'This is very interesting,' the Doctor said, 'but...'

Bor didn't seem to hear. He was looking at his sc.r.a.pheap again. 'That one'll go next. The crack's always been there, but the leak's been getting worse. I didn't find out why until I followed the control cables.'

Valgard was thinking that he'd heard enough.

He'd been standing in the shadows at the end of the row for most of the conversation, and any doubts that he may have had were now gone. Not that it mattered; the object of the exercise was to return from the zone with evidence that he'd carried out his unwelcome job so that he could watch Eirak wriggle and squirm and try to get out of the bet that he'd made. He probably had no intention of carrying out his part of the bargain, in which case Valgard was going to see to it that his authority in the Terminus would be ended forever. If you couldn't believe his promises, why believe in his threats anymore?

For now, speed was the main problem. Valgard needed to get back as quickly as possible to minimise the effects of the zone and give himself the best chance of fighting them off. He was running on the effects of a Hydromel high, brought on by the use of more than half of the drug remaining from his last issue. What remained couldn't keep him going for much longer.

He stepped out into the light. 'Tell them nothing, Bor!' he shouted. 'They're company spies!'

Bor's expression changed in an instant. 'You're from the company?' he said, horrified. 'You seemed so friendly!'

The Doctor and Kari both stood. 'They've got great respect for their employers,' the Doctor observed.

Valgard stepped out for a closer look at Bor. It was the first view he'd had of Bor's condition. 'You've been torturing him!' he accused.

'Have they?' Bor said. 'I can't remember...'

Valgard was still advancing on them, his staff held crosswise. As they both remembered, he could use it to good effect. Kari brought her burner around, but Valgard wasn't to be fooled.

'You've no power for that,' he said. 'I was there when you found out, remember?'

Valgard kept on coming. He changed his grip on the staff, holding it out to full length and sweeping it from side to side. 'I'm taking you back for Eirak to see,' he said.

'Fine,' the Doctor said, 'Let's go. There's no need for violence.'

'That comes later. When we've finished questioning you.'

'Ah. I see. In that case...'

He seemed to be about to turn away at least, that's how Valgard read it, which was what the Doctor had intended. On the next sweep of the staff he turned suddenly and caught the end with both hands.

For a moment, it was stalemate. With no central pivot to give the staff leverage, they were in a contest of strength, a contest that the Doctor won.

Valgard was whipped aside. The weight of his own armour kept him going, and he spun into the junk that Bor had heaped before the cracked reactor globe.

With an almost deafening sound, the junk came down with Valgard sprawling in the middle of it.

'My wall!' Bor shouted in agony as he got to his feet, but he was drowned out by Valgard's screams as a beam of unchecked radiance burst from the globe.

Valgard rolled aside. Bor arrived and, again using his arm to shield his face, attempted to pile some of it back.

'Well done,' Kari said approvingly, but the Doctor could get no pleasure from the victory.

'He's not as strong as he looks,' he said. 'Let's go.'

They turned to leave, but it wasn't going to be so easy. The darkness that blocked their way was huge and powerful, and its eyes glowed a dull red.

Force of habit had Kari reaching for her useless burner. 'What is it?' she said.

The ma.s.sive beast was unmoving. Valgard had recovered sufficiently to prop himself up, and he said, 'You ought to know. Your people brought it here.'

'We weren't sent by the company,' the Doctor said.

He was beginning to get irritated at the persistence of Valgard's misunderstanding.

It lifted one immense paw. It took them a moment to realise that it was pointing at Bor.

'It wants something,' Kari said, although she couldn't make out what.

'It wants Bor,' Valgard said from the floor. 'It's been ordered to find him and take him back.'

'Let it pa.s.s,' the Doctor suggested to Kari. Slowly, cautiously, they moved aside. The Garm moved towards Bor. For all its size, it moved in total silence.

'Look at that skin,' the Doctor said as it pa.s.sed them.

'Like natural armour.'

Kari tried to make it out. The Garm just seemed to soak up the light. 'Radiation-resistant?' she said.

'A purpose-built slave to work in the danger area.'

The Garm raised Bor from the floor as if he weighed no more than a handful of paper. Bor hung there limply, without the strength to fight or resist. But then as he was turning, the Garm stopped.

n.o.body really heard it, but they all felt it: a deep stirring that was beyond sound and almost beyond sensation. 'Subsonics,' the Doctor said, adding as the Garm moved out with Bor, 'obviously some kind of signal.'

A moment later, and the beast was gone.

Kari looked at Valgard. He stared back defiantly, although he still didn't seem able to make it up from the floor. She said, 'What about him?'

'Leave him,' the Doctor said.

'I should kill him.'

'He's too weak to follow us. Come on.'

The Doctor set out with some obvious sense of purpose. He was scanning the walls and the open latticework of the ceiling above. She had to catch up before she could ask, 'What are you looking for?'

'Control lines,' the Doctor explained, but when he glanced at Kari she was looking blank. 'The ones that Bor said he followed.'

Contrary to Eirak's hopes, Nyssa had been giving them a hard time.

