'You really think they're telling the truth?' said Rose. 'About the force field, and why they need humans and everything?'

'Wouldn't be at all surprised.' The Doctor pressed a b.u.t.ton, bringing the door into sharp relief. 'After all, no one's going to suspect it's true for a second. And even if they did, even if some human sat down to play this game and thought, "Hang on, maybe these are real aliens telling us about their real enemies," what are they gonna do about it? Try to tell anyone and they'd get locked up, trust me.'

'And I suppose no one on Earth would even care,' said Rose, thinking about it. 'What a bunch of aliens get up to on their own planet is hardly going to bother anyone.'

On the television, the first puzzle filled the screen. It was different to the mathematical one from last time the Doctor had played the game, but he solved it just as quickly. Once inside, he had to climb through vents, jump across chasms, and negotiate twisting and turning mazes.

'I can see why those fat porcupines couldn't manage this,' commented Rose, as the Doctor pressed a combination of b.u.t.tons to navigate a series of long jumps on to tiny platforms. 'These are definitely meant for jumping insects.'

A couple of Mantodeans appeared at the end of a tunnel. The Doctor, leaning forward eagerly, pressed down hard on the controller's blue b.u.t.ton. An icon appeared on the screen, a tiny pistol. 'Gun selected,' the graphics read. The Doctor's finger hovered over the red b.u.t.ton.

Rose caught at his arm. 'You can't! You can't shoot them! They're real! You'd be killing them.'

The Doctor hurriedly pressed another b.u.t.ton, and the Mantodeans snapped out of view as he ducked down a side tunnel. He sat back, looked at her. 'I was getting a bit carried away there.'

She gave him a half*smile. 'Yeah, me too. I mean, I wanted you to shoot them, for a second. Kill or be killed, and all that.'

He nodded. 'Only it isn't, you're right. Even if I have to start again, half an hour here or there probably won't make much difference to Mickey.'

She hadn't thought of that, and frowned. But although she'd have gunned down a dozen aliens to get to a Mickey being threatened in front of her, this was different. If the Doctor was right, he was just being made to play video games somewhere. Who knew, they might even be providing him with tea and biscuits. 'Have you got far to go, do you think?' she said. 'Before you get to the end of the game, I mean.'

'I'm not going to get to the end of the game,' he said, surprising her.

'What, is it too tricky?' She couldn't believe that was the case.

He laughed. 'As if!' Then he continued more seriously, 'We reckon I got further than any other player in a shorter time, right?'

'Right.' She nodded.

'And we reckon that's why they took Mickey. Probably because they thought he was their great hope, the only person likely to get to the end of the game. If what they're saying is true, they only need one person to get to the centre of this place, one person to activate their disruptor. Then that's it, game over. I do that, they'll have no need to come looking for me, they'll have achieved their purpose.' He gave her a meaningful look. 'And they'll have no need for Mickey any more, either.'

She understood, and shivered a little. 'Yeah, I get it.'

'So I'm just going to beat my previous score, and then I'm going to stop. And then they'll come and get me. And ' he broke off for a moment to jab at the controller 'that's probably going to be any minute now.'

The Doctor's fingers flickered over the b.u.t.tons, and then stopped. He gave a loud sigh, and placed the controller down on the table. 'There. One hundred points higher. Should get their attention.'

She felt like a bundle of nerves. Knowing a giant porcupine might appear out of thin air any second wasn't a relaxing thought. 'And what do we do when we get there?' she asked. 'What's the plan?'

'Ah,' he said. 'Probably should have checked you were up for it, really. You are up for it, aren't you? Dangerous, and all that.'

'Up for what?' He could be frustrating sometimes. 'But of course I am. You know I am. Always.'

He grinned. 'Yeah, I know that. Well, you'd better get behind this chair then.'

She glared at him. 'If you think I'm hiding while you run off into goodness knows what...'

