'Your pilot's ready to leave,' said Chris.

The Doctor decided to ask later. They clambered up the ladder into the shuttle. The Doctor shut the airlock and the ship immediately lifted off, throwing them against a wall. It was a moment before the stabilizers cut in.

The shuttle was small, c.o.c.kpit, lounge area, facilities and storage. The Doctor ran forward. Roz was glaring at the controls, hands moving fast. 'They've launched an interceptor,' she said.

'They're going to shoot us down?'

'No. It'll just use force fields to suck us into its cargo bay. It's three times as fast as we are.'

'Keep going maybe we'll think of something,' said the Doctor. He leant heavily on the door frame. The changes had stopped, at least. Or they were so subtle now he wasn't noticing.

'I don't believe it,' said Roz. 'That interceptor just changed course. It's heading away from us. Look.'

The Doctor checked the tactical screen. 'There's nothing on its course,' he said. 'It's chasing a ghost.'

'Your doing?' said Roz.

He shook his head. 'Thank you, Lady Genevieve,' he said.

The Doctor and Chris stared at each other.

The Model Citizen Model Citizen was a standard, comfortable shuttle design was a standard, comfortable shuttle design c.o.c.kpit, a cabin like a lounge, a kitchen and facilities. There were 267 six seats, in rows beneath the windows, facing one another across the cabin.

The Doctor and Chris sat opposite each other and stared.

'It's good to see you again,' said the Pontifex Saecularis, at last.

'When did you last see me?' the Doctor asked, cautiously.

'Nine no, ten years ago,' said Chris. 'In subjective time, anyway.' He looked down. 'Look, there's no easy way to say this. You died. On Yemaya.'

The Doctor nodded. 'The story had a different ending.' He held up a hand. 'Don't bother with how. It doesn't matter. We only have a few minutes anyway.'

The c.o.c.kpit door slid open, the pilot standing in the doorway.

'Roslyn!' said the Pontifex. 'I didn't dare believe it.'

She took a good, long look at him. He was surprised how much that look could rattle him, even after all these years.

'Nice boots,' she said.

'Thanks,' he said. 'Lady Forrester you are the Lady Roslyn Forrester?'

Roz stared. 'Not exactly. I knew I couldn't let you two out of my sight without something something happening.' happening.'

'There's a second Nexus in the solar system,' said the Doctor.

Roz listened to the Time Lord, but she wouldn't take her eyes off Chris. The Pontifex found himself shifting in his seat like a nervous schoolboy.

The Doctor had taken out his abacus, muttering to himself.

'They have control of it. But not real control, not full control.'

Chris nodded. 'Or they wouldn't have needed to interrogate us.

They could have just whisked us out of existence.' He made a gesture with his hand. 'Whoosh, and we're gone.'

The Doctor looked at him. 'And they certainly wouldn't have chosen this particular Chris out of all the possibilities.'

'How'd you make Pontifex?' Roz wanted to know.

'I'm carrying SLEEPY around in my temporal lobe,' said Chris. He felt her horror even before her expression changed.

'I'm ludicrously telepathic. Don't worry, I'm not reading your mind. I don't bother unless I need to.'

'Like when you're questioning a criminal,' said Roz. 'I see.'

268.

'I wonder what they told Walid,' Chris said.

'The same thing they told Armand,' said the Doctor. 'That they had a weapon, or a tool, depending on how you look at it, capable of altering reality.'

'So they kidnapped you two to demonstrate it?' said Roz.

'No,' said the Doctor. 'Walid left in a hurry just after we were taken prisoner. Ah.' He beamed at the abacus. 'I think I know just where.'

'You can't be certain until the conjunction ends,' said Chris.

'No. But I have a pretty good idea.' The Doctor turned to Roz.

'You were supposed to run for it at the first sign of trouble,' he said sternly.

'Be real,' said Roz. 'I'd have been a cloud of expanding vapour the moment they got a lock on me.'

'They had what they wanted. Why waste ammunition on a low-ranking pilot?'

'Maybe. They're ignoring us right now, and I'll just bet you two know why.'

'Genevieve,' said Chris. 'She used her security access codes to confuse and disable part of the security systems. And then there's me. Doctor, there are only ninety seconds left in the conjunction.'

'What's that mean?' demanded Roz.

'It means I can't keep up this telepathic screen much longer,'

said Chris. 'When it drops, we're going to appear on a lot of screens. Despite the confusion on the ground, there are at least three pursuit ships in our vicinity.'

'There's something I'd like to try,' said the Doctor.

