The red robes of the Brotherhood of Rexulon flowed above his Kuabris armour. Many knights stared at him uncomprehendingly, but said nothing. They would get their explanation soon enough.

He'd enjoyed killing Argaabil. He had felt a grim satisfaction as the sword penetrated skin, fat, and muscle in a single movement. For a moment the man appeared to hold his stomach together before collapsing on to the floor. All who cavort with science and superst.i.tion would die like this, as would all knights that had lost sight of the true way. The brotherhood was a corrective grouping, no more: a remnant of the Higher that was now poised to seize all power in its own right.

This acquired power would be but a brief candle. Then there would come the final phase of the Higher's retribution.

And that would be glorious to behold.

And Zaitabor knew that he could now rely on Araboam to perform his duties well. The young man's life was hanging by a thread over the ice-cold moving mountains of h.e.l.l. He would not wander from the truth again, Higher be praised.

One detail needed attending to before the final meeting of the brotherhood. Zaitabor strode into his private rooms, dismissing the adviser who was waiting there. Then he walked to the window. He pushed it open, gasping in the sharp white air of the early morning. From here, high in one of the Kuabris towers, Zaitabor could see the smoking remains of the Furnace. How satisfying - and unexpected to all but the Higher - it had been to see a man of legend destroy the work of the men of science.

Zaitabor's strong hands gripped the window frame as he breathed deeply, his eyes closed. Then he raised the gla.s.s window and leant out over the sill, peering down the tower.

Just below his room hung one of the moth-men, shivering at the prospect of dawn. Its bejewelled eyes stared up at him. Its mouth opened, mandibles and probes crossing and clutching to produce the sounds. 'All has happened as you said it should.'

'Good.'

'One food supply was rescued.'

'A shortish man with dark hair? That does not matter now. Your reward awaits.'

'But the light -'

'a.s.semble all your people. The brotherhood meets at dawn. The early morning light will not harm you.'

The creature said something in its own tongue, and then launched itself off the tower, its huge wings a blur. The dark figure receded from view in some lowlying cloud.

Zaitabor closed the window and smiled.

'Oh dear,' said the Doctor almost the moment they stepped into the underground power station. 'I think this could be a fusion reactor after all. It might be highly unstable by now. I know these things are built to last, but there's long-wearing and there's long-wearing. If hundreds or thousands of years have pa.s.sed then I dread to think what's gone wrong.'

'I have never been inside this building before,' said the Dugraq as they walked down a well carpeted corridor. 'I am afraid I have no information for you.'

'Don't worry,' said the Doctor. 'They're usually based around similar principles. We're looking for the control centre. Come on!' After their leisurely walk across the city the Doctor suddenly sprinted, the Dugraq puffing and panting as he tried to keep up.

'Why do you not use the lifts?' asked the creature as the Doctor thundered down another set of stairs.

'Don't trust them!' exclaimed the Doctor. 'We don't know who's pulling the pulley.'

The long metal corridor they were in was covered with symbols and warnings. At the end was a huge gla.s.s door. It opened easily. As before, whoever had got the station up and running again was more interested in ease of access than security.

'The control room,' said the Doctor grandly.

The area beyond was huge and white and seemed, like much of the building, to have been hermetically sealed.

Rows of screens had been activated, each showing fast-scrolling data and graphical representations of output and danger thresholds. A keyboard stood neatly before each monitor, precisely aligned as if a cleaner had just gone round and tidied the place up ready for the next day's work.

There was a large metal shutter towards the far end of the room, and a blank screen in one corner. In front of it was a small raised dais, topped by plastileather-bound chairs with built-in executive terminals. The pot plant had died, leaving an ornate bowl full of mouldy earth.

The Doctor sat at one of the consoles in the main part of the room, pushing a headphone to one side. He began tapping furiously at the keyboard, nodding and tutting as the system presented more and more information. It was clear even to the Dugraq that a number of the graphs were swinging over into the red.

'Right,' said the Doctor. 'We've got to execute a type two emergency close-down procedure. I'll need your help on another console and then perhaps we can -'

'Stop,' sighed a huge voice. The Doctor and the Dugraq scout turned as an enormous humanoid stepped into the room. The crudely formed creature was the colour of clay and soil. A pendant covered with esoteric symbols hung from its neck but seemed to merge into its oily skin. 'You must not tamper with the instruments.'

