The Doctor shrugged unapologetically. Sabbath smiled.

'I hesitate to mention it, but you haven't yet thanked me for saving your life. Again. That's three times.'

The Doctor eyed him sardonically. 'Once unwillingly.'

'Nonetheless.'

'You're right, the result's the same. Make it three. Thank you.'

'Think nothing of it. Doctor?'

The Doctor had abruptly stood up. For a few seconds he only stared blankly ahead of him, lips slightly parted, then, with a blink, he noticed Sabbath again. 'Excuse me,' he muttered distractedly. 'There's something I need to attend to.' He hurried from the room.

Once upstairs, Fitz had discovered he didn't really feel like sleeping. He'd leaned out of the window, smoking, staring at the thatch-roofed houses, so still under the moon. Dreaming through the apocalypse. The Doctor had that end-ofthe-universe tension about him, no doubt about it. It was difficult to imagine in this tiny, peaceful place. Fitz was used to the end of the universe looming amidst a lot of noise and action and big machines, and even then it had never been a concept he could actually grasp, any more than he could conceive of the number one billion. Now it suddenly struck him that he might not make it to the age of forty, and for some reason that notion was more chilling than any of his past near-brushes with death.

A shadow moved in the street below. Fitz craned out and identified it. 'Doctor!' he called softly.

The Doctor looked up, moonlight flattening his eyes.

'Where're you going, then? No, wait, hang on.' Fitz stubbed his cigarette on the sill and hurried from his room.

The Doctor eyed him unwelcomingly, but Fitz didn't care if he didn't want company. He He wanted company. And he wouldn't mind knowing what was going on either. 'Where are you off to?' wanted company. And he wouldn't mind knowing what was going on either. 'Where are you off to?'

'I thought I'd take a walk on the moor.'

'I'd think you'd had enough of it after last night.'

The Doctor moved off without replying. Fitz fell in with him.

'So,' he said, 'what are we looking at? The end of the universe?'

'Only as we know it.'

'Oh, so that's all right then.'

They walked in silence past the church and up the narrow road that led to the moor.

'So how will it be,' said Fitz after a while, 'this end of which you have spoken?'

'Well, put simply, a chain reaction will start and time will get all shredded up.'

'That's the layman's version.'

'Yes. I can give you the mathematics if you like.'

Fitz glanced at the Doctor, but apparently he had spoken without irony. 'That's all right.'

They walked on.

'We're lucky it hasn't happened already,' the Doctor said at last.

'Yeah? Well then, it might not happen for a while.'

'Your point being...?'

'Well, that's better than happening next instant, isn't it? Gives you some time.'

'To do what exactly?'

'Erm, what you always do. Fix things. Pull the impossible rabbit out of the non-existent hat.'

The Doctor smiled faintly; it didn't reach his eyes. They passed an ancient stone cross, its arms weathered to nubs, and turned left down an even narrower track through some woods.

'Seriously,' said Fitz, following the Doctor through the darkness, 'can't you pitch a spanner in the thing?'

'I have to find it first.'

'Can't you track its time disruptions signal or whatever?'

'Only if it's on. And if it's on '

' we're off. Got you. So you don't have any idea where it is?'

'Given Victorian transportation limits, it's probably still in the British Isles at this point, but that's not much help.'

'This third Chiltern... He's not right, is he? I mean, physically. So he'd have to go some place he could hide.'

'Yes. I'm fairly positive he's fled to some other place that he owns or feels he has safe access to. But there's no record of such a place in his personal or professional files at the clinic, or in any of the papers at the house here. Miss Jane and Millie never heard Sebastian mention anything of the sort, and Nathaniel doesn't know of one, either because there isn't one or because he lacks the full memory and knowledge that Sebastian had.'

'So only Sebastian could tell us.'

'Yes.'

'Except he's dead.'

'Yes,' said the Doctor. The word came out strangely, a long sigh. They were out of the trees now and Fitz looked at him sharply, but, in profile at least, his face was without expression.

'You could try Chief Ironwing,' Fitz said lightly.

The Doctor actually laughed. 'Miss Jane is a multiple personality with some telepathic abilities and occasional clairvoyant flashes. She doesn't actually talk to the dead. Just as well. The poor woman has enough problems.'

'What about the other mirror? The one Scale had? If that were in the machine, would it work better?'

'Better as a time machine, yes. It could still be hideously destructive to this continuum.'

'You mean it can't be used at all?'

'I dare say it would work all right in the vortex.'

They had come to the edge of a high field overlooking the moon-shadowed moor. The Doctor pointed to the crags of a massive tor off to the left. 'I'm going over there.'

'All that way?'

'You don't have to come.' The Doctor started down. Fitz sighed and followed.

It was very quiet, quieter than anything Fitz had ever experienced in the countryside in the twentieth century, not that he'd spent much time there. Occasionally an owl hooted, or some other nightbird called. Panicked rustles in the bracken indicated they'd startled a rabbit. The Doctor walked quickly, his hands in his pockets, as if he had some purpose in mind, though Fitz couldn't imagine what that would be. But he felt obscurely that he ought to stick with him. Watch his back, so to speak.

