The doors were open. Olvir looked at her for guidance, and she signalled him in. They came through together, crouching low to reduce the target, and turned their weapons onto an empty room.

Kari straightened slowly. She no longer believed that they might be facing some kind of odd defensive strategy. What she sensed instead was a serious miscalculation. It was basically a standard control room, with tiers of crew positions facing a deep-set panoramic window that probably showed a simulation rather than a direct view of the distant stars. What made it unusual was the ugly piece of equipment under the window, obviously not a part of the original specification but grafted on. Lines and cables appeared to link this to the various crew controls, and other cables ran out to disappear under the floor grating.

Kari lowered her guard, and then, after only a moment's hesitation, she removed her pressure helmet. Following her lead, Olvir did the same.

'I don't get it,' she said.

Olvir looked around. It was his first mission as a member of an advance party, and everything was equally new to him. 'What's wrong?' he said, and as he turned towards her he made his first real mistake by bringing her into the firing area of his burner.

Kari guided the muzzle away firmly. 'The whole ship's rigged to run on automatics,' she said. 'It doesn't fit the briefing.'

'Can't we open the airlocks ourselves?'

'That's not the point.' Kari walked around the forward control desk for a closer look at the odd unit, leaving Olvir to stand alone. He looked at the nearest crew positon. The read-out screen and the picture symbols on the input keys seemed to indicate a navigation console. He reached out to press the nearest of the keys, wondering what might happen.

'Don't touch anything,' Kari said sharply. She didn't even seem to be looking his way. Olvir withdrew his hand as if it had been slapped.

Kari was still looking at what was probably the automated command centre that was guiding and operating the liner. Olvir waited out the silence for a while, and finally said, 'So... what next?'

'There's atmosphere, but no crew,' Kari said, thinking aloud. 'Doors that won't open. No cargo s.p.a.ce.' She turned unexpectedly, and fixed Olvir with a piercing stare. 'What does that mean to you?'

'No cargo?' Olvir hazarded.

Kari unclipped the radio from her belt. 'And it's supposed to be a merchant ship,' she said. 'I'm going to call the Chief.'

She opened the frequency and gave the call sign, and for a while they waited. There was no reason for the Chief not to respond. It was a part of the plan to establish contact when the bridge had been taken, but the radio stayed silent. Kari tried again.

'Bad signal?' Olvir suggested when there was still no reply, but Kari shook her head.

'It would register. Maybe it's the handset. You try.'

Olvir unclipped his own handset and gave the call sign, not really expecting to get any different result from Kari. He didn't.

'The gear's usually reliable,' Kari said, but the thought that followed it remained unspoken: I wish I I wish I could say the same about the Chief... could say the same about the Chief...

'Chief,' she said suddenly, 'I know you're listening.

It's not working out. We're coming back.'

'We can't,' Olvir pointed out, 'if he doesn't link with the airlock.' Kari looked at him then, and he saw the apprehension in her eyes. If something scared Kari, anybody else around who wasn't worried was probably seriously out of touch with the situation.

'He'd better,' she started to say, 'or...' She stopped abruptly. Voices! And coming their way!

For this, there was a procedure. Fear could wait, pushed out of the way by training and routine. Quickly she gave Olvir his orders.

No one knew more than the Doctor that they were in a difficult situation uninvited guests in an unknown environment but he was beginning to think that, with speed of action and a fast withdrawal, they'd be able to carry it off without too much danger. There was n.o.body around, they hadn't been challenged, and he was confident that he could remember the way back to the TARDIS where Tegan and Turlough would be waiting, as ordered. Considering the way events could have gone, they'd turned out well.

At least, that's what he'd thought until they came upon the plugged hole in the liner's outer skin.

Suddenly he was no longer so confident. 'This is new,'

he said, crossing the corridor for a closer look.

Nyssa didn't understand. 'New?'

The Doctor placed his hand on the surface of the hardened foam, carefully at first and then with increased pressure. Solid as rock. It didn't seem likely that it could have formed in the short time since he'd first pa.s.sed this way. The only other explanation was that he'd taken a wrong turn somewhere, and that they were in a new and unfamiliar part of the ship. He said to Nyssa, 'Do you remember anything at all about the way you came?'

