Still, she can't have got far let's go and find her -' said Jamie.

He was about to run out through the open doorway, but the Doctor grabbed him by the shoulders.

'No, Jamie!... Those images you and Zoe saw on the scanner were obviously put there deliberately to tempt you outside.'

'Eh? By who?'

'I don't know... But there's somebody or something out there that wants us to come out of the TARDIS...

Tempting us to step outside time and s.p.a.ce!'

'You think it's a deliberate trap?' Jamie asked.

'I think it's incredibly cunning and dangerous and in a way I've been expecting it. As I tried to tell Zoe ' He was interrupted by a warning bleep, and a red light began to flash on the console at first slowly, but gradually accelerating.

'That's the first warning... The emergency unit is running out there isn't much time left.'

'Time for what?'

'To make our getaway. We have to move on, Jamie.'

'But what about Zoe? We can't just leave her out there...

' Jamie made up his mind, and with a sudden lunge, he wriggled out of the Doctor's grasp. 'I'm going after her.'

He made a dive for the open doors, and was instantly swallowed up in the dead white nothingness beyond. 'No, Jamie come back '

The Doctor started to follow him, torn this way and that by conflicting fears and anxieties. He knew he couldn't desert his two companions but at the same moment another red light went on, emitting a bright steady glow, while a second bleeper produced a shrill, sharp note.

'Oh, no the second warning... '

Distracted, he hurried back to the console and as he did so, he heard another sound, more terrifying than anything that had gone before.

It was both high-pitched and deafening: it seemed to be splitting his skull open and the frequency of the signal was more like a vibration than a sound. His whole body shook in spasms of uncontrollable pain, and he clapped his hands over his ears.

He looked wildly around the Control Room; the noise was so overpowering, he expected to see a physical presence there but the enemy, whatever it might be, was still invisible.

'Who are you?' he gasped. 'Where are you? What do you want from me?'

His legs would not support him any longer. Under overwhelming pressure, he staggered and almost fell, but managed to clutch at his armchair and flopped into it.

His eyes bulged, and the veins stood out at his throat and temples he looked as if a multiple G force was clawing at him; his skin stretched tight, showing every muscle and sinew.

Only his lips moved, as he whispered over and over again, to himself: ' Fight... I must fight... I will fight... Fight... I must fight... I will fight... ' '

2.

The Power of Thought.

The Doctor sat bolt upright remembering.

With his eyes closed, he turned his head restlessly from side to side, feeling once more the unbearable pain that racked his entire body...

' I will will fight... ' he repeated in a hoa.r.s.e whisper. fight... ' he repeated in a hoa.r.s.e whisper.

The sound of his own words penetrated the confusion in his brain, and he awoke completely, opening his eyes.

Darkness. Silence. An all-encircling blackness.

He remembered now where he was... Or rather, he remembered that he didn't know where he was. He was sitting with his back against the tree that didn't smell like a tree, in pitch darkness; and he had been trying to piece together the events that led up to this moment in time.

But was he in time at all? Was he in s.p.a.ce? Was this, in fact, the vast and terrifying nothingness that had entrapped the TARDIS perhaps for ever?

If only he had never plugged in the emergency unit that took them for a brief period outside time, s.p.a.ce and reality itself. That was when it had all started going wrong... And once it began to go wrong, it continued from bad to worse.

He tried to recall what had happened next, after Jamie and Zoe left the TARDIS, and that horrific sound-vibration had overpowered him.

Power... That was it... A stronger power that he couldn't resist, and yet he knew he had to. He had to fight back with the only power left to him the power of thought.

He had hung on to that last hope, as tightly as he had clung to the arms of his chair, feeling himself about to be drowned in a torrent of sound and terror and pain aware that at some deeper level the battle was being fought for the possession of his mind.

Something was trying to conquer his mind and he struggled desperately against it.

He remembered forcing his brain to work to keep it ticking over to keep on resisting. He even found himself reciting multiplication tables: anything to keep his mind working independently, and shut out the alien force that was trying to invade him.

'Four fours are sixteen... Five fives are twenty-five... Six sixes are ' He faltered for a split second and the pain increased at once 'Ah! thirty-six, of course... Seven sevens are forty-nine...

He drove himself on, concentrating on the pure perfection of arithmetic, and by the time he had got to eleven times eleven, the pain and the noise had begun to subside.

'Twelve twelves are a hundred and forty-four,' he said defiantly, to whatsoever or whomsoever might be listening... But n.o.body was listening to him now.

The vibration had stopped: all was silence.

He took a deep breath. So far, so good. The first battle was over.

Now all he had to do was to find Zoe and Jamie.

They had gone outside the TARDIS, into that endless white s.p.a.ce just as he now sat here under an invisible tree somewhere in endless darkness. He cudgelled his exhausted brain, trying to recall what had happened next...

