

'I'm completely serious. And extremely modest to boot.' He winked at her. 'You'll have the biggest story of the year. Just one thing – have you got a tape recorder?'

'Nobody uses tape recorders any more.' She laughed, and took an MP3 recorder out of her pocket. 'It's all digital these days.'

'Yes, I think that might be part of the problem.' He gave Dave a meaningful look. 'Still, hang on to it – you're going to need it where we're going!'

Andy's radio crackled into life, and he walked away to answer it. He returned a few moments later and handed it to the Doctor with a wry grin.

'It's for you.'

The Doctor held it to his ear and listened as Gwen babbled Ianto's findings to him. His expression grew more and more worried as she spoke, and he turned to Andy.

'How far's Llantwit Major?'

'Couple of miles away,' Andy replied casually. 'Why?'

“It hit there about five minutes ago.'

He gave the radio back to Andy and frowned at Karen.

'Out of interest, where's your notebook?'

'In my bag.'

'Are you sure?' He grinned. 'Fifty-fifty? Phone a friend? Ask the audience? Is that your final answer?'

Karen rummaged in her bag for her shorthand pad, but there was no sign of it.

'It was here a minute ago,' she said after a few moments.

'Oh, I dare say it was,' he winked. 'Look!'

He pointed to the noticeboard just inside the door.

As his companions turned to look at it, the posters pinned to it winked out of existence. There was no slow dematerialisation, or unnatural energy shimmer. All the paper simply disappeared before their amazed eyes. Everyone turned to look at the desk. A moment before, there'd been a display of leaflets and programmes in a plastic dispenser. Now, the counter was completely empty.

'Oh, my God,' Dave said in a low voice.

'Believe me now, Professor?' he asked, trying not to sound smug.

'Yes, I believe you. What the hell's happened?'

'It just so happens I've got a theory – I'll tell you on the way back. And you'd better sit in the front. You're navigating!'

Next Episode

Episode 6

The Port of Cardiff, 9.46 a.m.

In an anonymous office amongst the cranes and containers of Cardiff's port facilities, dozens of white-coated technicians working in shifts had been monitoring a bank of display screens for the last two weeks. In a neighbouring warehouse, over the past six months, Dave Probert's brainchild had slowly taken shape. A hand-picked group of researchers in electronics, artificial intelligence, software engineering, and mechanical engineering had assembled his creation according to his brilliant and subtle design specifications. Strict security precautions had ensured that only the prime minister, a few senior cabinet members, top-level government advisers, the military top brass, and Probert's own team knew what Project Précis was designed to achieve.

Project Précis was classified Top Secret, and had been ever since Probert had first mentioned his idea to a colleague a couple of years before. Some months later, the prototype he'd demonstrated to an invited audience in Westminster had convinced the prime minister to fund his R&D proposal.

At every stage of the construction, he had visited the site personally to inspect the progress on Project Précis. The engineering work, requiring tolerances of hundredths of a centimetre, was perfect. All the component parts been tested and double-tested. Each line of the software had been coded, debugged, checked, and refined until every possible bug had been eliminated. Only was Probert was satisfied with the result of everyone's work did he announce his press conference. His academic reputation rested on a successful launch.

From a mezzanine floor overlooking the control room, a post-doctoral researcher named Julie Jones surveyed the technicians. At her workstation, the combined results from each set of monitoring instruments were summarised into one at-a-glance printout. She had been Probert's star pupil from her earliest time at university, and he had immediately recruited her to oversee the day-to-day affairs at Warehouse 17. Julie had supervised the construction work under his watchful eye, and knew every detail of the device. For this reason, Probert had delegated her to look after the initial switch-on of the full-scale model, while he was busy schmoozing with the politicians, businessmen and media down the coast at St Donat's.

Julie felt a pang of anxiety as she examined the latest set of readings feeding back from the device next door. One of the monitors was registering some unanticipated activity. She ran the test program again and got the same result. She caught the eye of one of the senior programmers and signalled down to him. Half a minute later, Mohammed Khan appeared at her side, scanning the printout quickly.