In fact... Fitz stopped and turned, but saw nothing. Hadn't he heard something? Another step besides his own and the Doctor's? But the only sound was the faint stir of the wind in the bracken. Embarrassed at his jumpiness, he hurried to catch the Doctor, who had strode obliviously ahead. Probably lost in his thoughts, which, if you were the Doctor, was a big place to get lost in. Watching his back, literally the set shoulders and stiff spine Fitz was suddenly sure of something. He increased his pace till they were side by side.

'You've got a plan.'

The Doctor didn't look round. 'Have I?'

'A cunning plan.'

The Doctor smiled that faint, distant smile. 'A fiendish plan.'

'You have, haven't you?'

The Doctor sighed, and Fitz was suddenly sure of something else, something he'd rather not be sure of.

'I'm not going to like it, am I?'

The Doctor didn't answer, only increased his pace. They were walking up the base of the tor, weaving among the rocks. 'What is it?'

'Fitz...' said the Doctor.

There was a helpless note in his voice that struck Fitz cold. He grabbed the Doctor's arm, spun him around. 'What is it!' The Doctor's face was bleak as the stones around them. Fitz let go of him, and he immediately turned and walked away.

'Wait,' said Fitz. 'Don't.' But he didn't know what he was asking. He ran to catch up again. The Doctor waited for him on a grassy plateau. Fitz stopped beside him, catching his breath. The Doctor was gazing at the moor, stretched serenely below them in the moonlight. Fitz gave it a desultory glance.

'Feels funny admiring the view when the world's going to end.'

'It's still beautiful,' the Doctor said matter-offactly. 'Look down no, on the ground, beneath our feet.' Fitz looked. 'Do you see it?'

Faint scars seemed to mar the grass. Looking more closely, Fitz saw stone remains, worn level with the ground, forming a barely discernable circle.

'Iron Age,' said the Doctor. 'This was once a village. Time,' he added vaguely. 'Things come and go.'

'Bit banal,' said Fitz. He was still uneasy and a little angry. The Doctor shrugged.

'Well,' he said, equally vaguely. 'Language...'

He sat on a broad flat stone and after a moment Fitz sat beside him. The piled heights of the tor rose darkly behind them, an ogre's castle.

'Sabbath is dangerous,' said the Doctor.

'You know, I'd gathered that.'

'I'm serious,' the Doctor snapped. 'He's finally deigned to tell me in full about his theory of time, and it's lunatic.'

'You mean really wrong? I didn't think he was stupid.'

'Not entirely wrong, but idiotically mis-applied. He believes...' The Doctor trailed off, eyes still on the moor. 'Well, it's complicated, but essentially what he believes, if applied practically, would be ruinous for the web of time.'

'Well,' said Fitz carefully, 'that's a bit academic, isn't it? I mean, we've already got one whopping great threat to the web of time to deal with. Seems to me Sabbath has to join the queue.'

The Doctor waved a hand impatiently. 'He has to be dealt with, Fitz.'

'Not if the universe comes apart, being as he'll come apart too. Not to mention us. Don't you think you have enough to worry '

'Dealt with! Do you understand what I mean?'

Fitz stared at the set, white profile. He's lost it, he thought. The strain's made him bonkers. Because the Doctor would never suggest what the Doctor seems to be suggesting. He stood up.

'Let's go back.' The Doctor didn't respond. 'Seriously, it's late. It'll be dawn soon. You need some rest.'

The Doctor glared at him. 'Don't patronise me, Fitz.'

'I'm not, I just '

'I'm staying here. Go if you want. In fact, go. Leave me alone.'

'I'm not going without you.'

'Really? You're going to force me to come?' The Doctor looked at him with an expression Fitz had never seen before. 'Do I have to remind you how easily I could break any bone in your body?'

'Jesus,' said Fitz in disgust. 'You've gone off the rails, you have.'

The Doctor shrugged, turning back to the moor. 'As you say, considering that the universe is going to end soon, it hardly matters. Go away. Now!' he added when Fitz didn't move.

'Forget it.' Fitz plonked down on an adjacent rock. 'You're looping around like a pair of waltzing mice and I'm not leaving you like this. You want to break a bone, OK, pick one. As long as it's not in my fingering hand.'

The Doctor glared at him, but there was something else in his face as well. Suddenly, to Fitz's surprise, he smiled the old smile, warm and rueful. He shook his head. 'I should have known better.'

'Yeah,' said Fitz shortly, 'maybe you should.'

'Fitz,' the Doctor's voice was milder now, almost gentle, 'I need to he by myself for a bit. To think some things through. Go back to the inn. Get a little sleep.' He squinted at the horizon. 'I think you're right about the dawn. It will be morning in a few hours. Come back then if you like.' Fitz hesitated. 'Please.'

Fitz stood up but still hesitated. 'What if that dog's still about?' he said lamely.

'The police found and shot it. The latest theory is that it killed Chiltern and O'Keagh. Sabbath told me.'

'Did you mean all that about Sabbath?'

'He is very dangerous,' said the Doctor slowly, 'and he must be stopped. Let's not talk about it any more now. Please leave. I just need an hour or two.'