Zoe wandered hopelessly in a world of white: white beneath her feet, white above her head, white all around her. It was like being alone in an arctic landscape, but a landscape with no land or sky, and no horizon. Nothing but white. Under her feet the floor stretched on for ever white and shining, like a blank sheet of paper.

She called out in a thin, tremulous voice: 'Jamie.. ?

Doctor ! Where are you?'

But her words didn't even echo. They sounded flat and dead, and she knew in her heart of hearts that no-one could hear her.

She wished she had never left the TARDIS. This wasn't the magical City that she loved this wasn't her home. The Doctor had been right... This was nowhere.

Then she stopped roaming aimlessly, and stood quite still.

Was that really a sound, penetrating the empty silence, or had she imagined it? She listened hard, and far away she heard a faint, familiar voice: ' Zoe! Where are you? Zoe! Where are you? ' '

'Jamie!'

With a gulp of relief she began to run towards the source of the sound and a moment later she saw Jamie rushing to meet her. She flung her arms around him. 'Oh, Jamie I've never been so glad to see anyone in my whole life! I thought I was lost for good.'

He hugged her, encouragingly.

'I thought you were, too. I'm glad I found you.'

'This is a terrible place... It's not the City it's not Scotland either.'

'No, I know... And it's not even a mist like we thought.'

'Just opaque nothingness... Like the Doctor said.'

Jamie frowned. 'Aye he said to me this was all '

He changed his mind. No point in scaring the poor wee la.s.sie any more; she'd had enough of a fright already.

'What? What did he say to you?' she wanted to know.

'Nothing much. That can wait.' He looked around and shivered. 'This place doesn't feel right; it gives me the shivers. Come on, let's get back to the TARDIS.'

Holding her hand, he began to lead the way.

Somehow, it was very unnerving, walking towards nothing. Surely he should be able to see the TARDIS from here? If he walked back the way that he'd come, he must find it... If this was the way he'd come.

He stopped, looking left and right. Zoe glanced up at him quickly: 'You're sure this is the way?'

'Oh, yes, this must be the way I... ' He cleared his throat, and began again. 'No, well, you may be right, it's possible that... '

He headed in a different direction, then stopped again.

Zoe hung on to him, gripping his hand very tightly.

'We're lost, aren't we?' she said.

'Och, no, I wouldn't say that... We just um well... '

'Well what?'

He didn't finish his sentence, but set off yet again, this time taking a completely different course. After a few more steps, he gave up.

'You know something?' he asked, with a cheerful grin that did not reflect his inner feelings in the very least.

'What?'

'I think we're lost!' he retorted, as if it were a great joke.

Zoe did not smile. She said quickly: 'This isn't funny, Jamie.'

'No you're right it isn't. And that's what the Doctor tried to tell me... He said we'd walked into some sort of trap.'

'What do you mean?'

'He said those pictures we saw on the scanner were meant to tempt us out here... It was a deliberate plan. You saw your home I saw mine the very things we couldn't resist. Like as if we were fishes, and someone was baiting a hook to catch us... Those pictures we saw were the bait and we swallowed it!'

Zoe shuddered: 'Don't!... But if something were trying to lure us out here what is it? And where is it?'

Now it was Jamie's turn to repress a shiver. 'Aye well let's not be in too much of a hurry to find out, eh?'

They looked at each other in despair, and Zoe asked: 'What are we going to do?'

Jamie scratched his head. 'We've got to make contact with the Doctor, somehow. The TARDIS can't be all that far away I only left it a few minutes ago.'

'How do you know?' Zoe demanded.

Jamie stared at her. 'What are you saying? I only just ran out of the TARDIS, not more than three or four minutes since '

'But you can't be sure of that. Remember we're outside time as well as s.p.a.ce. There's no such thing as minutes any more. The TARDIS might be aeons away for all we know.'

Jamie realised that she could well be right, but he refused to accept it. Once they started thinking like that, they might as well give up hope altogether. 'Rubbish!' he scoffed. 'I tell you, the TARDIS is only just around the corner '

'What corner? There aren't any corners.'

'You know what I mean! Anyway, I'm going to yell for help, and I suggest you do the same!' He cupped his hands to his mouth, and shouted: 'Doctor Doctor! Can you hear us?... Doctor Doctor!'

But at that moment the Doctor was still sitting in his armchair, locked in a life-and-death struggle with an unseen force for the power of his mind.

' Doctor Doctor Doctor Doctor!'

The voices of Zoe and Jamie came through faintly high and clear but the Doctor could not break his concentration. The veins on his forehead stood out fiercely as he repeated the same words over and over again: ' I must I must fight... I will fight... fight... I will fight... ' '

Lost in infinite whiteness, Zoe and Jamie plodded on, still calling, but with less and less hope of being heard. Finally Zoe refused to go any further.

'For all we know, we could be walking away from the TARDIS, instead of going towards it! Or else we might be wandering round in circles.'