He crashed to the ground with Olvir on top of him.

They rolled apart, winded. Olvir was feeling sick and dizzy at this, his second hand-out of abuse, but he struggled to his knees. If only he wasn't too late. He had to get Nyssa away from the danger of the radiation field.

But Nyssa was no longer there.

Olvir stared mutely at the chain and the straps that had secured her. They swung gently in the deadly light. He made it onto his feet. There was no sign of the Garm, either, and no clue as to where they might have gone. His burner had come to rest close to the reactor globe too close for safety. He'd have to reach into the hottest part of the danger area in order to reach it.

'I wouldn't,' Valgard said from behind him. 'The radiation would kill you.'

Olvir turned. Valgard was still on the floor where he'd fallen, but he'd managed to prop himself up. He said, 'Get much closer and you're dead, unless you can get to a decontamination unit.'

'You're lying.'

Valgard shrugged. 'Go ahead, then. In my day we had better training.'

'What are you talking about?'

'You're a raider, aren't you? Combat trained.

Colonel Periera, was it? The one they call the Chief?'

Olvir tried not to let his surprise show, but it was unavoidable. He said, 'How do you know?'

Valgard shifted a little in an attempt to make the most of the strength that he had left. 'I recognise the moves,' he said. 'He taught the same ones to me. I was with him for five tours until he turned me in for the reward.' He shook his head, and smiled at the memory. 'I was lining up to do the same to him, but he beat me to it. Good times.'

'How did you get here?'

'We're slave labour, all of us. That's how the Terminus works.'

'Where are the guards?'

Valgard almost laughed. 'Don't need them. If we don't work, there's no Hydromel for us.' He put out a hand. 'Help me up,' he said, but there was a whining note in his voice that caused Olvir to step back a little further.

'Come on,' Valgard said, 'Look at me. I'm a danger to n.o.body. I'm finished and I'm dying.'

But Olvir wasn't to be won around. He said, 'Where did that thing take Nyssa?'

'Who?'

'The girl. Where did it take her?'

'I don't know. This is the first time I've ever been into the zone.'

'Will he harm her?'

'He's supposed to be helping her to get cured.

That's what he's here for.'

Olvir glanced across at the straps and chains. They'd stopped swinging. If this was Valgard's idea of a healing process, he'd got it badly wrong. Was it worth even attempting to find Nyssa if she was doomed anyway?

He said, 'How can this be expected to cure anybody?'

'Help me, and I'll show you.' Valgard was just a little too eager in his offer. Olvir didn't believe that the Vanir knew any more about the inner workings of the Terminus than he did.

Olvir said, 'I'll find her myself.' The Garm hadn't pa.s.sed them as they'd fought, so that limited the choice of directions. Olvir took a guess and moved off.

'Don't leave me,' Valgard called after him.

One of the tactical principles of the Chief's combat training programme was that no enemy should be left alive if there was a possibility that he could pose a future threat. Olvir obviously thought that Valgard was finished and not worth the attention... which was what Valgard had wanted him to think.

As soon as he was sure that Olvir had gone, the Vanir scrambled to his feet. He wasn't fast, but he was a long way from being the helpless invalid that he'd pretended to be as long as the young raider was around. He got his staff and went over to the reactor globe, approaching in such a way that he was out of the direct line of the radiation. The staff was his protection as he used it to draw Olvir's burner out of the danger area.

His time in the zone might be getting short, but he had a weapon. Let them try to stop him now!

'Are you all right?' Tegan said anxiously, and Turlough fanned some of the acrid smoke away. His attempts to pull down some of the shielding in the newly uncovered section of the underfloor area had started a small electrical fire, but it had quickly burned itself out.

'I'm all right,' Turlough a.s.sured her.

'I might be able to help you if you'd tell me what you're trying to do.'

'There was some kind of radiation leak around here, remember? It gets worse when the motors are running. That's when the door to the TARDIS is fully materialised... that leak must be the engine signature that the emergency programme attached itself to.' And as if to prove a point, Turlough leaned back and started to kick at the cladding which lined the underfloor tunnel. There were sparks and more smoke, but pieces of the cladding came away.

Tegan looked up. On the wall behind her, a faint ghost-image of the door to the TARDIS was starting to appear. She was about to tell Turlough, but the liner's automated warning voice beat her to it.

' Primary ignition is now beginning Primary ignition is now beginning,' it boomed down the corridors. ' All systems running on test. Departure All systems running on test. Departure sequence is beginning now. sequence is beginning now. ' '

'What's happening?' Tegan said.

'I should think that's obvious. The liner's getting ready to leave.'

'But we can't leave yet!'

The liner was deaf to any argument that Tegan might offer it. ' All drones to designated a.s.sembly points All drones to designated a.s.sembly points,' it went on, ' Countdown to secondary ignition follows. Countdown to secondary ignition follows. ' '

Turlough heaved himself half-way back to corridor level, and he looked at the results of his work with some satisfaction. He estimated that the door was about one-third materialised. Tegan was no longer looking; she was more concerned about their imminent departure. They were already separated from the Doctor and Nyssa, and it was a situation that threatened to become permanent.

'The ship's on automatic,' Turlough told her.

'There's nothing you can do.'

'But I've got to try,' she said, and before he could argue any further she'd set off towards the control room.