'2011 last night?' he murmured. 'I was here then – nobody noticed anything unusual. I suppose it could have been a faint trace of a solar flare – or just a glitch in the power supply.' He shrugged and gave her a reassuring smile.

'Do you think we should tell Dave?'

'No, I wouldn't worry about it. It's the only blip in the entire fortnight. He'll be in the middle of his presentation, anyway.'

'Yeah, you're right. It can't be anything serious.'

She glanced up at the clock. It was approaching 9.50. She flicked a switch and spoke into a microphone mounted on her desk.

'Ladies and gentlemen, Project Précis will go live in just over ten minutes.' Her voice rang out across the entire office building. 'Please be sure you are at your workstations for the initialization of the device. Thank you.'

Khan winked at her and headed back towards the stairs.

The Vale of Glamorgan, 1.02 p.m.

The police patrol car barrelled along the A48, its lights and sirens scything a clear path through the queue of traffic.

The Doctor was in the passenger seat, using Pam's mobile phone to get regular news updates. It seemed that the mysterious phenomenon was self-propagating – the lunchtime headlines from BBC Wales announced that the effects had spread as far as the Valleys, and almost as far west as Cowbridge. Initial reports were also starting to starting to filter through from the outskirts of Bristol. Occasionally Andy's radio would crackle into life as Gwen relayed the latest information.

'If this carries on, we're going to lose everything,' Andy said.

'Oh, I wouldn't worry about that. I'm sure we can sort this out somehow.'

The Doctor started scrolling idly through the phone's menus.

'Pam, can this get Radio 2?' he asked casually.

Pam, holding onto the back of his seat in fear of her life, squeaked a reply.

'Brilliant – I love Ken Bruce's show! I'll have to get one of these,' he enthused.

A brown signpost at the next junction pointed the way to St Donat's. Andy hurled the car off the dual carriageway and onto a smaller country road. An approaching tractor had to swerve into a hedge to let them shoot past.

'Not far to go now,' he remarked, and Pam breathed a sigh of relief.

'Thank God for that – just let me know when it's safe to open my eyes.'

St Donat's Arts Centre, 9.46 a.m.

'Another dream we were sold in the 1970s was that of the "paperless office",' Probert told his audience. 'Every couple of months Tomorrow's World used to promise us a future in which paper would be a thing of the past. And yet look at the amount of paper we generate these days. Yes, we have "paperless gas bills" and "paperless banking", but in reality the paperless office is just a myth. There's always got to be some sort of hard copy backup somewhere in the system.'

He called up a new slide. This one showed a curve rising slowly at first, but increasing sharply in gradient as it departed from the origin.

'This is an approximate representation of the information content of human society over time, which I've adapted from Georges Anderla's work in the 1970s.'

He indicated the origin of the graph, and Karen grinned. She'd come across Anderla's model of information some years before. She was also aware that almost everyone else in the room was floundering by this point.

'Here, we have the start of the Common Era,' he said. 'In Anderla's model, the sum total of human knowledge can be summarised as one unit of pure information, in the mathematical sense. According to Anderla's hypothesis, two thousand years ago it would have been possible for one single person to know everything that there was to be known. And it took all of fifteen hundred years until the quantity of information doubled.'

He followed the gradually rising curve with his pointer, until he hit a vertical line.

'When that happened, it was the time of Michelangelo, Leonardo, and the Renaissance. It was a major breakthrough, at least in Europe. Human society took a leap forward as the total amount of information doubled. Each increase in information lays the groundwork for the next increase. It's a slow process at first. But as time moves on, the development accelerates.'

He traced the graph with his laser pointer. Karen overheard a couple of sharp-suited media types behind her, wondering what the old man on the podium was talking about.