Chris read what he wanted right off the surface of his conscious thoughts. 'd.a.m.n, that's devious. All right. But just a moment.'

Chris got up. He found himself crossing the tiny amount of s.p.a.ce between them. Roz just stared at him and he folded her up in his arms and kissed her.

He wasn't sure, given the parameters of this reality, whether it was the appropriate thing to do. Given the way she was holding the hair at the back of his neck, he still wasn't sure.

'It's been a long time, Lady Forrester,' he said.

'I'll go program the computer for evasive manoeuvres, then, shall I?' she said hoa.r.s.ely, and fled to the c.o.c.kpit.

269.

Chris sat back down. 'Jack White killed her,' he said, very softly.

'Fifty seconds,' said the Doctor.

The Doctor and Chris reached across the narrow cabin, sitting forward in their seats until their hands met. They grasped each other's hands tightly. The Doctor bowed his head, almost as if he was in prayer.

'Thirty seconds,' said the Pontifex. 'I hope this works.'

'Anything could happen,' said the Doctor. 'History's out of control.'

'The Nexus,' said Chris.

'No,' said the Doctor. 'Just the usual chaos.'

Chris felt the conjunction drop away. It was like letting go of your grip on a window ledge. He felt something pa.s.s over and through him, anchoring itself even as he fell. He grabbed at the Doctor's hands, grabbed at his mind, tried to find something to hold on to.

'Let go!' the Doctor cried out. Let go! Let go!

If you suddenly had never existed, would you know you'd ever lived?

Some questions were too hard to answer. He let go.

'We'll be in Ionian s.p.a.ce in ten minutes,' Roz shouted. She'd left the c.o.c.kpit door open so the Doctor could hear her. 'How is he? Back to normal, OK?'

The Doctor looked up from Chris. The young man was lying on the seat under the window, looking ordinary and rather pale in his servant's uniform, muttering about lemmings and Uruguay.

'He'll be all right,' he called out. 'Containing mult.i.tudes is an exhausting exercise.'

'Good, good,' called Roz.

The Doctor got up and stood in the door of the tiny c.o.c.kpit.

Callisto was a spotty brown ball ahead.

'I wish you could wake him up,' said Roz. 'We could use an experienced pilot.' She brushed her fingers across one of the screens. The Doctor saw two points of light, a red line indicating their current course. 'I think they're going to intercept us. I'm not sure. One thing I am sure about this ship was never meant for 270 tactical manoeuvres. If they catch us, it's two tanks and a school bus.'

The Doctor's eyes went to another screen. It showed a TopTenPercent media report. Explosions, seen from orbit, ugly blossoms in a patchwork atmosphere, blue, brown, red. It was so important that Roz was watching it while they were escaping.

'What's happened?'

'Someone's dropped a comet on Purgatory,' she said.

'The Imperial Landsknechte training planet,' breathed the Doctor. 'It's started.'

'It's not Walid,' said Roz. 'Why drop a bomb on your own troops?'

'Unless the Landsknechte have gone rogue. If they challenged him...'

'Maybe. There's been nothing like that on the news. More to the point, why bomb their school? It's not a strategic target.'

'It's a warning,' said the Doctor. 'This could be you.'

'It must be Armand,' said Roz.

There was an awkward silence.

It was broken when the communicator bleeped. 'Oh s.h.i.t,' said Roz. 'Wish me luck.'

The Doctor stepped back out of range of the screen. He heard voices from the c.o.c.kpit as he sat down to watch the news.

Purgatory had been hit by a comet dropped into its atmosphere.

It was a bizarre world, composed of great hexagonal slices of other people's planets, dozens of ecologies. The better to train the Landsknechte to go out and blow them up.

The comet had been mostly ice. It had melted as it struck the atmosphere, chunks of rock exploding out of its core. They had rained down all over the training world. Casualties were down in the tens of thousands there weren't more than a few hundred thousand troopers on Purgatory at any given time.

This could be you.

It was war.

In the c.o.c.kpit, Roz yelled, 'Yeah, and I happen to be the newly appointed Pontifex Saecularis, which means I'm your bosses'

worst nightmare. Turn your a.r.s.e around and go back to Io!'

A moment later, she appeared in the doorway. 'That worked.'

271.

'I thought the job didn't begin for a month,' said the Doctor.

'It's been all over the media,' said Roz. 'I told them I'd taken the pair of you prisoner, and it was a jurisdictional problem.'

The Doctor looked at her. 'And is it?' he said.

Roz leant in the doorway, looking at him.

'You might be asked to choose sides, Roz. Very soon,' he told her. 'Do you want my advice?'