86.'If they're intercepting us,' said Zatopek, 'why are they slowing down?'

's.p.a.ce combat isn't like dogfighting a flitter,' said the Doctor.

'There's no point arriving at your target and then zipping past it.

You've got to be slow enough, relative to your target, for your weapons to hit it.'

It was more complicated than that, Chris knew. The high-V weapons like the ASDACs traded off warhead for engine size. If you launched while on an intercept vector they could rip apart a ship just with the kinetic energy of their impact, much less effective at low or negative closure.

The low-V missiles like the Roscoes traded the other way: big warhead for a proximity hit, but the engine was smaller. Each weapon had its own effective envelope based on the absolute distance from launch to target and the relative velocity. The fighters were on a relatively simple intercept from behind and above, simple enough for even the Hopper's navigation computer to make the necessary calculations.

The fighters were closing at less than seventy kilometres per second. Too late, Chris reckoned, for them to bother with their ASDACs. Once they were below twenty kilometres per second they would be at minimum effective V for the Roscoes. Which would mean that they were going for a visual inspection and a little bit of cursory intimidation.

Unless they used their proton cannons. In which case the Hopper didn't stand a chance.

'Chris,' said the Doctor, 'I think you should stop broadcasting Jimmy Somerville now we don't want to get them annoyed.'

Chris winced and unplugged the Walkman from the navigation console, which immediately began to bleep at him. He'd forgotten all about it.

Iaomnet turned to the Doctor. 'If this is just an inspection, why haven't they hailed us?'

'They probably wondered who was strangling the cat,' said the Doctor.

Chris flipped a switch and the bleeping stopped. 'h.e.l.lo, unidentified Hopper,' said a speaker. 'Do please reply. We're becoming a little anxious.'

87.Chris tapped a control. 'h.e.l.lo there,' he said. 'Sorry to keep you waiting, we had a minor communications glitch.'

'Not a problem, unidentified Hopper, we were enjoying the music. This is the interceptor Albert Edward Albert Edward, out of the ISN Victoria. Could we please have your ident code?'

'Yes, ma'am. We're an intersystem Hopper out of Earth, bound for Iphigenia, Ident X181/481.'

'And so you are. Many thanks for your a.s.sistance, and a safe journey.'

'And you. Thanks.' Chris closed the link.

Everyone in the c.o.c.kpit let out the breath they'd been holding.

The Hopper slid into orbit around Iphigenia at 07.00 hours, ship's time, a tiny dot swinging around Clytemnestra's innermost moon. The gas giant was a ma.s.sive, faintly glowing ball, cutting off the sunlight, filling the bridge with soft reddish shadows.

Chris and Iaomnet were sitting side by side. She was keeping an eye on navigation while he watched the sensor array. Zatopek had given him a series of diagnostics to run, comparing the close-range data with the long-range scans they'd done en route. Two days' worth of recordings, all of the wrong side of the planetoid, Aulis Crater tantalizingly hidden on the other side.

It was all checking out perfectly, a detailed map of the surface slowly unscrolling in the computer's memory. 'Ten minutes to Aulis Crater,' said Iaomnet.

'So,' said Chris, 'what do you reckon we're going to find down there?'

'I don't know,' she said. 'I thought I was just here to make sure the academics didn't fall out of an airlock or something. But an ancient, alien construct... There might be a whole city under there.'

Chris ran his eyes over the controls. Something was trying to get his attention. Had he missed a telltale? 'Hidden under the mountain all this time,' he said. 'For millions of years, maybe.

And we'll be the first people to visit it.'

'Great,' said Iaomnet. 'I hate places with too many tourists. I just hope n.o.body's home.'

'Do you travel a lot?'

88.'Not much, no,' she said. 'The truth is, I ' From somewhere aft there came shouts, followed by an appalling, high-pitched scream. 's.h.i.t!'

'Stay here,' said Chris, jumping up. He almost collided with the Doctor, who dashed in through the doorway.

