'Bit of a geologist, are you?'

'We are all geologists on Vega, Doctor. It is one of the fundamental skills of my people. On my planet, the basics of geology are taught in the nursery.'

The Doctor smiled. 'Of course. Porizium's quite valuable, isn't it?'

'I believe so, if there is a rich enough seam'

The Doctor seemed to ponder this for a moment, before carelessly discarding the stone and dusting his hands. 'What ancient civilisation are you hoping to find the remains of here?'

'Ah.' Vega Jaal suddenly appeared troubled. 'You will have to ask Stoker about that...'

'Don't you know?' the Doctor asked, puzzled.

Bunny was grinning wolfishly. 'Jaal's under orders not to say anything about it, Doctor. He's obsessed with the ghosts and ghouls of Akoshemon, and it drives Stoker up the wall!'

'Really!' The Doctor sounded very interested. 'Ghosts and ghouls?'

Vega Jaal said, 'The planet Akoshemon is infamous in this sector of s.p.a.ce. Its name is synonymous with cruelty and death. It is said that its diabolical inhabitants will never rest in their graves until...'

'How come you two have got time to stand around chatting?' demanded Stoker, stepping abruptly between Bunny and Vega Jaal. She looked to be in a furious temper.

'We've got a deadline to meet, remember!'

'I've never seen an archaeological dig in a hurry before,'

commented the Doctor.

Stoker cast him a black look and rounded on her men.

'Bunny, I want that word - now. now. Jaal, stop telling your ghost stories and get cracking on the cave survey, double quick!' Jaal, stop telling your ghost stories and get cracking on the cave survey, double quick!'

'We may get the opportunity to talk again later, Doctor,'

said Jaal. 'I hope so!' said the Doctor. 'I always enjoy a good ghost story.'

Stoker glowered at them both, and Vega Jaal, after a slight bow to the Doctor, left to attend to his duties.

'I'm way behind schedule and my best survey equipment's on the blink,' grumbled Stoker. 'I don't need any more gloom and doom from him, him, thank you.' thank you.'

'Is there anything I can do to help?' asked the Doctor.

Stoker lit a cigar and blew out a stream of smoke. 'Nope.

Thanks for the offer, but my next job is kicking Bunny's hairy a.r.s.e until it glows, and frankly, you ain't got the footwear for it.'

The Doctor looked at his white sports shoes and then at Stoker's steel-capped boots. 'Er, quite.'

'Now, if you'll excuse me,' Stoker muttered, and, chomping down on the cigar, set off after Bunny Cheung.

The Doctor suddenly found himself alone.

Stoker hauled Bunny Cheung into her makeshift office, a small s.p.a.ce behind the communications bank where he had spoken to Rosie. She was straight to the point. 'Your mistake, Bunny, could have cost us more than just time, but time is a real issue for us here. You know we're working against the clock.' if we don't find what we've come here for within the next couple of hours, I can't guarantee we won't be rumbled.'

'I wasn't to know there was anyone up there,' replied Bunny. He was trying to stay calm and reasonable, but Stoker was clearly under mounting pressure.

'That's not the point, and you know it!'

'So what is the point, Jyl?'

'The point is, I trust you to get it right. Every time. You're supposed to be an explosives expert. Act like one.'

'That's not fair.'

Stoker cut him down. 'Fair isn't the issue here. I don't know what the Doctor and his girlfriends are doing here, but you could've had them killed. Have you thought of that?'

'Of course I have. But you said it yourself we're working against the clock. You want those rock samples tested like yesterday. Fine. I set the CG bombs as normal, and I checked everyone was clear. I didn't realise there would be other people snooping around. We're supposed to be on our own here, remember?'

'I am aware of that fact, yes!' There was a moment's angry pause. Then Stoker said, 'Sorry, Bunny, but I can't help thinking your mind's not on the job.'

'Meaning?'

'Rosie! What's this got to do with her?'

'Come on, Bunny. Everyone knows you didn't want to come on this trip. We all know you can't wait to get back home. Rosie's a great kid, Bunny, the best. I envy you her, I really do. And you're a good father.'

'But?'

Stoker took a deep breath. 'But you're spending too much time on the hypernet, and maybe not enough time on your job. Besides, it's way too risky: what if someone picked up the simcord transmission stream?'

'Jyl. If I wasn't stuck here on this lousy lump of c.r.a.p in the middle of nowhere, I'd walk out on you right now. now.

Perhaps Stoker hadn't antic.i.p.ated the full extent of Bunny's feelings, because she seemed to be lost for words.

The silence steamed between them.

'But as there is no way off this rock,' Bunny continued eventually, 'I'll stick with you and do my best. But nothing nothing is going to stop me speaking to my daughter. Nothing.' is going to stop me speaking to my daughter. Nothing.'

Stoker had to concede defeat. She slapped a hand against the man's arm. 'OK, maybe I'm just getting jumpy. It's this d.a.m.n moon. I hate to admit it but Vega Jaal's right, there's something strange here... I just don't know what, exactly.'