She'd already made one attempt to run as they'd escorted her to the storeyard, and but for the fact that she turned into a blind alley between two fuel tanks, they'd have lost her. Sigurd cursed himself and kept a tight grip on her from then on. Some day soon Eirak might be selecting someone else to lose his Hydromel supply, and Sigurd didn't want to be the next in line.

They had a procedure for tethering rebellious Lazars in the storeyard, although it was more often used for those who were dazed and liable to wander if not watched. Sigurd warned his companion to hold onto Nyssa as he set off the subsonic signal and then prepared the manacle that would lock her to the supporting strut until the Garm arrived. When he turned around, his companion was on the floor and Nyssa was running again.

She wasn't at her best, but neither were they.

Sickness slowed her, and heavy armour slowed them.

The gap widened as she ran for the tarpaulin and ducked under. Almost immediately, Nyssa bounced back with the breath knocked out of her.

The Vanir with whom she'd collided helped them to bring her back, but for the moment she had no fight left. They lifted her and closed the self-adjusting pressure catch of the manacle around her wrist, and only then did Sigurd release his hold on her. Two bad moments like that were enough to ruin anybody's day.

He signalled his thanks to the Vanir who had helped.

'Who's team are you on,' he said, 'Gylfi's?'

The Vanir inclined his head in agreement, but further conversation was prevented as Sigurd's companion called for their attention.

'It's Bor!' he said. 'The Garm found Bor!'

The Garm came striding from the Terminus with Bor held out before. They ran to the yellow line to receive him, and when the Garm had been relieved of the body he stepped back to wait.

Bor was lowered to the floor. 'Most kind,' he was mumbling, 'most kind...'

'The armour's ruined,' Sigurd's companion observed. The Vanir who had arrived in time to help with the capture of Nyssa stayed well back.

Sigurd said, 'We'd better get him to Eirak while he can still talk. Otherwise they'll think we stole the best parts.'

Looking at Bor now, it was difficult to see why anybody should want his armour but Sigurd was taking no chances. He undid Bor's makeshift sling and they each got an arm around their shoulders to carry him away, feet dragging along the floor. 'Stay and watch her,' he said to the other Vanir as they pa.s.sed, and a few seconds later they were gone.

The Garm was still waiting. The Vanir turned to Nyssa and said, 'Let's see that chain.'

He reached for the manacle. Nyssa tried to push him away with her free hand. It wasn't what he was expecting. He took a surprised pace back, and then he quickly removed his radiation helmet.

'It's me, Nyssa!' Olvir said.

When he'd realised what was happening he'd tried to follow and rescue her from the drone, but by that time she was already being handed over to the Vanir.

He'd dodged around corners twice to avoid Sigurd on his way to and from the collection of the Hydromel, and then when he'd arrived on the receiving platform it had been just in time to see the elevator dropping away. He'd followed it down by the stairs and catwalks, and stayed in the shadows as he tried to get some idea of how the Terminus was being run. His observations led him to the unattended equipment store, and there he'd been able to a.s.semble for himself a disguise that would allow him to move around unchallenged.

The Garm was starting to move towards them.

'You'd better make this fast,' Nyssa said.

But it wasn't going to be easy. The manacle had been closed by some kind of sprung clip. It would take a lot more strength to open it than Olvir could muster.

'Don't worry,' he rea.s.sured her, 'I'll stop him.' He took a couple of steps back, reaching under his Vanir cloak as he went. He brought out his burner and levelled it at the Garm. He set it for low heat and high energy, the brick-wall effect that came out in a single concentrated zap.

It might have been a paper cup full of water. The Garm didn't even slow down. Olvir switched to a concentrated burn humane impulses were all very well, but the situation was getting away from him and tried again.

Nothing. He had to end the burn abruptly because the Garm was too close to Nyssa and she was at risk.

The thing must have had skin like a rock. It reached out and sprang the manacle in a single easy gesture, and then swept Nyssa off the ground before she could even react.

He was carrying her away, into the Terminus.

There was nothing that Olvir could do about it.

'I'll think of something else,' he called after her.

At least, he would try.

'Nothing,' Turlough said as he threw the last of the switches. With a few inconsequential exceptions, none of them had any effect. They could lower the control room lights or boost the air-conditioning, but they could neither get out of the ship nor let others in.

Tegan said, 'Everything's routed through the automatic pilot.'

'So we're stuck here until that box decides to let us out?'

'We don't have any choice.'

'I think we do,' Turlough said, and Tegan sensed that he was finally getting around to explain what had been bothering him for some time. 'I think there's a way we can get back to the TARDIS.'

'It would be more practical to find the Doctor.'

Turlough shook his head. 'Not at all. It would be more practical to recreate the door we came through.

Wait here.'

He walked out of the control room with an obvious sense of purpose. Confused, Tegan watched him go.

Whatever was going through his mind, he didn't seem ready to share it.

As soon as Turlough was certain that Tegan wasn't following, he took the communication cube from his pocket. He was fairly sure that he couldn't be overheard.

The Black Guardian came through immediately.

' You have not destroyed the Doctor You have not destroyed the Doctor,' the cube pulsed, the ferocity of its glow an accusation.

'I haven't found him yet.'