'It only took about 250 years until the next doubling occurred – and Humankind entered the next step of its intellectual evolution. That was the start of the Industrial Revolution, the Enlightenment, the birth of the scientific method, steam power, the mass-production of consumer goods, and the beginning of the modern era.'

He picked out the next step of the graph, and Karen nodded. Most of the people around her were completely lost. Undeterred, he continued tracing the graph with his pointer.

'We hit eight units of information here – around the year 1900. There were major revolutions in music, art, and literature, the birth of radio, the dawn of the atomic age, the foundations of psychology, and the beginnings of modern medicine. Not even the most polymathic of people could have become au fait with all the developments of human knowledge by this stage.'

He continued to trace the curve upwards and looked out at his largely unappreciative audience.

'And this is the problem we face today. The information content of our society increases exponentially over time. There are more journals and more papers published in more and more specialised fields every week of the year. It's impossible for any researcher to keep abreast of all the developments in even a very narrow academic niche. And every new piece of information needs to be published, catalogued, indexed, cross-referenced, peer-reviewed, cited, and archived for posterity. It's the foundation for the next stage in our evolution as a species, after all.'

Cardiff Bay, 1.17 p.m.

Captain Jack Harkness had made his way back to the Hub and was sitting at his computer screen, trying to analyse the time-line which Gwen and Ianto had emailed to him. After dropping Martha off he had headed straight back to the Bay, figuring that some part of his vast collection of alien technology would prove useful. However, after running every program he could think of, and even after skimming the Torchwood archives back as far as 1879, Jack was still none the wiser. He cast a wistful glance towards Toshiko's absent workstation.

'I could do with your help, Tosh,' he murmured. 'This has got me beat!'

The only reply was a mocking silence.

Jack took another gulp of his coffee and leaned back in his chair. It was up to the Doctor now.

St Donat's Arts Centre, 9.51 a.m.

Dave Probert called up the next slide. Karen recognised this diagram as well – it was the mapping of an iterated periodic function known as a Feigenbaum graph. He pointed out the blurred section at the right-hand side.

'Georges Anderla missed one vital point. He never had to take the effect of the Internet into account. Now we have all manner of charlatans making spurious claims, which are presented as fact. We can't separate the wheat from the chaff. If we do the mathematics, we eventually reach a point where information doubles and doubles and doubles – until the graph becomes chaotic. According to some researchers, we will hit this transition point soon – very very soon, in fact.'

The next slide flicked up onto the screen. It was a satellite picture of Hurricane Katrina, on course to skirt New Orleans entirely, according to the US Weather Bureau.

'The problem with chaotic systems is that we try and use them to make sense of our lives, because we don't understand the true nature of non-linearity. I'm sure we all remember Michael Fish's famous forecast of 1987, when he told us that there wasn't a hurricane on its way. The fact is that the weather forecast can never be accurate, because there are too many variables in the ecosystem for us to make predictions. The best we can hope for is an educated guess based on past experience – or a sound-bite that comes back to haunt the Met Office every time they get it wrong.'

His audience chuckled. He pressed another key on his laptop and the slide changed. It was the Mandelbrot Set, the iconic and instantly recognisable representation of Chaotic Dynamics.

'In the same way, the vast increase of information in the collective human consciousness makes it impossible to assimilate everything we read and hear and see. As a society, we're heading for a collective nervous breakdown. We have to address the problem of unmediated information increase now – or risk the imminent collapse of our civilisation altogether.'

University Hospital of Wales, 12.53 p.m.

Martha was addressing a hastily convened emergency conference. Ranged around the table were the top consultants, clinicians, nurse managers, IT experts, administrative chiefs, and Staff Nurse Maria Bowen. Martha had insisted that her old friend should be allowed to sit in on the meeting.

Her extensive experience working with UNIT and Torchwood – not to mention her time spent travelling with the Doctor – had prepared her for pretty much any eventuality, but none of the people around her had ever experienced anything like this. In spite of frequent Major Incident exercises, nothing had prepared the emergency services for the present crisis. Until she'd walked into reception and presented her credentials to a bemused security guard, nobody had had the first idea what to do.

