'Shock at discovering he was only part of a whole?'

'Exactly. Dreadful thing to find out. It would undermine your whole sense of identity.' The Doctor bent, hands on knees, so that his eyes were level with Chiltern's. 'I'm not sure I can even hypnotise him in this state. Let's see. Dr Chiltern,' he called softly, 'it's the Doctor. Will you come here? Look at me, please. Just look at me, yes, like that, like the night in the cab, remember? You wanted me to help you then. Now I need you to help me. Will you? I think you can. Will you try? It's safe here. Nothing can harm you. Will you come and talk to me?'

As if from far away, life and expression seeped back into Chiltern's face. Entranced but alert, he looked at the Doctor, who smiled in relief and greeting. 'You're here. Good. Thank you.' He stood upright. 'He's still in there,' he said happily.

'Very nice, I'm sure,' said Sabbath. 'Now if he only knows something useful.'

'Dr Chiltern, will you answer a question for me?'

'Yes.'

'Aside from the residences in London and on Dartmoor, did Sebastian or any other member of your family have any other home? Any place to go to in order to hide, or rest?'

'I don't know.'

'Try hard to remember. Please.'

Chiltern was quiet for a minute. 'There were... moors,' he said finally. 'The piles of stone... The house... The house was cold...'

'Yes. But was there any other place?'

Another silence. Then: 'I don't know.'

'Are you certain?'

'I don't know.'

The Doctor grimaced and turned away.

'It can't be Yorkshire or any other moor,' Sabbath pointed out. 'They have no tors.'

'No. He's thinking of here.' The Doctor looked sombre. 'Only of here,' he repeated under his breath.

As they returned downstairs, Sabbath said casually, 'Why don't we take a walk?'

The Doctor nodded. 'All right.'

They went down into the town orchard and along beside the shallow, amber-coloured river. The sun was bright without being too hot, and the sky a soft blue with only a few wisps of cloud. Butterflies flitted among the fruit trees. The Doctor kept holding up a finger for one to land on and then examining it.

'Red Admiral,' he observed as a particularly handsome pair of wings fluttered away.

Sabbath was uninterested in lepidoptery. 'Can she really see the future?'

'Sometimes.'

'Then it doesn't look very promising.'

'Her reaction could have been to some vision having only to do with her.'

'That was a very interesting conversation you had.'

'In what way?'

'In the way she claimed you were responsible for her present condition.' The Doctor strolled on without answering, his eyes following the butterflies. 'Well?'

'I'm sorry. Was I supposed to say something?'

'Don't be coy with me, Doctor,' Sabbath rumbled.

'I wouldn't dream of it. What do you want to know? Why I had such an effect on her? I have no idea.'

'None?'

'None at all.'

'I find that difficult to countenance.'

'Really? I can spin you all sorts of plausible-sounding nonsense theories if you like. Such as, I am some kind of temporal strange attractor.'

'Is that true?'

'How should I know?' said the Doctor impatiently. 'It's not something you can test in a lab. Am I a time-sensitive? Yes. Do I biologically incorporate certain temporal elements? Yes. Does that sometimes appear to cause odd things to happen? Yes. Do I know what any of it means? No.'

'You are being disingenuous, Doctor. Have you honestly taken no notice of the way in which coincidence trails you like a shadow?'

The Doctor shrugged. 'Anecdotal evidence. You can't draw any conclusions from it.'

'No?'

'You've got that tone in your voice again. That sly, "the Doctor is an intrinsically disruptive force who must have Something Done About Him" tone.'

'You claim such righteousness in your protection of time. Are you afraid to face the possibility that you might be one of its greatest threats?'

The Doctor snorted in amusement. 'Are you willing to face the possibility that your thesis might be a trifle self-serving?'

'In the sense that it supports my argument, certainly.'

'Which argument is that again? I know we discussed it in Spain, but I was a bit woozy '

'Doubtless from all the popping around in time you do. You're as dangerous as that fool Chiltern meddling with his toy time machine.'

The Doctor stopped, stung. 'That's a ridiculous accusation.'

'Is it?'

'Overblown and, if I may say so, a tad hysterical. I am hardly shredding time.'

'No, but you're fracturing it. Showing up here, showing up there and each time a new timeline branches off.'

The Doctor scooped a stone from the bank and tossed it lightly into the river. With a soft splash it vanished, leaving gently spreading concentric circles. 'Oops. Fractured the water.'

'Facile and specious,' said Sabbath. 'There is no correlation.'

The Doctor had sought out a few more smooth stones. Now, as they continued walking, he began to juggle them. 'Your problem, Sabbath, is that you're a reductionist. You're so certain a timeline can be pinned down and defined just so. It's a very eighteenth-century view of science, if you don't mind my pointing that out, this idea that truth is something that can be proved rather than something that hasn't yet been disproved. Is there some ideal timeline out there, some Platonic essence of form, that you're trying to make time conform to?'

'Dear me, Doctor, I can't believe I'm hearing you argue for chaos.'

'You think it's either your kind of order or else it's chaos.' The Doctor started juggling so that he caught stones behind his back as well as in front of him. 'What's so difficult to understand about variations within a structure? What if the "real" timeline is like a musical score, with infinite ornamentations possible? There can't be a perfectly correct performance of a score, because a score is a guide, not a definition. It opens possibilities rather than closing them off. Why shouldn't time be like music?'