She covered the distance in record time. As she ran, the decks beneath her feet began to rumble with the buildup of launch power. Coming into the command area stopped her short for a moment. It was a room peopled by busy ghosts, ranks of empty seats before which controls were setting themselves and read-outs were displaying to no purpose. But Tegan knew that all of this activity was only secondary, a reflection of the orders that were being issued by the automatic command centre at the forward end of the room.

' Departure sequence is now under way, Departure sequence is now under way, ' the box announced calmly. ' ' the box announced calmly. ' Countdown to docking disengagement Countdown to docking disengagement is now beginning. Preparing to blow clamps and withdraw all is now beginning. Preparing to blow clamps and withdraw all lines. lines. ' '

She began to look for some main control or master switch, but there was nothing. 'Can anyone hear me?'

she said, knowing that she was wasting her time. 'You must stop.'

' Countdown to primary burn is now under way. Countdown to primary burn is now under way. ' The deck was almost shaking. ' The deck was almost shaking.

' Test mode on all systems is disengaged, all systems Test mode on all systems is disengaged, all systems operating within permitted tolerances. operating within permitted tolerances. ' '

'Can't you shut up!' Tegan yelled in frustration, and she slammed her fist down on top of the automatics.

The control box shut up.

Tegan couldn't believe it. An alarm started ringing somewhere, and a call of Emergency! Launch abort Emergency! Launch abort was echoing around the rest of the liner, and several lights on the control console had died whilst others were blinking furiously. was echoing around the rest of the liner, and several lights on the control console had died whilst others were blinking furiously.

She ran back to tell Turlough. For the first time since they'd arrived, it was starting to look as if the whole messy adventure might be brought to a safe conclusion.

The floor panel was still open, but the door to the TARDIS had faded again. And it seemed that Turlough had gone with it.

The rise in engine power prior to the aborted launch had given Turlough the opportunity he needed. The underfloor leak had intensified, the door had become solid, and Turlough had wasted no time in going through. He made straight for the console room, and he set his communication cube down by the master control.

' The Doctor still lives. The Doctor still lives. ' There was no expression in the voice. ' There was no expression in the voice.

'He's powerless,' Turlough said, 'He's trapped, he's probably dead already.' He did his best to sound confident, but he could see too late that it wasn't coming through.

It would have made no difference, anyway. The Black Guardian's voice was dark with anger. ' You You represent a poor investment of my time and energy, represent a poor investment of my time and energy, ' it said, and the brightness of the cube began to increase. ' ' it said, and the brightness of the cube began to increase. ' There There is only one course to follow with such an investment. is only one course to follow with such an investment. ' '

Without warning, the cube escalated to peak brightness. The energy explosion that followed was like that of a bottled sun breaking free.

The Doctor hadn't been having much success with the main control handle of the Terminus. He took off his jacket and tried to force it from every angle, but there seemed to be no way of moving it. Kari tried when he became exhausted, and then they combined their strength and pushed together. The only movement that the handle made was in the direction that had already been programmed in.

'Why won't it move?' Kari demanded, exasperated, as they took a couple of minutes to get their breath back.

'It's computer-controlled,' the Doctor said. He was about to add something else, but he didn't; instead, he looked over the console as if he was seeing it in the light of a new idea.

Kari knew better than to interrupt. After a few moments, the Doctor said, 'The technology here is phenomenal.'

'I don't understand why it's still functional after all this time.'

The Doctor tapped the console, thoughtfully. 'Have you heard of a timeslip?'

'No. What is it?'

'Something that can happen if you try to make a jump through time without any adequate form of control. At least, that's the theory. You arrive with your timescale way out of alignment with your surroundings; subjective time seems normal, but it's pa.s.sing much more slowly in relation to everything else.'

'You mean... the whole Terminus is on slow time?'

'A neat way of putting it. Yes, that's more or less what I mean. What we're witnessing is probably a high-speed emergency programme to deal with an unstable engine except that it's taken several hundred years to get this far.

Kari shook her head. 'This is madness.'

'If I'm right, the time differential will make it impossible to move that lever. It would take the strength of a giant.'

'A giant?' Kati said, and their eyes met as they both had the same realisation. There was a giant already around. He took the Lazars off into the forbidden zone.

Olvir, meanwhile, had found the Garm.

Unfortunately, he seemed to have found it too late.

The beast was empty-handed, and there was no sign of Nyssa anywhere. Olvir wasn't sure how best to deal with it. Intimidation was probably a waste of time, as he'd found when he failed even to sting it with his burner and he didn't have the weapon anyway, so it was all rather academic.

He knew that it could understand at least a few rudimentary commands. Furthermore, he was wearing enough of his Vanir armour to look as if he was ent.i.tled to exercise authority. He decided to give it a try.

He stepped from the shadows before the Garm, and his nerve almost failed him. The dark beast seemed to fill the pa.s.sageway, and the glowing coals that were its eyes gazed down on him and their message seemed to be, I see through you, little man I see through you, little man.

'I'm unarmed,' Olvir said quickly, showing his hands. The Garm stopped. Olvir added, uncertainly, 'Can you understand me?'

'Perfectly,' the Garm said.

The voice was a shock. An inhuman, ba.s.s-magnified whisper, it seemed to come, not from the Garm, but from all around the Terminus itself. In spite of the strangeness, there was an unexpectedly gentle quality.

'Why are you doing this?' Olvir said. 'Why are you torturing people?'

'I drive the disease from them. All would die, but many survive.'