'You've been reading too many story books, Doc. We're going now. If you follow, Benny gets to play the Swiss cheese in the next Heletian production of The Mousetrap.

He reached into the shuttle and yanked out a large casket with the Lance of Aggedor strapped to its top.

'Centauri, stay here,' commanded the Doctor. 'Lord Savaar, Sskeet, please follow me.'

Together the three slowly followed Reece and Bernice into the darkness.

The light blinked out and the refinery was plunged into total darkness. For a moment nothing seemed to happen; the blackness of Megeshra's deepest cavern remained undisturbed. Then there was a noise - a high-pitched whine and the solid metal door to the refinery swung open.

Ten pairs of red eyes glared into the darkness, infra-red filters clearly showing every rock, every treacherous lump of roak to be avoided.

Like a well-oiled machine, ten pairs of feet moved together in unison. Ten right arms moved up to waist height, pointing forward, built-in sonic disrupters primed and ready.

One by one they trooped out of the dark refinery and into the equally shadowy cavern. Not every warrior was identical: Martians came in as many varied shapes and sizes as humans, but they moved as one, grim determination etched into their lips. The last one out broke formation, turning, and with a whine of his sonic gun reset the alarm system.

Anyone trying to break into the refinery would receive the same neural attack that Neal Corry had suffered a day earlier. But with no one inside to turn it off, the effect would probably be fatal.

Commander Ra.s.sbur moved forward, his nine warriors following in perfect unison. Ten brave soldiers marching into war.

Lying in the dust near where they pa.s.sed by was the Doctor's travelling chess set. The pieces had been moved into a perfect checkmate - the black king surrounded by a p.a.w.n, a white knight, a bishop and, of course, the white king.

Townsend was getting unusually anxious. Something was wrong - not just with the plan but the whole set-up. He was angry with himself, more than anything. He rarely if ever got perturbed about any job, yet something was nagging at him over this. Some feeling that he'd overlooked an important point, a relevant aspect of the plan that he couldn't quite bring into focus.

He looked over at the other three. Cooper was her usual calm self, a sneer on her lips, as if working for a living was a ch.o.r.e to be endured. By the exit to the long tunnel leading to the back of the mountain where their shuttle rested, was Lambert. He seemed insanely happy, fidgeting about, checking his two blasters for the umpteenth time and patting down his Kelvar-8 body suit.

Then there was Sadler. She was just sitting, staring at the vacuum case.

Her blaster lay discarded at her side.

'Hey, Sadler, get your a.r.s.e into gear. I don't want slackness today.' As he spoke he knew he'd sounded more aggressive than he'd intended. Even Cooper shot him a look of amused contempt.

Sadler lazily turned and looked at him and stared. In turn Townsend caught Lambert's eye - he knew her best and something was wrong. Sadler's eyes were totally dead, as if someone had switched off her brain.

Anxiously Lambert moved towards her, an arm outstretched.

Do not let them touch you. Something is wrong. I feel Him near. He will try and destroy me. We must not let Him find us Leave. Now! Sadler stood up, grabbing the case and hugging it to her chest. In a lazy but precise movement she scooped up her blaster and aimed it straight at Lambert.

He backed away, complete surprise written all over his face.

'Sadler?' said Townsend. 'Sadler, what the frag are you doing?'

The redhead ignored him, keeping her gun aimed squarely at Lambert's chest. He moved away from the exit and she started towards it, now covering all three of her comrades. Silently she started backwards down the tunnel and after a few seconds was swallowed up by the darkness.

Townsend released his breath. 'Phew. What was that all about?' Cooper just stared down the tunnel. 'Never liked her. Now she's taken away our deposit.'

Townsend turned to Lambert. 'Get after her. Talk some sense into her - we need the Diadem back here. Now.'

Lambert nodded dumbly and, confused, headed off after Sadler.

Cooper checked her blaster for the tenth time. 'Was that wise?'

'How d'you mean?'

'They're what pa.s.ses for a couple. He's hardly going to gun her down, is he?'

'No, but he's more likely to talk sense into her than you are. And I'm staying here to meet our man.'