'Very pretty. And what if you're wrong, and every trip you so blithely take pulls out another thread in time's warp?'

The Doctor caught his stones one after another, and tossed them all into the river. Their various concentric ripples smacked lightly together and dissipated.

'And what if you're wrong, and in paring down time's possibilities you strangle reality?'

'Doctor!'

They both turned. It was Fitz's voice.

'Down here!' called the Doctor.

Fitz came jogging through the trees. 'Telegram came.'

He handed it to the Doctor, who ripped it open. Fitz and Sabbath looked over his shoulders and they all three read that neither Mayview nor anyone else at the clinic knew of or could find records for any other residences Chiltern might have owned or rented.

'That's it,' Sabbath said quietly. 'We have exhausted all our leads. Unless the local police track him down, a contingency I consider remote, Dr Chiltern has eluded us.' The Doctor said nothing, just stared at the telegram as if it might, if he looked long enough, turn out to contain a different message.

'Maybe he won't use the machine again,' said Fitz without much conviction.

The Doctor shook his head. 'If he didn't intend to use it, why take it with him?'

'Indeed,' Sabbath agreed. 'And it's possible that if he even so much as tinkers with it...'

The Doctor crushed the telegram into a ball.

Chapter Nineteen.

The Doctor and Sabbath sat up late that night. Fitz, who was the last of the others to remain downstairs, sat nursing a beer at the little bar and watching them across the room, their chairs drawn up to the stone fireplace, heads together, arguing, pondering, suggesting. He was struck by the disinterested concentration of their discussions, as if each had forgot who the other was and was focused solely on the problem. Periodically the Doctor would rise and pace restlessly, while Sabbath, with a deep sigh, leaned back in his chair and stared morosely at the flames. Then the Doctor would resume his seat and they'd confer some more. The Doctor had drawn dozens of the machine's details and instructions on a pad, and they went over these again and again without, so far as Fitz could make out, arriving at any helpful conclusions. They were brooding separately when he finally went upstairs to bed.

'Of course, if by any chance he uses the machine again without destroying the universe,' Sabbath said drily, 'he'll show up on my instruments and we can quickly find him.'

'Ah yes,' said the Doctor in the same tone. 'After all, he's used it three times already and the universe is still here. We shall continue to trust to blind luck and it will see us through. But in that case,' he added, 'shouldn't you be crouched over your tracking screen?'

Sabbath displayed a small black device that resembled a telephone pager. 'This will alert me as soon as there's any disturbance.'

'Very efficient.'

'I think so.'

They sat staring into the fire for a while.

'You realise that all this proves my point,' said Sabbath.

'Well, thank goodness. I'd hate to think the end of the universe did nobody good. What point is that?'

'Your misplaced sentimentality about humanity's intrinsic value and their right to free will. This misguided fool got hold of a time machine, and where are we? Where are all his innocent fellows, those people whose welfare you claim to care about?'

'What are you arguing? That if somehow you'd managed to murder Chiltern before he found the machine, everything would be fine? Someone else would have found and understood it sooner or later.'

'Exactly. They can't be trusted.'

'That silly Prometheus. Nobody told him.'

'The gods did,' Sabbath murmured. 'Afterwards.'

'As I recall, it was his liver that was torn out, not his heart.'

'Such arrogance, Doctor.'

The Doctor shrugged. 'Obviously in this argument I stand in for Prometheus. Just as you stand in for the gods.'

'Touche. But you haven't rebutted my argument.'

'Which is what? That humanity is fundamentally base and needs to be controlled? That a democratic society with civil liberties is a society with social inequality and crime, whereas a police state, by silencing dissidents, can guarantee a rough egalitarianism and public safety so that the poet's freedom to be subversive is invariably bought by the suffering of the poor? That the rule of the people too easily becomes the rule of the mob? That the centre of every human being is self-interest and even virtue is corrupt? That they are animals whose moral sense degenerates as soon as their bellies aren't full? That idealism has killed as many as viciousness and there is no philosophy, however noble, that can't be turned to depraved ends? That people will always fear, and as long as they fear they will hate?'

'There is ample evidence for the truth of everything you've just said. History makes my case for me. Can you, in all intellectual honesty, deny it?'

'No.'

'Then why?' said Sabbath, genuinely puzzled. 'You're not stupid about these matters. You're not starry-eyed, or basically impractical. You can see what reality is. Why don't you accept it?'

The Doctor was sitting back in his chair, his clasped hands resting against his chest. 'Because I prefer not to.'

'I beg your pardon?'

'Because I don't, won't accept. I don't approve. Injustice is the rule, but I want justice. Suffering is the rule, but I want to end it. Despair accords with reality, but I insist on hope. I don't accept it because it is unacceptable unacceptable. I say no.'

'It's all about what you you want,' said Sabbath softly. 'You won't accept the way things actually are because it is your will that they be different.' want,' said Sabbath softly. 'You won't accept the way things actually are because it is your will that they be different.'

The Doctor looked at the fire. 'Perhaps.'

'There's no "perhaps" about it. You continue to amaze me, Doctor. This hubris is breathtaking.'