Professor Alan Marsh, one of the most experienced cardiothoracic consultants in Wales, was pressing her for more information as she outlined the situation.

'We saw the wave at first hand, Professor,' she replied. 'We were in the Bay when the effect occurred. It must have spread out from its original source and reached this point soon afterwards. We were just wondering ourselves what was going on when Maria rang me.'

'By "we", I presume you mean Torchwood?' a hard-faced woman at the end of the table demanded.

Maria knew her by sight. Helen Williams was a senior administrator, and was feared throughout the entire NHS Trust for her fierce temper and humourless approach to people.

'Yes, ma'am.' Martha gave her a sweet smile.

For a supposedly Top Secret organisation, Torchwood's activities had made them notorious throughout South Wales. Most high-level people in local government or the public services lived in fear of the day when the black SUV with the tinted windows appeared in their car park.

'But so far you have no idea what's caused this mysterious event, or what we do to stop it?' the same woman added.

'We're working on it, ma'am,' Martha replied. 'My colleagues are doing everything that they can to identify the source and – hopefully – put a stop to whatever's going on.'

'Staff Nurse Bowen,' Helen Williams said in a cold voice, turning to face Martha's old friend. 'I believe you initially decided to involve Torchwood in this.'

'No, ma'am,' she said honestly. 'I just decided to phone Martha – Dr Jones. It was a personal call. We were at the Royal Hope together when ... Well, I'm sure you all remember what happened.'

A low murmur went round the table.

'I thought Martha might have some idea what was going on.'

Helen Williams opened her mouth, but Professor Marsh spoke first.

'Well, it's a good thing you did, Nurse Bowen. I'd rather have Torchwood on our side than working against us.'

Nobody else spoke – Marsh was the most senior person at the meeting, and the others would have to accept his decision. He turned to face Martha again and gave her an encouraging smile.

'So, Dr Jones, what do you need to know?'

St Donat's Arts Centre, 9.55 a.m.

Dave Probert flourished a sheaf of paper, and Karen's ears pricked up.

'Some years ago, I gave this paper on the future of information storage, at a conference in the United States. I stood on a stage like this and addressed the leading minds in the field. I experienced the same reaction then as I'm experiencing now from most of you. Most people's eyes glazed over within the first ten minutes. My work was laughed out of court. I was denounced as a fraud and a dreamer, by the sort of small-minded people who thought that we'd still be using big reels of magnetic tape to programme their computers in the year 2009.'

He was approaching the climax of his presentation, and the excitement in his voice was palpable.

'I've been involved with what we now term "information technology" since its infancy,' he smiled. 'I've also been a fan of science fiction since I was a teenager. People like me have never been afraid to look at what the experts say is possible, and fly in the face of received wisdom. If this is science-fiction, then I'll go and work for Gerry and Sylvia Anderson.'

He rode the wave of laughter, walked off the stage, and wheeled a bulky device about the size of a photocopier back to the podium. “Ladies and gentlemen, please allow me to present the future of data storage.” He glanced up the clock. It was nearly 10.00. In just a few minutes his demonstration would begin in earnest.

For no reason that she would ever be able to explain, Karen shivered.

Next episode

Episode 5

St Donat's Arts Centre, 9.33 a.m.

While the Doctor and his friends were recovering from the events of the previous night, and long before they decided that breakfast was called for, the sound of a passenger jet approaching Cardiff-Wales Airport interrupted Professor Dave Probert's speech.

Probert was a small lean man in his seventies; bald, slightly stooped, his hands liver-spotted, his eyes rheumy, but still smartly-suited and clearly-spoken, he exuded a youthful enthusiasm as he spoke. He selected the next slide of his Powerpoint presentation with a decisive stab of his finger, and stepped aside so that his prospective clients could see the projector screen.