'No, no, no,' he said hastily. 'Just, if they see both of us, they'll capture both of us, right? So they have to just see me, then there's one of us free to let the other out. Grab my ankle, then the teleportation field should take you as well. They won't be expecting someone else the other end. With any luck you'll be able to crawl away before they notice you.'

She was aghast. 'That's the brilliant plan?'

He held out his hands. 'It'll work! Those thick necks they've got, they won't be able to look down properly. You'll be way out of their field of vision.'

She wasn't convinced, but knew she probably couldn't come up with a better plan in time. 'Couldn't you be the one hiding?' she asked as a last resort.

'I'm over six foot!' he said. 'Catch me fitting behind this.' He patted the chair. 'And the shame of it! Hiding behind a chair from a monster? Me?'

Rose raised her eyebrows at him, but got up anyway, and crawled into the gap between the seat and the wall. The Doctor arranged a throw so it was more or less covering her. 'Oh, gross!' she called out. 'No one's hoovered back here since the Dark Ages.' A second later: 'I've just found a biscuit.' A second later: 'I've just found a pound coin.' A second later, worriedly: 'I don't know what I've just found, but I've put my elbow right in it...'

And a second later, she could smell something. A tang in the air, as if she'd just been spritzed with lemon juice. Her tongue and nostrils were fizzing.

'This is it,' said the Doctor, perching on the arm of the chair above her. 'Hold tight.'

She grabbed hold of his bony ankle, reflecting in a distracted way how odd it was that a 900*year*old alien from outer s.p.a.ce wore diamond*print socks, just like they'd used to sell at the shop where she'd worked, 8.99 for three pairs, breathable cotton weave.

There was a crash; they'd smashed open the front door again. And then the Doctor was standing up, and saying really unconvincingly, 'Oh no! Why are you pointing a gun at me? I'll come quietly.'

And she just had time to see, from under the draped throw, a pair of clawed legs obscuring her view of the screen, which was showing a load of angry Mantodeans swarming around, clacking their jaws together.

'Game over,' Rose thought, and then everything disappeared.

SIX.

Rose was disorientated for a few seconds, and because of that she almost died. She felt sick and dizzy, and her skin tingled as if she'd just had a bath of Alka*Seltzer. She didn't think she'd ever be able to move again, or even know quite how bits of her body attached to other bits of her body ever again. But as her head began to clear she suddenly became aware that her arms were moving. She certainly hadn't consciously decided to move them, and she observed the strange phenomenon with detached interest for a few moments. Then the mental mists parted still further, and she realised that her arms were moving because she was clutching something with a death grip, and it was trying to shake her off. A moment later and she recognised it as an ankle, as the Doctor's ankle, and everything came flooding back. The Doctor was talking loudly, trying to distract attention from her. 'Where am I? What's all this about then?'

She unclenched her fingers, let go of the ankle. There were other ankles in her line of vision, squat ankles covered in coa.r.s.e black hair, leading to ugly clawed feet. A Quevvil's feet. Trying not to make a sound, not to move, she took in her surroundings. She was on a concrete floor, utterly exposed. But to one side was a litter of things: filing cabinets, chairs, a cracked computer monitor. She wriggled over to the pile as quickly and quietly as possible, began to slither behind it. Her legs were still sticking out when a door opened right next to her and she heard the tink tink tink tink of more claws on concrete. Lots more claws. Had she taken a fraction of a second longer to recover... of more claws on concrete. Lots more claws. Had she taken a fraction of a second longer to recover...

Not that she had recovered fully she still felt nauseous and she found herself mentally checking herself, trying to work out if she'd been rea.s.sembled in exactly the right way. Had her fingers always been that long? Had her feet always been so small? She finally concluded that they had.

She wondered where they were. Still on Earth, she reckoned, thank goodness she couldn't believe that any alien planet populated by giant porcupines would feature old computer chairs and doors with Chubb locks. And as Jackie had said, this was only a local promotion well, let's hope they'd not ventured outside of London for their secret base, if that was where she was.