But Nyssa shook her head. 'Nothing. I didn't know where I was going, or what I was doing. I just ran as you told me to.'

He touched the foam again. It wasn't even warm.

Well, he told himself, when you're offered a choice of explanations you have to pick the simplest, unless there's some good reason not to. And right now, there's no good reason to suppose we're anything other than... well, not lost, just a little way off the beam.

'We're on the right level, anyway,' he said, doing his best not to communicate any more anxiety to Nyssa.

She'd already been through enough. He pointed back down the corridor and said, 'It'll be this way.'

They started to move back. They were on the right level and in the main corridor, so it was really only a matter of time before they came across the TARDIS.

The slight curve of the pa.s.sageway suggested that, if they were to go on for long enough, they might eventually return to their starting-point in which case they had nothing to worry about. All they had to do was to keep going, and they'd cover the entire ship.

But the corridor didn't make a circuit. After a few minutes of walking and not finding the TARDIS, they came to the corridor's end and an open door. They hesitated long enough to make sure that the area ahead wasn't holding any nasty surprises for them, and then they went through.

'This has got to be the control room,' the Doctor explained, looking around. 'With any luck, we can find out where we are from here.'

The Doctor was no stranger to other people's s.p.a.cecraft, and he already had a reasonable idea of what to expect. Societies with limited experience and expertise in s.p.a.ce travel tend to produce short-hop craft of restricted capability and with control systems that look as if they would take a lifetime of study to master. More developed cultures tend towards a high level of automation, with simplified controls and, as often as not, some indication of their use that isn't tied to a single language or set of languages. The long-haul liner obviously fell into the second category.

Attempting to get some sense out of the inboard computers would be feasible, even if it was time wasting and tedious, but what the Doctor had in mind was something simpler. He wanted to check around the walls for a floor plan of the liner.

He didn't get the chance. As he and Nyssa approached the control desk, someone rose up from behind it and levelled a weapon at them. He was youngish, hardly more than a boy.

The Doctor quickly steered Nyssa around, saying, 'Sorry, didn't know it was private.' But their exit was already blocked. The rifle-like burner in the girl's hand came down to cover them, and she looked fully capable of using it.

'That's all right,' she said. 'We're in a mood for company.'

But somehow, the Doctor didn't feel that he could believe her.

'This makes twice in one day,' Turlough said as they hesitated at yet another junction of corridors. Every direction seemed the same. They hadn't even managed to find their way back to the main thoroughfare, and now they were having to move slowly because of the need to check for any robot drones that might be heading their way.

Tegan didn't understand. 'What do you mean?'

'You lost your way in the TARDIS, as well.'

'If it wasn't for your bright idea with the beads, we'd never have come this far.'

'Arguing won't get us out of here.'

'Maybe,' Tegan said, 'but it helps my temper.' The annoying part about it was that he was right.

There were no more drones, so they took a guess and moved on. They'd seen one more of the robots, with a different coloured bodysh.e.l.l and a different set of tools. It had crossed their path some way ahead and had paid them no attention. This wasn't really enough to make them feel safe it only meant that, at the time, whatever they'd been doing hadn't raised any objection from its programming. Let them wander into some unmarked but proscribed area, and the reaction might be different.

The plaintive calling that had lured them down had stopped shortly after they'd tried to turn back. Tegan was doing her best not to think about it. But she could hardly put it from her mind when it started again not when it was coming from the other side of a door that was only a few metres behind them.

It came through as a distinct Help me Help me. Tegan was transformed; she rushed to the door and pressed her head against it to listen. 'That's her,' she said, 'that's Nyssa!'

Turlough wasn't so sure. Even though they hadn't known where they were heading, they'd come a long way from their turn-around point, a place where they'd supposedly been getting near to the source.

'That could have been anybody,' he said, but Tegan was already convinced.

'Nyssa?' she said loudly, doing her best to make herself heard through the thickness of the door.

'Nyssa, are you there?'