'Listen to me,' said the Doctor urgently. 'I need to talk to your master. We're all in danger.'

The creature stopped a few yards from the Doctor, inclining its head slightly.

'You must contact Defrabax,' continued the Doctor. 'Tell him that this whole power station is unstable. I realize you've only got this running at less than a tenth of its full potential but -'

'My instructions are now to bring the station fully on-line,' explained the figure. It walked to the closest console and began stabbing in authorization codes with its blunt fingers. 'Do not attempt to interfere. I have a.s.sessed that I am much stronger than both of you. If either or both of you attempt to stop me performing my duties I will have to restrain you. And your bones and organs are very weak.'

'Don't bring the station on-line!' exclaimed the Doctor.

'Why?' asked the creature, although its fingers still tapped at the keyboard.

'Because if you do, you'll cause this entire plant to explode. In an instant you'll not only destroy this city, but the new world built over it.'

Thirteen.

As the creature lunged, Zoe dived to the floor. Its arms swept over her, rough skin tearing into her back. She sprang to her feet and ran towards the open furnace door, still hoping desperately that her ideas about the animal might prove correct.

Zoe turned to face the creature, her bruised back to the furnace's licking flames. The beast swung its head in her direction, its body swaying from side to side, but it did not see her. It seemed to know that she should be there, but could see nothing but the great heat.

There was a shout and both Zoe and the creature turned their heads towards the source. The twins were frantically screaming and jumping up and down. The creature looked back in Zoe's direction for the last time, perhaps deciding that the heat it saw was not that of an animal, and then trotted towards Raitak and Reisaz. It had a new target in its sight.

The twins darted towards the protective metal wall around the central turbine and kicked open a small gate. The creature followed them through, into the narrow maintenance area that ran around the entirety of the enormous hissing, clanking machine. Cogs and dynamos hummed, safety valves let off steam, and in the centre a huge wheel turned.

The creature's pursuit of the twins was halted by a sudden stinging spray of hot water. Zoe noticed that as Reisaz and Raitak ran they released valves and emergency cutouts, causing jets of steam to fly over the body of their pursuer.

The creature showed little pain, and continued its relentless, teasing search, peering through the broiling haze.

The turbine pounded a metallic beat, oblivious to the figures that moved around it. The twins were about halfway around the machine now, but the creature was gaining ground all the time. It made a deep hissing noise and then leapt at them, a lithe grey figure made dim by the steam. An outstretched claw caught the twins' right leg, and they tumbled to the ground.

As Zoe instinctively moved forward to try to help them Diseaeda dropped down on to the back of the creature from his hiding place on the turbine housing. He'd removed a huge greasy chain from somewhere and, as he pulled one arm as tightly as he could around the creature's neck, with the other he lashed out at the creature's face and snout. His first strike was a good one. There was a sharp splitting sound and something dark and viscous began to seep from under the bony plate that covered whatever pa.s.sed for its eyes.

The twins scrambled to their feet and hobbled towards Zoe. She struggled to help them over the metal fence, grabbing a fistful of clothing in each hand and simply tugging until they were over. She glanced at Diseaeda and the creature, marvelling at the man's adrenaline-fuelled strength. He clung to the back of the bucking creature and lashed out with the chain, the monster's arms not having enough flexibility to reach behind it.

An overall-clad man, roused by the noise, came running from the far end of the chamber. He was shouting something and rubbing the sleep from his eyes. But there was no time to talk.

Zoe reached for a pile of thick metal rods stacked against one wall and gripped one in her hands. She didn't really know what to do with it, but she had to try something. She ran back to the writhing figures, hoping to use her forward momentum to spear the creature.

It side-stepped quickly, Zoe's hand jarring painfully as the metal impacted against the solid side of the machine. The twins were swinging a similar pole at the creature but it stayed resolutely out of reach.

Diseaeda couldn't hold on forever and a harsh twist from the beast sent him spinning off There was a dull thud as his shoulders. .h.i.t the metal wall, his head snapping backwards, and then he slumped to the ground.