Through a gap in the junk, she could just see the protesting Doctor being bundled through a door on the other side of the room. She heard a yell of surprise in Mickey's voice before the door slammed shut and felt a huge sense of relief. He was alive.

After a few minutes, the Quevvil who'd taken the Doctor into the room came out, alone. The key was turned in the lock. Rose mouthed a silent sigh of thanks she'd been worried that they'd shut them in with some hideous alien lock, like the ones on the prize booth, and she'd never be able to let them out.

Mind you... how was she going to let them out anyway? There were four Quevvils in the room with her, and there was no way she could get over to the door without them seeing her, however low on the ground she kept. She'd just have to hope they left. But they were gazing at a couple of monitor screens, seemingly transfixed. On the screens, she could see complex 3D graphics. She suspected they were plans of this Mantodean stronghold they wanted infiltrated, and perhaps were representing the gaming progress of the Doctor and Mickey. But she couldn't see how how exactly it made no sense to her. exactly it made no sense to her.

She waited, and waited, trying to gently flex her muscles so her legs didn't go to sleep in case she had to make a quick getaway. If it came to it, there was always the other door, the one the Quevvils had come through she hadn't heard a key turn in the lock.

The minutes crept slowly by. If only she had a way to distract them! But she just couldn't think of one, not one that'd keep them distracted for long enough, anyway. The Quevvils weren't even talking, she wasn't even learning stuff about the enemy, they were just staring at these screens. But then...

Something must have happened, something to do with the game. All four of the Quevvils leaned forwards, muttering among themselves, pointing and commenting. Was this it? Was this enough of a distraction? No, it wasn't, there was still no way she could get to the locked door, but but she could try for the other door.

The thought was barely in her mind before she'd acted; if she'd waited it might have been too late. She was on her feet, turning the handle, slipping out of the gap... She pulled the door to behind her and sprinted off, still silently, waiting for the shouts and the gunfire and the pursuit, any moment now, any moment...

But they didn't come. She'd made it!

She'd abandoned the Doctor and Mickey to their fates, but she'd she'd made it... made it...

No, that was being silly, this was all part of the plan. She couldn't distract the Quevvils while she was in the room, but she might find something out here. And at the very least, she'd have found an escape route for when she did did get them out... get them out...

She looked around her. She was in a corridor lit with dim electric bulbs. There was another door, and there was a ladder leading up to a trapdoor in the ceiling.

She shinned up the ladder, but the trapdoor was protected with the dreaded hideous alien locks. Mentally crossing her fingers, she climbed back down and hurried over to the door at the far end. It was locked, but with an ordinary key. She turned it, still trying to be as quiet as possible, and slipped through. She took the key; locked the door behind her.

She almost sneezed as the must hit her nose. Piles of mouldy old newspapers and magazines tied up with string lined the walls; she left the door open for the light from the corridor and took a closer look, managing to discern, through the dust, 1970s copies of Woman's Realm Woman's Realm ('knit a Rupert the Bear for a favourite grandchild') and the ('knit a Rupert the Bear for a favourite grandchild') and the Daily Telegraph Daily Telegraph ('Nixon resigns'). Every step she made showed in the dust on the floor, and she felt like Neil Armstrong. Didn't they say that footsteps remained on the moon for ever, because there was no wind to disperse them? Perhaps one day the Doctor would take her there, and she could see for herself. ('Nixon resigns'). Every step she made showed in the dust on the floor, and she felt like Neil Armstrong. Didn't they say that footsteps remained on the moon for ever, because there was no wind to disperse them? Perhaps one day the Doctor would take her there, and she could see for herself.

If they made it through this, that was.

On the other side of the room there were concrete steps, leading up to a door, with a thin sliver of light underneath. Daylight? She made her way up. The door was locked. She squinted through the keyhole, but couldn't see a thing. It had to be blocked by a key.

So... she could think of only one plan. It came solely from children's books, the adventures of the sort of young detectives who caught smugglers and jewel thieves, and she couldn't believe it would work in real life, but she had to give it a go.