'You mean you don't fancy Sadler blowing your head off.'

'There is that,' said Townsend, but all trace of humour had left his voice.

His premonition had come true. Everything was going wrong.

'Maybe,' suggested Cooper, 'just maybe we ought to go. Write this one off.'

'Maybe,' replied Townsend. 'But not quite yet.'

Lambert was totally lost. The tunnel was going down and that seemed right.

But every time he stopped to listen, he couldn't hear anything from up ahead. Sadler didn't have that much of a head start.

What was that? Footsteps? Laboured breathing? It certainly wasn't Sadler.

There was more than one. He dropped to the ground, and placed his palm down. The ground didn't allow really accurate vibrations to travel that way but experience told him there were more than half a dozen. Maybe eight or ten. And big - whatever they were.

Lambert silently leaped behind a crop of rocks, his instinctive survival expertise kicking into gear. Through a tiny crack he watched as ten Martians walked up the tunnel, along the route he'd just come. In a few moments, they'd certainly encounter Townsend and Cooper.

Should he warn them? Nah, Martian helmets were fitted with sophisticated receivers; the slightest warning and they'd cut him down as he spoke.

Besides, Townsend could look after himself. Sadler was far more important.

He waited two minutes to give the Martians time to be right out of audio range and then, as silently as possible, carried on.

After a few seconds he encountered a small cavern where his tunnel branched off. Left or right. He couldn't remember. Think - the shuttle was behind the mountain. It had to be to the left. As he approached the two entrances, he scanned the floor as best he could in the dark. Scuffle-marks, but Sadler's or the Martians'? No way of knowing. Breathing deeply, he set off down the left-hand tunnel.

After a few moments, he knew he was wrong. None of this looked familiar and while to the average eye all the Pel tunnels probably looked alike, Lambert was trained better. He had noted odd-shaped rocks, strange scratches and peculiar stalact.i.tes on the way up. None of those were here.

He turned to go back when a minute flash caught his eye. His blaster had reflected a tiny amount of light off something metallic.

He slowly crawled forward.

And went flat on his face.

Cursing, Lambert scrambled up. At his feet were the crushed remains of an archaic chess set.

Must have tripped over that, he decided. b.l.o.o.d.y stupid thing to do.

He'd dropped his blaster and it was too dark to find it. But that metal thing had been ahead. As his eyes grew accustomed to the dark, he realized it was a door, with a ma.s.sive window beside it. No lights were on but he tried to peer through.

Nothing. Just blackness.

He reached out for the door and gave it a slight push.

For a split second, Lambert's mind recognized a typical Federation neural alarm system. Another split second and his mind was shut down by the excessive force of the noise and lights. Falling against the door, the alarm continued. It was silent to anyone else but inside Lambert's head, it rang louder and shriller than anything else in the universe. After twenty seconds every neural pathway in Lambert's brain was scrambled irreparably.

Comatose, he slumped into the dust, the alarm shutting off. He was destined to lie there for the rest of his life, which would not be very long. As his body registered no signals or impulses from an already destroyed brain, it slowly cut off each of its functions. His lungs would soon stop drawing air, his liver and kidneys would stop producing enzymes and his heart would eventually give up pumping blood and oxygen around his body.

In twelve minutes, Lambert would be dead.

Blissfully unaware that her lover was dying, the autonomic Sadler was striding back to the shuttle.

As she walked out of the dark tunnel into the open air, her eyes made no adjustment to the light, instantly damaging her retinas. The wind and rain lashed down on her, but she gave no sign of noticing it.

The shuttle. Get me away from Him. Far away. Then we can begin again, where He cannot locate us.

Moments later, Sadler reached the shuttle entrance and commanded it to open. The wall melted away and then rea.s.sembled after she got in.

As she sat in the pilot's chair, Sadler's body gave a slight shudder.

Deep within her rapidly closing-down mind, the real Sadler was screaming and crying, trying to fight off the evil power that controlled her body. She was aware that she was losing. She felt the shudder: somewhere back inside Mount Megeshra, Andrew Lambert had breathed his final breath and was clinically dead. Sadler's own mind and personality finally gave way and allowed the evil to swamp her mind.