Ignoring the motionless figure the creature leapt over the fence, flicking the twins' metal bar away, and then bowled into them with an animal l.u.s.t. A foot thudded into their stomach, pinning them to the floor, and it bent down to finish them with its jaws, its teeth grinding inches from their screaming faces.

A flaming blast enveloped the monster's head and it jerked backwards. The man in the overalls had found some sort of huge blow-torch and aimed it unswervingly at the creature as the twins rolled away once more. In moments the animal was a humanoid cloud of flame. Then it leapt through the air at the man, knocking the device to the floor.

There was no finesse this time, no delicious savouring of fear. A claw burst into the man's rib-cage.

Much of the creature's head and shoulders had been blackened by the attack but it turned gracefully to study Zoe and the twins, flexing its huge b.l.o.o.d.y claws delicately as if to prove that it was unharmed.

'What do we do now?' asked Reisaz, her face blistered by the heat and stained with sweat and soot. Raitak's eyes were half-closed and she was breathing heavily, a huge gash across her forehead.

Zoe shook her head and said nothing. They began to shuffle back across the expansive floor of the generating plant, staring always at the creature coming towards them.

As they waited for the final attacking leap Zoe wondered what it would feel like as the claws snapped over bone and muscle or as the staring face of death swept down on hers.

The ancient android's fingers hovered over the keypad, and then cancelled the entry process. It walked over to the Doctor. 'Show me the relevant data,' it said.

'Well, I can't, not as such,' bl.u.s.tered the Doctor. 'You see, the readings that would absolutely prove what I am saying can only be accessed from the reactor core test room.'

The android made as if to begin keying in the codes again.

'But,' said the Doctor, 'let's find out, shall we?'

Defrabax has not been able to access the test room,' stated the android. 'He lost the key.'

'How unfortunate,' said the Doctor. 'Show me where this room is.'

The motionless android weighed up the situation.

'Please hurry,' said the Doctor. 'You can't afford to take that risk. Not even a military android would wantonly destroy so much life, including its own.'

'Defrabax plans to bring peace and prosperity to the city,'

said the android blandly.

'Exactly,' said the Doctor. 'Defrabax will be very angry if he finds that you've brought the entire power station on-line without making all the relevant checks.'

The android walked towards the thick metal door at the far end of the room. The Dugraq trotted behind them, deep in thought.

'This is the test room door,' said the android. He pointed to the rectangular slot where the key was supposed to fit.

'Let's see what we can do with this lock,' said the Doctor.

He made the android stretch out its broad hands and emptied into them the contents of his many pockets. The Dugraq's whiskers bristled with inquisitive interest. 'What are these things?'

'Sweets,' said the Doctor. 'Some prize marbles - no, please don't ask for an explanation now, we haven't the time. Compa.s.s. Tea bag - Darjeeling, perhaps? Pencil.

Paper clip. Stray marble. Another pencil. Eight-track ca.s.sette - still looking for something to play it on.

Screwdriver. A shopping list - the handwriting looks like Robert Burns'. I wonder if he's still waiting for his freedom and whisky?'

'Hurry, Doctor,' said the Dugraq, interest giving way to impatience.

'Aha!' exclaimed the Doctor. He withdrew a small bulb-like device with a silver thread attached. 'Found this on the floor of the TARDIS some time ago. I don't think it's essential, but it should help me open this door.'

'I used the medical emergency override codes to open all the other doors,' explained the android. 'Without the key I have been unable to open this one.'

'No matter,' said the Doctor. He reached into the slot, prized off the cover plate and gently tugged out what looked like a coiled stretch of white human hair. Then with the little device he'd found in his pockets he touched a number of wires experimentally. Occasionally the bulb would light up and the Doctor would smile. After some minutes of this delicate work the Doctor began to mumble to himself darkly.

'Oh, I could stand here all day trying to do it this way,' he said eventually. 'Let's try brute force.' And with that he took a pencil from the android's palm and shoved it into the thin wires, touching as many as possible.

There was a loud flash and the Doctor was hurled across the room. The Dugraq ran to his side, and shook him by the shoulders.

After what seemed like an age the Doctor's eyes flicked open. 'Oh, good gracious me,' he said. 'That gave me quite a turn.'

There was a further loud bang from the lock and the door slowly elevated into the ceiling. Beyond was a small room dominated by a huge gla.s.s window looking down towards the reactor core.