She was clearly concerned, and Bunny's att.i.tude softened accordingly. 'Do you think this Doctor is going to be a problem?'

'I don't know.' Stoker reached a conclusion. 'Maybe I'd better find out.'

Left to his own devices, the Doctor and been taking a look around. He had come across a stack of packing crates against one wall, and, as there was no one in the immediate vicinity, he decided to take a quick peek.

He'd seen this variety of crate before: ex-military issue.

Nothing untoward about that, of course. Cheap military surplus equipment was widely used all over the universe. But he did wonder what was inside them. The Doctor felt sure that he and his companions had been caught in some kind of controlled-gravity blast, but neither Stoker nor Bunny Cheung had reacted when he had specifically referred to high explosives earlier. And military-issue CG bombs were most definitely not your average high explosives.

Of course, the packing crates were all sealed. After only a moment's hesitation, and another quick check to make sure the coast was clear, the Doctor fished out a screwdriver from his coat pocket and began to prise open one of the crates.

'Looking for something?' Stoker asked from behind him.

The Doctor leapt away from the crates, scratching his head in an obvious attempt to distract her from what he had been doing. He dipped his other hand towards his coat pocket, missed it because of the flap, and was left with no choice but to slowly hold up the screwdriver for her to see.

'That's no use,' Stoker told him. 'Those crates have sonic locks.'

The Doctor glared ruefully at the screwdriver. 'Do they, indeed'

She took the tool off him. 'Bit antiquated, isn't it?'

'I generally find old-fashioned methods are the best.

She eyed him thoughtfully. 'I'll just bet you do.'

The Doctor thrust his hands into his trouser pockets. 'Tell me about Akoshemon.'

'Jaal spooked you already, has he?' Stoker signed.

'There's not all that much to tell, to be honest. It did have a pretty heavy reputation in these parts. A lot of bad stuff went on, war, famine, pestilence, that kind of thing. But it all happened a long time ago. It's completely lifeless now.' highly toxic atmosphere and a surface that's little more than an ocean of boiling mud and molten lava.'

'Sounds delightful,' said the Doctor.

'Jaal likes to tell his stories, though. You know the kind of thing.' evil spirits haunting a dead planet, ancient evil waiting for the chance to live again. Good campfire stuff, but I don't like him upsetting the others.'

'Is he that convincing?'

Stoker pulled a face. 'He has a way with him, you know?

He likes to do the mystic bit: like he has a sixth sense where he comes from.'

'Vegans are generally very attuned to the physical world around them,' the Doctor said. 'Some believe that connection exists on the spiritual level too.'

'Whatever,' said Stoker with a dismissive wave of her cigar. 'I just haven't got the time for it.'

Any further comment was interrupted by the arrival of one of Stoker's men. He looked fl.u.s.tered. 'Boss, there's some kind of fault on the a.n.a.lysers.'

Stoker looked heavenward. 'This is all I need. All right, Jim. I'm coming.' She turned to the Doctor. 'Sorry, duty calls.

I'll see you later.'

Tegan led Nyssa through one of the short tunnels that interconnected the caverns. Tegan was starting to get her bearings now, using bits of equipment or particular lamps as rudimentary landmarks.

When they found the Doctor, he was alone in a tunnel, staring thoughtfully at the rock wall. 'Fascinating geological structure, don't you think?' he asked as they approached.

'Doctor!' said Tegan. 'Nyssa's here.'

He whirled around with a delighted grin. 'Splendid! How are you feeling? Better? Good! Now, what do you think of this, hmm?' He turned back to inspect the rock. 'Not quite crystalline, is it?'

Reaching out to touch the surface of the wall, Nyssa said, 'It's like gla.s.s that cannot be seen through?

Tegan said, 'Or a whole pile of broken wine bottles jammed together.'

'It is opaque to your eyes, but translucent to mine,' said a Voice from behind them. They turned to see Vega Jaal standing in the tunnel, arms folded across his chest. His eyes glowed faintly in the semi-darkness.

'Allow me to introduce Vega Jaal,' said the Doctor. 'He enjoys a very good working relationship with every kind of rock. You could say it's in his nature'

'Not this rock, Doctor.' said Vega Jaal. 'This rock keeps a secret'

'Really! And what might that be?'

'I don't know. It's a secret'

The Doctor's face fell. Ask a silly question...'

'Have you tried to find out what it is?' asked Tegan.

Vega Jaal shook his head. 'Its secret is as as dark and impenetrable as the rock itself?' dark and impenetrable as the rock itself?'

The Doctor was clearly intrigued. 'You know more than you're letting on, Vega Jaal.'

'Stoker thinks I am a doomsayer,' replied the alien, 'but I simply speak my... mind.'

'I don't understand,' Nyssa said.

'I sense things.' hollows in the rock. Voids.'

Nyssa stiffened. 'Voids?'