The next room was larger and quite obviously a lab of some sort; there were humming computer banks and monitor screens ranged along the walls and a number of workbenches full of scientific apparatus. The Doctor immediately began to inspect the equipment.

'But what is this place?' wondered Tegan. 'Some kind of secret base?'

'More likely some sort of scientific research establishment,' the Doctor said. 'Entirely self-contained, but very probably secret, judging by its location.'

'Research into what?' asked Stoker.

'Well, there's a lot of calibration equipment for stasis field generators and such like here. I'd say that they were researching suspended animation techniques.'

'"They"?' queried Bunny.

'Whoever worked here'

'And where are they now?'

'Good question.'

'Maybe they finished up and left,' suggested Stoker hopefully. 'The place looks abandoned.'

'You're forgetting two very important things,' the Doctor pointed out. 'Firstly, the power had been left on. Somewhere there's a generator still running. Not usually the action of someone abandoning a place for good, unless they had to leave in a terrible hurry.'

'And secondly?'

'The most interesting thing.' the outer door was locked from the inside, remember.' inside, remember.'

'You mean, whoever lived or worked here... should still be be here?' here?'

Tegan hugged herself as she looked around the empty room. 'That feels kind of weird, Doctor.'

'Hmm,' the Doctor seemed suddenly distracted, squatting down again to pick up a fallen beaker. He examined it closely for a moment, then looked across the lab to where a plastic tray lay propped up against the wall.

'You're about to add a third "interesting thing" to the list of things we've overlooked, aren't you?' Stoker realised.

The Doctor nodded thoughtfully. 'The items on the floor in here, and the overturned chair in the first room. Signs of a struggle of some sort, would you say?'

Bunny Cheung said, 'I really don't like the sound of this.'

'I'd like to ask Vega Jaal to come down here,' the Doctor said as he stood up.

Stoker looked puzzled. 'Jaal? Why?'

'I think he might be able to help. We're underground, in his element'

Stoker considered the request for a second and then sent Bunny to fetch the Vegan. Then she took out a cigar from her jacket pocket and lit it. 'Y'know, I really don't like the idea that someone has been here before before me.' me.'

'You're just worried about losing your precious lexium,'

said Tegan.

Stoker blew a perfect smoke ring. 'I'm not allowed to stake a claim on consecrated ground or anywhere with specific religious significance. I haven't seen evidence of either yet.'

The Doctor looked at her curiously. 'Loopholes, Ms Stoker?'

'You bet. Quite apart from my own personal ambitions, Doctor, I have my men to think about. They rely on me for a living. If there's any way I can complete my claim for mining rights to this moon, I will.'

'That sounds very mercenary,' said Tegan.

'We all have to make a living. And I owe it to my team to see them right. I'm not giving up this moon without a fight?'

Nyssa sat quietly with Vega Jaal. She had found him to be intelligent and considerate, but he was rather gloomy company. She felt unaccountably relieved when Bunny Cheung arrived and said, 'Stoker wants you, Jaal.'

'You mean the Doctor wants me.' Vega Jaal gave Nyssa a sad smile and got up to leave.

'I'll come with you,' Nyssa said, standing up. She already felt a little guilty.

'You are not well enough,' Jaal said.

'No, I insist. I feel a lot better thanks to you.'

'I'm sure I've done nothing'

Nyssa smiled. 'On the contrary, you have made me realise that my feelings, my instincts, are every bit as valuable as my intelligence. It is only a question of interpretation.'

'We'd better go,' said Bunny Cheung. 'Wouldn't do to keep Stoker waiting.'

Nyssa was surprised and heartened by the sight of a well-lit, functional laboratory complex. Its mundane appearance lent her strength.

'Hi there,' said Tegan. 'Feeling better?'

Nyssa said, 'You've been busy.'

'Not really. The Doctor found the light switch, that's all.'

Ah, Vega Jaal,' said the Doctor. 'Good of you to come.'

The Vegan nodded formally and then c.o.c.ked his head slightly, as if listening for something. 'Can you hear it?' he asked.

'Hear what?'

'The cry of a dying planet: born on the wind of time and trapped in the rock that surrounds us; the eternal scream of a world desecrated and turned into evil.'

A stunned silence was met with Stoker's slow hand-clap.

'Oh, bravo.'