'It's Zatopek,' said the Time Lord. 'Give me your personal stereo.'

'What?' said Iaomnet, unable to take her eyes off the controls.

Chris didn't hesitate, s.n.a.t.c.hing the Walkman out of its socket in the console. Kim Wilde vanished in a puff of silence. The Doctor took the Walkman and grabbed Chris's bag of tapes and bolted.

Chris followed him. In the galley, Zatopek was in convulsions, lying on the table and screaming in Czech. Martinique was trying to hold him down, grabbing at his head as it smacked against the plastic.

'I'm burning!' Zatopek shrieked. His dark hair was in disarray, like a black halo. 'Sailing in the lake of fire!'

The Doctor was frantically fiddling with the Walkman. 'What's wrong with him?' said Chris.

'Get us out of this...o...b..t,' said the Doctor.

'Planets emerging born out of the red sear in the lake, crawling above!' yelled Zatopek.

'Higher up?' asked Chris.

'No. Just get us into an orbit which doesn't cross the crater.'

The Doctor shrugged as though something was irritating him, and a tiny drop of blood ran out of his nose. ' Now Now, Chris.'

'Right away.' Chris turned and ran back to the bridge. Iaomnet was waiting. 'What's up?'

Chris flung himself into the seat next to her. 'We've got to change orbit,' he said. The acceleration plucked at them as they turned. 'What's the problem, Chris? Who screamed?'

'Zatopek,' said Chris. 'I think it's some kind of psychic attack.

Have you ever seen anything like that?'

'No, this is my first ' said Iaomnet. 'No, I haven't. Emil didn't tell me he was Gifted.'

Another yell came from aft. 'Merry Christmas, Emil,' said Chris.

89.

Half an hour later, the crew were gathered around the stricken psi. Zatopek was lying on the kitchen table, half covered by a first-aid blanket. He was murmuring about tacking across the wave of oblivion, hot chaos licking at the hull of his boat, and yelling at his neighbour to turn the noise down.

'This is terrible,' said Martinique. 'This is terrifying.' He looked at the device attached to his a.s.sistant's head. 'What is this, exactly?'

'I've used one of Chris's tapes to create a loop that will create interference in his neural pathways and reduce the intensity of the signal he's receiving,' said the Doctor.

'He doesn't look very happy,' said Iaomnet.

'For this to work, the noise has to be fairly radical.'

Chris picked up the remains of his ca.s.sette. 'Not "Don't Leave Me This Way"?'

The Doctor shook his head. 'It's a powerful source and we're still very close. I'm afraid I had to take drastic measures: Frankie Goes To Hollywood.'

'"Relax" or "Two Tribes"?'

'"Relax",' said the Doctor. 'The psycho buffer remix.'

'Ship's engineer, huh?' said Iaomnet.

'Could you take him to his quarters?' the Doctor asked her and Martinique. 'I think it's safe to move him now, and he needs a serious lie down.'

Chris watched as their pa.s.sengers scooped up the muttering Zatopek and carted him out. 'What about you?' he asked, when they were gone.

The Doctor blew his nose. 'I'm fine. There's a powerful psychic signal emanating from Iphigenia presumably from whatever's under Aulis Crater. The signal is much weaker here.

I'm able to filter out the random interference to a considerable extent.'

'What is the signal?' asked Chris. 'A message? Some kind of defence mechanism like a telepaths keep out telepaths keep out sign?' sign?'

'I think it's more in the nature of a leak. What's down there is very, very old, possibly damaged or worn down... A tiny amount of its power must be escaping.'

'Psychic pollution. So now what?' said Chris.

90.'We go back,' said the Doctor. 'And we land.'

Iaomnet slid Zatopek's wallet out of his jacket pocket and flipped through it. Chris had the impression she'd done this before.