An invited audience of the key movers and shapers of the Welsh economy had gathered to witness the unveiling of the latest scientific advance. The theatre of St Donat's Arts Centre, on the Bristol Channel coast, was filled to capacity for the much-heralded announcement. The latest image was a photograph of a metal shelving unit, reaching from floor to ceiling and crammed with dusty box files bursting at the seams with papers.

'Ladies and gentlemen, I regret to say that you're all too young to remember what it was like when I left school.'

Probert picked up the thread of his talk as if the aeroplane had never been there. After many years of working in London, his Welsh accent broke through when he became excited.

'I won't tell you how old I am, but when I started work, it was His Majesty's Stationery Office.'

His audience gave an appreciative laugh. He'd borrowed this witticism from a former colleague, and it never failed to raise a smile. He continued, well into his stride now.

'I remember the days when everything needed to be signed, countersigned, posted, forwarded, stamped, dated, and filed in triplicate. I used to run between offices most of the day with mysterious folders tucked under my arm. As a naïve young man in the War Office, I thought I was going to work with James Bond. Instead, I spent most of my time working with Basildon Bond.'/div>

This also got a laugh. Probert had practised his presentation in front of a mirror over several days, and knew exactly how to deliver his best lines.

'I worked in the Civil Service for twenty years before I moved across to academia. That was almost as bad. I used to lie awake at night, wondering if we were going to bury every trace of our civilisation under a mountain of paper'

The audience chuckled again. He smiled to himself. His talk was going very well.

In the fourth row, Karen Samuels shifted in her seat. When her editor had offered her the position of Technology Correspondent at Wales's newest daily newspaper, she hadn't expected to sit through one man's reminiscences of his life in pen-pushing. Then again, as the only staff reporter with A levels in the sciences, she'd been the sole candidate for the role. She turned the page of her notebook over and wondered idly when the promised refreshments would be served.

Cardiff City Centre, 12.09 p.m.

Ianto swung the black SUV around the tight bend and gunned it into Greyfriars Road, cutting up a delivery van emerging from a private car park. The van driver sounded his horn, and Ianto gave him an apologetic wave as they sped past. Wedged against the nearside rear door, Pam closed her eyes and swore loudly.

On the other side of the vehicle, Gwen was keying a set of commands into a laptop. Between them, Martha was perched on the Doctor's lap. All three were trying to read the laptop screen as it bounced up and down. Even Jack, who had cheated death at least a thousand times, was unusually pale, gripping the sides of the passenger seat as they approached the corner of Park Place.

The SUV shot across the junction just as the lights changed to red. A group of students waiting to cross the road jumped back in alarm, and more horns blared. The lunchtime traffic was backing up from North Road as usual, and the outgoing vehicles were at a standstill. Ianto wound the window down and peered ahead. A silver people-carrier was waiting astride the white lines, effectively blocking both lanes, and he leaned his head out of the window.

'Oh, come on, mun, pull over!' he yelled. “'ou could get a fuckin' bus through there!'

Then he glanced at his terrified passengers in the rear view mirror.

'Sorry – force of habit. My uncle used to be a bus driver up the valleys. I think it rubbed off on me.'

'Did he drive for Shamrock?' Pam asked in a quiet voice.

'Aye, funnily enough he did. Tony Jones, from Porth – do you know him?'

'No, just a lucky guess – owww!'

She was thrown back into the seat as the lights changed and Ianto floored the accelerator again. He wrenched the steering wheel to the right, rocketed along the side of the museum, and brought the SUV to a screeching halt outside the Central Police Station.

'I'm never going to Oakwood Park again,' Gwen shuddered. 'That's enough white-knuckle stuff for one lifetime.'

She spotted Andy Davidson standing among a small group of officers, both uniformed and plain-clothes, milling around outside the main entrance. Crowd control barriers had been erected around the perimeter. Just outside the cordon, film crews from BBC Wales, HTV, S4C and Sky News were setting up their equipment. Gwen recognised one of the BBC journalists, and tried not to catch her eye. It would be impossible to explain the morning's events in terms that a television news audience would understand.