Even the Doctor looked a little fl.u.s.tered. 'Well, er, Vega Jaal... now we know what you can, er, hear. Could you please tell us what you feel feel down here? I was hoping to make use of your natural geological senses.' down here? I was hoping to make use of your natural geological senses.'

'I feel death,' said Jaal simply. 'All around us, and near every one of us.'

'Oh, for pity's sake!' exploded Stoker as as her patience finally wore through. 'I don't employ you to frighten everyone with this pseudomystical claptrap, Jaal!' her patience finally wore through. 'I don't employ you to frighten everyone with this pseudomystical claptrap, Jaal!'

'No, wait, please,' the Doctor urged.

Vega Jaal raised a hand to cover his eyes, clearly distressed. He said, 'It is very bright in here. But death is waiting in the darkness. It watches us from the shadows.

Tegan said, 'I'm sorry Doctor, but this is giving me the creeps.'

'See?' Stoker demanded.

The Doctor ignored them both, stepping closer to Jaal and saying, 'There's more, isn't there? Something you're not telling us.'

Jaal shuddered. 'Death is coming for all of us. Me.

Stoker. Bunny. Your friends. Even you, Doctor.'

'n.o.body lives forever,' said the Doctor.

Jaal's eyes burned. 'But you will die many times over, Doctor.'

'I already have.'

'Not like this!' Jaal's voice was a rasping whisper now.

'Death after death...!' after death...!' For a long moment he and the Doctor stared at each other, and then the Vegan abruptly collapsed. For a long moment he and the Doctor stared at each other, and then the Vegan abruptly collapsed.

The Doctor only just managed to catch him as he fell. Stoker helped him to lower Jaal into a chair.

'Get some water, quick,' Stoker ordered, and Tegan left immediately.

Satisfied that Vega Jaal had only fainted, the Doctor turned to Nyssa. 'How are you feeling, Nyssa?'

'Scared.'

'Jolly good! That's only natural. I'd have been more worried if you weren't.'

'Why did you make him do that?' Nyssa asked. Her anxiety was giving way to anger. Sometimes the Doctor's casual disregard for other people's fears irked her. She grasped Vega Jaal's hand and his large eyes flickered open.

'I apologise,' the Vegan murmured weakly.

'It's all right. The Doctor had no right to let you -'

'The Doctor had every right,' Jaal contradicted her firmly.

The Doctor said, 'Something is affecting us all: Vega Jaal is acutely sensitive to it, whatever it may be. At the moment, Jaal is out best chance of determining what it is, or where exactly it might be'

'You're using him,' stated Nyssa.

'I know.'

'Let's not argue the rights and wrongs of it,' said Bunny Cheung. 'Let's just get it over with. Jaal, have you any idea what's going on?'

The Vegan shook his head sadly. 'No. I still sense only death, and total, irredeemable darkness.'

'Well that's just great,' said Stoker.

'It could be anything from an ultra-dense psionic field to a particularly high level of positive ions in the atmosphere,' said the Doctor.

Nyssa felt on more familiar ground now. 'Which do you think it is?'

'Neither, to be perfectly honest. But something is manipulating our perceptions down here, both ordinary and extra-sensory. But it's very subtle. I want Vega Jaal to tell us if he can detect any kind of focus'

'Through there,' said Jaal, pointing.

They all looked at the wall, where the Vegan had indicated.

Stoker sighed. 'It's just a blank wall, for goodness' sake.'

'But what's on the other side of it, I wonder?'

'A load of rock,' Bunny said.

'No, I don't think so,' the Doctor said. 'Remember, Vega Jaal can sense cavities and voids through solid rock.' He moved to the wall and examined it, tracing the edges of the metal panelling with his fingers. 'I think this is another doorway. A secret door.'

'You're right,' Nyssa agreed. 'That is the only area of the wall clear of obstruction.'

Bunny joined the Doctor. 'There must be a way of opening it'

'Do we really want to, though?' Stoker said. 'I mean, if what Jaal says is true, it might be better to leave it shut.'

But the Doctor had found the switch, and the wall panel slid up into the ceiling with a buzz. A cold draft flicked at his hair. 'Too late,' said Vega Jaal.

'Dark again,' noted Bunny, peering into the black hole.

'Give me a torch, someone.'