'Land? Down there?' said Martinique. He was sitting beside the bed, anxiously watching his a.s.sistant. The telepath was half asleep, eyelids flickering, lips moving. The four of them barely fitted into Zatopek's cabin.

'Surely that's far too dangerous,' Martinique insisted. 'I'm not even sure if we should stay in orbit.'

Chris said, 'But you've come all this way. Shouldn't you at least find out what's down there?'

'No registration,' said Iaomnet. 'Either he left his inst.i.tute ident at home, or he's a Wild Card.' She looked at Martinique. 'Did you know he was a psi?'

'Of course not,' said the grey-haired professor. 'I was as surprised as any of you by the... attack he experienced.'

Iaomnet tucked the wallet back in Zatopek's pocket. 'Well, there's something going on here which I don't like,' she said, 'and I don't think we should proceed until we get some clarification.'

'But we can't abandon the mission now.'

'I thought you said you didn't want to land.'

'I'm not sure,' said the professor, glancing at his a.s.sistant. 'I don't know. He might need proper medical attention.'

'Exactly. I say we go home.'

'Well,' said Martinique, 'you're not in command of this mission.'

'No,' said Iaomnet, 'but what's the point of getting ourselves killed? How am I going to write that dissertation if I get fried?'

'We land,' said Zatopek.

They all looked down at him. He reached up and pushed one of the headphones away from his ear, the music spilling out in a recurring tinny hiss. 'I will be able to create a barrier in my mind, with a little work,' he said hoa.r.s.ely. 'I was taken unawares. But once I am ready, we must return to the crater.'

91.Martinique looked down at the younger man. 'Are you sure about this?' he said. 'Whatever's down there '

'We land,' insisted Zatopek, his voice heavy with some emotion Chris couldn't identify. 'We must discover the source of the power. There will be nothing more important we could do in our entire lives, Henri.' He looked at Chris. 'How long before we can return?'

The Adjudicator said, 'How long before you're ready?'

Iaomnet picked out the landing site, a smooth rock shelf close to the summit of Artemis Mons. Mons. Much too smooth. As the Hopper softly lowered itself, Zatopek and the Doctor peered out of the c.o.c.kpit window. Gazing into the shadowy cleft in the mountainside where the meteorite had torn through Artemis, trying to see the skull beneath her skin. Much too smooth. As the Hopper softly lowered itself, Zatopek and the Doctor peered out of the c.o.c.kpit window. Gazing into the shadowy cleft in the mountainside where the meteorite had torn through Artemis, trying to see the skull beneath her skin.

Chris obligingly switched on one of the vehicle's floodlights.

The beam stabbed into the gash. After a moment, their eyes adjusted.

There was a gentle b.u.mp as the Hopper's landing feet pressed against rock. Iaomnet shut down the engines. There was a moment of ringing quiet, that constant background noise absent for the first time in days.

No one noticed. They were all staring at the doors inside the mountain, the structures and shapes exposed to s.p.a.ce when the rock had been torn away.

After a few minutes, Martinique said, 'All right.' His voice quivered. 'Emil, Iaomnet, would you please accompany me to the airlock, where we'll suit up for EVA.'

'I think I'd better come with you,' said the Doctor. 'After what happened earlier, you may need a doctor.'

'He has a point,' said Iaomnet. 'I'd feel a lot better if he came with us.'

'The more, the merrier,' said Martinique. Zatopek opened his mouth to protest, but the professor went on, 'And hopefully the safer. Are you qualified for an EVA, Doctor?'

The Doctor grinned. 'I'm qualified in everything except HTML markup and dentistry. Chris, what are our Ogron friends up to?'

92.'They're in their quarters, as always,' said Chris. 'Probably playing ludo.'

'All right. We'll be on the surface in fifteen minutes. Get ready to track us.'

'Right.' Chris turned back to the controls.

A few minutes later, he heard the Doctor say, 'Testing, testing.

Who can hear me?'

'I can,' said Martinique.