She pushed the door open, tucked the laptop under her arm, and gave Andy a wave. He waved back, and Gwen seized her chance to lose herself in the crowd of her former colleagues. The Doctor, Martha and Pam piled out behind her, and Jack opened his door with an audible sigh of relief. Ianto locked the vehicle and tried to look casual as a couple of traffic policemen looked daggers at him.

One of the plain-clothes officers broke away from the unofficial welcoming committee and strode towards Jack. She was a tall, slim black woman with braided long hair and a steely expression. The sight of the SUV had already ruined her day, and now her least favourite person was walking towards her. Jack smoothed down his coat and tidied his hair before extending a hand towards her.

'Detective Swanson! How lovely to see you again!' he boomed, giving her his most charming smile.

'Captain.'

She tried not to meet his eyes and shook his hand out of courtesy. He looked her up and down for a moment.

'Have you lost weight?'

'Don't start!'

The Doctor came to Jack's side and held out his hand.

'Hello, I'm the Doctor. You must be Kathy – Jack's told me all about you.'

'Oh, bloody marvellous!'

Kathy Swanson looked around at her colleagues, the exasperation in her voice clear.

'Not only do we have to put up with Torchwood – now UNIT are trying to muscle in as well.'

'I'm not with UNIT!' he protested. 'Check with UNIT Payroll if you don't believe me!' He paused for a minute. 'Actually, come to think of it, I've never been paid a penny. Martha, can you mention that to Colonel Mace when you see him?'

'That's right,'Martha chimed in. 'The Doctor just helps us out now and again. He's like – well, like a freelance consultant.'

'I hate freelance consultants,' a low voice growled.

Price stepped forward and glowered at the new arrivals.

Almost as much as I hate so-called "experts".'

'Doctor, Captain, this is Chief Superintendent Vincent Price,' Kathy announced.

Jack, Ianto and Martha chuckled at the mention of his name.

'Nice to meet you, Chief Superintendent. I'm the Doctor – freelance science consultant and alien expert, at your service.'

He winked, and even Kathy managed a reluctant smile.

Price found himself craning his neck to look up at the lanky, athletic man in front of him. He felt even more conscious than usual of his own small stature as they shook hands.

The Doctor leaned down and whispered into Price's ear, 'And don't worry – I hate hostile aliens almost as much as I hate coppers.'

He straightened up and winked at the crowd.

'Why don't we all go inside and see if we can find out what's going on? And maybe we can get some coffee, too – we had to rush off, after all!'

He took Pam's arm, put a brotherly arm around Price's shoulders, and steered them towards the doors. The others followed him without argument, and as they walked into the police station the Doctor leaned down to Pam.

'There you go,' he whispered, 'I spent yesterday in your weird world, now you can spend today in mine.'

'Oh, bloody great!' she groaned.

St Donat's Arts Centre, 9.41 a.m.

Dave Probert was well into his stride.

'We spent a fortune on typewriter ribbons and carbon paper in those days – not to mention all the time we wasted in collating, sorting, indexing, archiving and eventually securely disposing of all those documents. Meanwhile, in the real world, the space race was in full swing. We were supposed to be moving towards a brave new world, one where computers would free our lives from pointless toil and usher in a leisure society. It's only with the benefit of hindsight that we can see how wide of the mark we were.'

He selected the next slide. It showed a faceless office block with a mysterious logo at the entrance.

'This is from a TV programme called UFO,' He smiled. 'I used to watch it with my kids. It was set in the year 1980. Gerry and Sylvia Anderson presumed that by then we'd have a manned base on the Moon, a secret organisation to combat the threat of alien invasion, and the very highest of high-tech equipment, like this—'

He hit the control again. The next image showed a white-suited woman with purple hair and elaborate Cleopatra-style eye makeup, tending a wall-sized computer complete with enormous tape spools, dozens of toggle switches, coloured lights, and tiny displays. This time the laughter was prolonged. He took a step back, allowing everyone to see the full picture.