Siobhan Sadler was gone.

In the real world, the hands of Sadler tugged on the case's lid and with a hiss of air the top shot back. Sadler's hands reached down and grasped the Ancient Diadem of Pakhar, the jewels glowing in frantic patterns. The hands placed the circlet around her forehead.

As the ends touched Sadler's temples, the living evil that was the Diadem swarmed into her brain, finally eradicating any vestiges of Sadler that might have remained.

'A new body. At last.' The Ancient Diadem was free and mobile.

The galaxy, eventually the whole universe - perhaps even the fabric of time and s.p.a.ce - was once again open to total domination.

Bernice Summerfield had encountered a lot of dangerous, even potentially lethal situations since she'd teamed up with the Doctor. She guessed that she ought to be used to having madmen point blasters against her head while having a primed grenade in their pockets.

She wasn't.

'Look, what exactly are you going to achieve? I mean, they can cut you down pretty easily. In case you haven't noticed, Martians don't tire quite as easily as we do.'

Reece snarled back, 'They're b.l.o.o.d.y slow though. My a.s.sociates have a shuttle. We can be on it before they catch up.'

Actually,' corrected Bernice, t's a bit of a fallacy that Martians are slow.

When they need to be, they can be rather swift.'

Reece stopped. 'Townsend?'

Bernice was not unsurprised to hear a male voice call back. 'Here. Have you got the stuff?'

Of course,' was Reece's only response. He dragged Bernice a little further into the darkness and then she saw light. They entered a cavern with a sheer drop at the far side. She could just see the Citadel below. I just know he's going to put me near the edge, she thought. And I hate heights.

Reece pulled Bernice towards the ravine. 'Look. Down there.'

It's a long way down. Nice view though,' was all she could manage.

If the Doctor or Savaar come within thirty meters of us, you're going to get a better one.'

'G.o.d, you're predictable. What's the point? I thought I was a hostage.'

'I'm desperate. Maybe it's a bluff, maybe not. But it'll hold them back anyway.'

The other man, who Bernice guessed was Townsend, wandered over. By the opposite tunnel entrance, looking down it anxiously, was a woman with closely cropped brown hair. She turned round and spoke.

'No sign. Either she's shot him or they've both skipped: Reece relaxed his hold on Bernice enough that he could force her to sit on the floor, but still twisted her wrist and held his blaster at the top of her head. She didn't bother resisting.

'What's she talking about, Townsend?' 'Guess.'

Reece looked at Cooper and then Townsend. I don't believe it.'

Townsend sighed. Okay, I made a mistake.'

'You cretin, how could you? You people just cannot be trusted.' Reece slid the casket off his back on to the floor. He pointed at Cooper. 'Coop. You carry this.'

Cooper looked at Townsend for confirmation - she didn't exactly hold him in high regard but nevertheless he was the leader, not the newcomer.

Townsend nodded and Cooper hitched the casket on to her back.

'Reece!' Bernice turned at the Doctor's voice. He stood, unarmed, by the entrance to the cavern. Savaar and Skeet were faintly visible behind him.

'Reece, let the professor go.'

'Why should I, Doctor?'

'Because she's useless to you now.'

Oh. Cheers, Doctor.' Bernice tried to get up but Reece twisted her wrist harder. Ow! That ruddy well hurt.'

I mean it, Reece. Let my friend go or the Martians will destroy you.'

Townsend brought his blaster up to cover the Doctor and Cooper did the same.

'Three against two, Doctor. Good odds, I think you'll agree,' laughed Reece. 'Now back off.'

The Doctor took a few steps back. 'Bernice, I'm sorry. But Reece has to be stopped.'

'Hey, I'm not wild about it either. But okay.'

The Doctor tried one last time. 'Reece, the Diadem possesses more power than you can imagine. It's not just an object, or a focusing device for mental powers as the legends claim. I've seen it used. It's a living being, a being of pure evil. It feeds off negative thoughts and emotions, slowly encroaching upon the mind. It absorbs you totally.'

Bernice saw a look pa.s.s between Cooper and Townsend. Of course! That's what they meant about the others going missing.