A faint but unmistakable response came through.

Tegan looked around at Turlough in triumph, as if she'd had absolute confirmation.

'It's the Doctor we have to find,' he was starting to say, but Tegan wasn't even listening.

'See?' she said. 'We've got to get the door open!'

Whilst Tegan was trying to find a way to open a sliding door that has no handle and no visible controls on the outside, the Doctor and Nyssa were sitting in two of the crew chairs in the control room of the liner.

Weapons covered them from both sides, and the raiders with the weapons obviously knew how to use them.

It hadn't taken long for the Doctor to add an empty liner to a foam-plugged hole and work out how the newcomers came to be here. What he couldn't answer quite so easily was the question why why? In the meantime, he could see no advantage either in lying or in concealing his own motives for being on the liner.

'You've got a ship?' Kari said at the first mention of the TARDIS. 'Where is it?'

'That's the problem,' the Doctor said. 'We can't find it.' 'Is it armed?'

The Doctor and Nyssa both spoke together. 'No,'

they said, and then exchanged a glance. They wanted to present themselves neither as potential enemies nor as allies to be pressed into service. The Doctor added, 'We're not looking for trouble, we're just pa.s.sing through.'

Kari turned her weapon slightly and flicked a switch on its side. The movement seemed to be as much for their benefit as for any practical purpose. The burner emitted a high-pitched whine, and a red indicator light blinked alongside the switch. She flicked it off, and the whine stopped.

'I'm not convinced,' she said.

'This is all very one-sided,' the Doctor objected.

'I know.'

Olvir's attention, meanwhile, had drifted from them and was now directed more towards the panoramic window at the forward end of the bridge. 'Kari,' he said, and the undertone of warning caused her to glance his way. It was then that she saw the moving shadows around one of the ports, the first indication of an approaching light-source somewhere outside.

'Watch them,' she said to Olvir, and she crossed over to the window to take a look.

The Doctor had already weighed the possibility of making a run for it, and dismissed the idea. Olvir might be number two in the raider hierarchy, but he still knew what he was doing. Even if they made it out into the corridor, they'd be perfect targets. From his seat by what was probably the liner's manual helm, the Doctor watched as Kari stared out at something they couldn't see. She seemed to be getting paler and paler, all of her colour bleaching away until she had to turn aside from the brightness or be blinded. The windowgla.s.s reacted a moment later, darkening in response to the photon overload as a deep rumble made itself felt all the way through the control room.

Olvir couldn't help it. He had to see. He continued to keep the Doctor and Nyssa within his firing arc as he backed over to the window but he switched his attention away from them for a moment. Nyssa looked at the Doctor, but the Doctor shook his head.

'That's our ship!' Olvir said in disbelief.

Kari had unclipped her radio from her belt and was making a hasty attempt to communicate. 'Chief,' she said, 'this is the advance party. What's happening?'

But Olvir had already guessed. It was the obvious sequel to the lack of follow-up and the long radio silence a silence which even now wasn't to be broken.

'He's running out on us!' he said.

'He can't!' Kari tried again, but her only reply was a deafening wash of static as the raid ship's engines burned their way past. She switched off. The quiet of deep s.p.a.ce was abruptly back with them, the only background sounds those of the liner's engines running themselves up in preparation for some automated manoeuvre.

The Doctor leaned fractionally towards Nyssa. She looked at him, eager to hear the plan of action that would get them out of this mess.

'Any ideas?' he said.

'It's the motors,' Turlough said as he stepped back from the door, and he listened for a moment to be certain. 'Something's happening.'

Tegan didn't even seem to hear. They'd found that, by pressing hard and putting all of their strength into it, they could make the door give just a little. It wasn't enough to be of any real use, but it looked like progress. She said, 'Hold on, Nyssa, we're getting you out.'

Turlough had his own reasons for being helpful. His sights were set, not on Nyssa, but on the Doctor.

Helping Tegan was only a way of keeping his cover intact whilst he waited for the opportunity that the Black Guardian had a.s.sured him would come. He said, 'We need a crowbar. Something to lever the door open.'

'Well, find one!'