'Yes, ladies and gentlemen, that's life in the year 1980 – as seen through the very long lens of 1970.'

Karen scribbled a few shorthand symbols in her notebook and sat back again. Maybe, if she sat there long enough, Dave Probert might actually get to the point.

'That's one example of how we can miscalculate when we predict the future,' he said, selecting the next image. 'And yet, at the same time, we got remarkably close.'

His audience were looking at a picture of a uniformed man in a strange angular car, holding a telephone to his ear.

'That's also from UFO. In fact, it's from the very same episode. How is that we were able to foresee the mobile phone – but not the microchip? Why did Gerry Anderson visualise a man in a car, making a phone call, but still had a computer the size of Barry Island on the Moon?'

Karen raised her hand and immediately sensed that everyone else was staring at her. Even though it had been a rhetorical question, Probert felt as though he should acknowledge her response. He gestured to her to stand up, and Karen rose nervously to her feet. He gave her an encouraging smile.

'Karen Samuels, from the South Wales Gazette,' she said. 'Could it be because Harold Wilson had a phone in his car when he was prime minister?'

'Yes – that's exactly it!' he almost shouted.

Karen was taken aback by his reaction. He was practically jumping around on the little stage.

'Because mobile phone technology was already in place – it was just prohibitively expensive, and not freely available. Gerry Anderson wasn't predicting the future – just extrapolating it!'

He stepped into the wings for a moment and returned with a black box, about six inches square and an inch thick.

'Would you mind passing this little baby around? But please be careful – it's quite a collector's item now.'

He handed it down to the man at the end of the front row, who looked bemused. After a few moments' cursory inspection he passed it to the woman next to him. The background conversation increased in volume as the delegates examined the mysterious artefact. The square box was handed along the seats and eventually made it as far as Karen.

'Oh my God!' she exclaimed, turning it over. 'A Sinclair ZX81!'

She ran her fingers over the 'touch-sensitive' keypad, and peered at the sockets where the coax TV line-out cable and 5-pin DIN data feed from a handy cassette player would have connected to the primitive computer.

'I haven't seen one of these since I was a kid! My big brother used to have one of these,' she added, looking straight at Probert.

'Can I just ask you,' he teased, 'how much RAM did your brother have?'

'Only 16K,' Karen responded immediately. 'Our parents weren't millionaires!'

A ripple of laughter spread through the audience. Most of the delegates at the sales conference were in their late twenties or early thirties at the oldest. This piece of ancient technology meant as much to them as their grandparents' reminiscences of crystal sets and 78 rpm records.

'Yes, ladies and gentlemen, Miss Samuels' brother had a huge 16 kilobytes of Random Access Memory,' Probert said, slowly enough that the message sank in. 'And if you – or more likely, your parents – could afford it, you could upgrade it to a massive 64K. Just about as much memory as the lunar module had when humankind first landed on the Moon. Not even enough for a ringtone, in today's terms.'

He paused and called up the next image. It was an advertisement showing a man in an 18th century-style wig, leaning back from his desk with a contended expression on his face.

'This was published in an American magazine called OMNI, in the same year as the archaeological curiosity that you're looking at came onto the market,' he said casually. 'Apple had manufactured one of the very first home computers. The thrust of the marketing campaign was that if Thomas Jefferson had had a personal computer, it wouldn't have taken him six weeks to write the Declaration of Independence. He could have drafted, edited, inserted, amended, deleted, redacted, cut and pasted, revised, and eventually printed the finished version in a fraction of the time.'

He stood back and let his audience read the page laid out on the screen before them. The specifications for the computer, by 21st century standards, were rudimentary to say the least. Yet, nearly thirty years previously, this device had represented the state of the art for the general consumer market.

Karen was making copious notes – she knew instinctively that this was an important moment in history, and she was privileged to be hearing it.