She collected an aged, crackling Woman's Realm Woman's Realm, and after a search discovered an ancient children's comic with its free gift of a lollipop still sellotaped to the cover. Trying not to think what damage the sweet would do to a child's insides after thirty years, she prised the sticky mess away from its long*term home, and climbed back up the steps. She shoved the magazine under the door, rammed the lolly stick into the lock, took a deep breath, crossed her fingers and pushed pushed.

There was a dull thud on the other side. Trying not to get her hopes up too high, she pulled back the magazine.

And there, on top of a recipe for damson jam, was the key.

She was shaking as she put it in the lock. So close, so close... If they heard her now...

The door didn't want to open. It creaked like a door from a horror film. She expected the Quevvils to come running; she expected to find Dracula waiting for her on the other side.

But, to her amazement, she came out somewhere that she actually knew knew. It was the newsagent's shop where the Doctor had bought his seventeen Guardians Guardians; where she'd bought that last pint of milk, now in Mickey's fridge; where she'd totally failed to win on the scratchcards.

She considered briefly that the newsagent was in league with the aliens, but she couldn't see it somehow. He might be a bit grumpy, but he wasn't that bad. And the door into the shop obviously hadn't been opened for ages.

Luckily, no one seemed to have noticed her come in. The newsagent was serving a customer at the front of the shop, and he couldn't have heard the door opening over the loud background Radio One.

She slipped out of the front door, on to the street. There in front of her was the prize booth, the place that they'd totally failed to get into before. The Quevvils had obviously extended it down, linked it up with some of the old shop cellars. A nice little underground base that no one'd suspect.

But now what could she do?

She looked down the high street for inspiration. Woolworths. Chemist's. Chippie. She couldn't half fancy a portion of chips, swimming in salt and vinegar...

Something clicked, somewhere at the back of her mind. Something she'd once read, or seen on one of those Wildlife on One Wildlife on One doc.u.mentaries. Porcupines and salt. Porcupines would do anything for salt; they were like total salt addicts. Would it be too much to hope yes, it would be, it would be far too much to hope that these creatures had the same craving, just because they looked like the Earth animal... But they doc.u.mentaries. Porcupines and salt. Porcupines would do anything for salt; they were like total salt addicts. Would it be too much to hope yes, it would be, it would be far too much to hope that these creatures had the same craving, just because they looked like the Earth animal... But they might might do, and it was the best plan she had... do, and it was the best plan she had...

She nipped into the chip shop. The smell was divine, but all she had was the pound coin she'd picked up from behind Mickey's chair; she couldn't afford to treat herself. But there was no one else in the shop, no one to create a distraction.

'Portion of chips, please,' she said. 'Wrapped.'

The pretty Chinese girl behind the counter slid a shovelful of golden*brown chips on to some paper. 'Salt and vinegar?' she asked.

'I'll do them myself,' said Rose, picking up the giant salt pot. 'Oh, and could I get a can of c.o.ke?' She pointed to the fridge behind the counter, and the girl turned. And the instant she did, Rose was out of the door, salt cellar in hand, regretfully leaving the chips behind her. She waited for the girl to shout out, but it never came. Perhaps customers did runners all the time. It wasn't as if she'd nicked the chips. The girl might not have noticed the absence of the salt. It was the second time that day that Rose had been a minor criminal. But, after all, she was potentially saving the world.

Now came the next part of her plan, the part that relied totally on luck. Because if this bit didn't work, she might have to turn criminal for real, to get her hands on a winning scratchcard. But before that, she'd give it a go. She pulled the pound coin out of her jeans pocket, and strode back into the newsagent's.

'A hundred penny sweets, please,' she said.

Rose's fifty*eighth card was the lucky one. She was getting pretty fed up with scratching off the silver stuff only to find the inappropriately jolly message, 'Sorry, you've not won this time! Please try again!' She'd 'please try again'ed until she thought her fingernail was nearly worn down to the bone.