'One thing struck me when I read this advert again, a few days ago. It does not mention the word 'digital' anywhere. It meant nothing to people outside the fields of electronics or computing. The only time people dipped a toe into the digital ocean was when they bought a "digital" watch. Now, even though most people still don't know what the word means in its mathematical sense, nobody is immune to the effects of the digital revolution. We've all got CD players and DVD players and Freeview boxes. We throw the words "digital information" around as casually as any other media mantra – but how many people know what it really involves?'

Immediately most of the delegates realised that their favourite buzz-phrase was little more than that. If they'd been pressed to explain the digital coding of information, the majority of them would have struggled to sketch out the basic theory.

Probert pulled up the still from UFO again. “I look at this prediction of life in 1980 again, and I laugh. Nobody ever had the vision to skip over the existing technology and imagine something completely new. Until now.'

Cardiff Central Police Station, 12.26 p.m.

In the Communications & Despatch Room, Andy, Gwen and Ianto were ploughing through the online log of emergency calls since 9.00 that morning. Kathy Swanson was watching in fascination while they collated statistics and cross-referenced reports. The Doctor and Pam leaned against the wall, aware that they were at best unwelcome guests. The door flew open and Jack burst in with Martha close behind him.

'Gwen, Ianto, are you two okay to stay here?' he demanded.

'Yeah, I suppose so,' she murmured, her eyes riveted to the laptop. 'Why? Where are you going?”

'I'm going to drop Martha at the hospital,' Jack said flatly. 'They could do with a doctor to oversee the situation. Then I'm going back to the Hub to try and find out what the hell's going on. Give me a call if you need me – this is gonna be good!'

With a dramatic flourish of his long coat he swept out of of the room, leaving everyone breathless in his wake. Jack was like a force of nature when he sensed danger. Kathy breathed a sigh of relief as the door closed behind him, and Gwen smiled to herself. She'd observed Jack and Kathy's love-hate relationship before.

'I think we've got a timeline coming together,' Ianto announced, looking up. 'We recorded a short burst of Rift activity at 2011 last night. Just a tiny blip – not enough to register on our regular equipment. I've had to go down to nano wavelengths for this. The first reports came through about fourteen hours later. If it is the Rift, it's nothing we've ever seen before.'

The Doctor looked embarrassed.

Ah! That was probably me, plugging the TARDIS in.'

Everyone turned to him with accusatory expressions.

'That was about the time you legged it from the pub,' Pam agreed.

'Okay, scrub that!' Ianto shrugged. 'We haven't got Rift activity. Not a sausage.'

'So, whatever's causing this,' Gwen added, 'it's home-grown.'

Pam had her mobile phone in her hand, and was pressing keys rapidly with her thumb.

“Haven't you got better things to do than send a text?” the Doctor asked.

'Well, I can't very well send a fucking postcard, can I? They've all vanished!' she retorted. She handed him the handset with a smug smile. 'Mobile internet. Cardiff University's website. Have a look at this.'

The Doctor peered at the screen for a few moments and laughed out loud.

'Pam, I think you might have just found us our first lead.'

He slipped his arm around her shoulder and led her over to a large laminated map of South Wales on the far wall.

'Fancy playing detective for an hour?'

'Yeah, why not?'

'Andy, how long does it take to get to St Donat's?'

Andy looked at him in bemusement.

'I dunno. Twenty minutes, half an hour, depending on the traffic.'

'We need to speak to this guy – right now!'

He leapt to his feet and pulled Pam across the room, almost knocking Kathy over in his haste to talk to Price.

'Sorry, we need a lift – I hope you don't mind, but my transport's off the road at the moment.'

Price nodded mutely, not sure what he was agreeing to. The Doctor wrenched the door open and placed one hand on the frame, looking back into the room with a huge smile.

'Andy, start the car, we'll meet you out the front. Set the controls for the heart of St Donat's! First person to see the sea gets an choc-ice! Allons-y!'

Next Episode