But here it was. Here was the winning card. She'd won a games console.

Rose hurried across to the prize booth. There was no queue. She placed her card in the slot, and after a few moments' delay the door opened up. She went in. Inside was a counter, and behind it was a Quevvil, its mouth twisted in what might have been meant to be a friendly smile. 'Congratulations!' it said. 'You have won! I will fetch your prize.'

It moved away from the counter, and Rose leaned over to look. There was a tiny room behind it, with another door at the back and on the floor, a trapdoor. That was it! That must be the entrance to the corridor under the ground! Time for the final phase of her plan if only it worked...

She stepped back from the counter, trying to keep as far away from it as possible. Then she removed the giant salt shaker, and sprinkled a tiny bit on the floor.

The reaction was almost instantaneous. It was much, much more than she'd hoped for. The Quevvil began sniffing. It raised its nose in the air like an ugly, spiny Bisto kid. Then it darted forwards, scrabbling over the counter, ungainly and desperate. As the creature sank to the floor, its black tongue darting out to lick up the treat, Rose followed its route in reverse, diving over the counter into the little room beyond. She tried the trapdoor, but it seemed locked from this side as well, and she didn't have time to experiment. So she upended the salt container, and scattered it all over the floor, making sure that some of it trickled down the sides of the trapdoor. And then she ran out of the far door, offering up thanks that the alien locks must only work from the outside, and she didn't have to make her way back past the maddened Quevvil scrabbling on the floor. She slammed the door behind her, and, ignoring the interested looks from pa.s.sers*by, hurried back across to the newsagent's.

'Look, I've only got a limited number of them cards,' the newsagent said. 'If you're going to do that again, you can just buzz off somewhere else.'

Rose gave the man her most charming smile. 'Just browsing,' she said. She waited till he was once more distracted with a customer and then, praying he didn't have CCTV installed, nipped back through the door to the cellar.

She opened the door to the corridor and peered through the gap. Her plan was working! Boy, those giant porcupines must really love their salt. All four Quevvils were on the ground below the trapdoor, licking at the floor like thirsty puppies. As she watched, one of them got to its feet and started climbing awkwardly up the ladder, then the others followed. She couldn't see what the first one did to open the hatch, but open it he did. All four climbed through, and before it was shut again, she could hear an explosion of snuffling sounds from above, as the rest of the salt bounty was discovered.

The instant the trapdoor was shut, Rose moved. She gazed up as she reached it, but had no idea how to activate the alien lock. She gave the ladder a quick tug, but it was bolted too firmly to the wall. She had to keep the Quevvils at bay for as long as possible, though... She plunged her hands into her pockets, looking for inspiration. She couldn't afford to waste time... Only one thing occurred and she did it as quickly as possible, before hurrying into the first room, the one they'd teleported into. She locked the door behind her, not that it would keep out a determined Quevvil for long. Then she darted across to the other door, and turned the key. She opened the door, and there was the Doctor, and there was Mickey, tied to a couple of plastic chairs, playing the game.

'Surprise!' she called.

They both turned, enormous grins on their faces. 'What kept you?' said the Doctor.

SEVEN.

Rose made as if to shut the door again, trapping the Doctor and Mickey in the Quevvils' bas.e.m.e.nt once more. 'A bit of grat.i.tude, please, or the rescue stops here and now,' she said, but she was grinning as broadly as they were.

'I take back everything I was saying about humans being useless,' said the Doctor.

'When were you saying that?' asked Rose, indignantly.

Mickey sighed. 'Oh, 'bout every other minute for the last hour.'

Rose glanced at her watch. It had taken her some time to effect the rescue. But better late than never. She moved over to them and began working on their bonds, Mickey first. Her instinct had been to release the Doctor first, and although that was just a perfectly natural choice, didn't mean a thing, somebody had to be first, she had an idea Mickey would take it more personally than that. And because she didn't want to admit that he would be right to do so, she'd changed her plan.