What are you doing at this station, Lung? Get over to the coolant pumps and give me the pressure readi' The man leant in closer, his eyes peering in through the transparent eye-slit in the hood of Li's suit. 'You're not Lung! Who '

Li produced the Browning from the folds of his suit and shot the supervisor, who slid into the wall of the nearest turbine housing. The other technicians immediately threw themselves behind whatever piece of machinery they were closest to.

One brave soul, more foolhardy than the others, leapt up to try to wrestle the gun from him. The man was strong and Li's leg was weakening, but Li was trained for this sort of thing.

He was able to unbalance the man and shoot him. By this time, however, someone else had made it to the door, no doubt to call the guards outside.

Li turned at the sound of the door, ready to fire again, but he didn't have to. The unfortunate technician was already folding up as Sin marched into the room, making a beeline for the nearest technician. Li suddenly forgot about sabotaging the power supply; that dwarf had to be dealt with first.

A couple of technicians tried to pull Sin off their comrade, but this only made it easier for him to turn on them too. Blood squirted across the concrete floor as Li dashed past the struggling combatants and into the antechamber.

Not surprisingly, the guards outside were lying in sticky pools of clotting blood, but the weapons locker was untouched. Li pulled the key from the belt of one of the guards, ignoring the red slime that coated it, and unlocked the cupboard. Inside were not just pistols and Thompsons but also pistol grenade launchers German Kampfpistolen Kampfpistolen.

He looked back into the turbine chamber, horrified to see that Sin was now halfway through the chamber. Worse still, he had turned to look back up at Li. Sin had been grotesque enough to start with, but his face was now red and black with dried blood, like some tribal mask.

Two armed guards had escorted the Doctor and Romana from the control room, leading them down towards the grotto. This was where most of the cables had been, Romana remembered.

'Interesting,' the Doctor murmured. 'The whole mountain is filled with this stuff.'

'Yes, and as soon as that reactor comes on line, power will start resonating through the crystals in continuous feedback until it reaches the critical frequency, and then '

'Then zero-point energy. I don't think humans are ready for zero-point energy, do you?'

'Not yet, no.' They were dangerous enough, she thought, without being able to tap the potential energy of the universe itself. The term had been coined because it was energy that would still be present even in conditions of absolute zero; it hinged on the fact that the universe itself had a unique kinetic vibrational frequency.

'I don't think so either.' He nudged her and she wondered what he was up to now. She turned to deliver a put-down and saw him roll his eyes, as if pointing with them. She followed the look. A narrow sloping shaft opened up a few feet ahead.

Light from a tunnel in the lower level formed a spot on the ceiling of this one. Romana nodded, covering the movement with a cough for the benefit of the guards.

As they approached, the Doctor turned casually to the guards behind them. 'I hope you don't mind me asking, but where exactly are you taking ' He pointed behind them. 'Ye G.o.ds, man!' he bellowed. The guards didn't so much turn as jump round, at which point Romana and the Doctor leapt into the shaft. It was only about nine or ten feet deep and had a sandy floor, but Romana was jarred to the bone by the impact of landing.

Still, at least she wasn't stupid enough to twist her ankle, she thought proudly. The Doctor clutched her shoulder with an agonized expression. 'Romana, I think I've twisted my ankle.'

He sounded quite offended.

She gave it a quick once-over. 'Just a sprain.' He was such a baby, really. 'Never mind that now.' She dragged him into a pitch-black alcove and put a hand over his mouth to stifle his complaints. The guards jumped down into this new tunnel and looked around. If they checked the floor, they would find the footprints leading straight to their hiding-place, but she hoped the darkness would hide that.

The guards looked at each other. 'They have gone that way.

It leads away from the cells.'

His partner shook his head. 'Maybe that's what they want us to think. Besides, they don't know that. If we hurry we can still catch them...' Their voices faded as they wandered off down the tunnel. Romana and the Doctor stepped out of their hiding-place, looking up at the shaft. 'Well, we certainly can't climb back up,' Romana commented.

'No, but we might as well try to find a way out of here. I think it's very important that we be up there.' He limped along the corridor. 'This is totally unfair, you know.'

'Oh, stop whining. It's hardly a scratch.'

'Do you mind? I'm the one who's supposed to say that.'

'Say it then.'

The Doctor cleared his throat. 'Doctor, stop whining; it's hardly a scratch.' He paused. 'I don't believe me.'

Twenty-One.

i couldn't think of a rational and reasoned response to Sin.

Th L e brain's default settings ancient survival instincts handed down in the human genome since the days of sabre-toothed tigers stepped in to fill the mental void. Li grabbed a Kampfpistole Kampfpistole with a with a Panzerwurkorper Panzerwurkorper LP 42 grenade from the arms locker, and swung it towards Sin, firing from the hip. LP 42 grenade from the arms locker, and swung it towards Sin, firing from the hip.

Surely an anti-tank round would finish it, Li hoped.

The armour-piercing grenade streaked across the turbine chamber, leaving a faint smoke trail in its wake. Sin was already moving, however, and Li could see by the direction of the smoke trail that the grenade wasn't running true. He hurled himself to the ground as the grenade slammed into the heat exchanger.

There wasn't that much flame, but the blast was directed in through the casing of the heat exchanger, shattering its structure. A microsecond later, the superheated steam within burst free and the whole block of machinery exploded in a cloud of steam and shrapnel.

Sin was blown clear across the pumping station by a wavefront of steam that was as solid as any white-top in the sea. Dense white clouds of hot vapour billowed out to fill the turbine chamber and Li had barely got to his feet before he began to feel uncomfortably hot. In seconds he was sweating so much that his hands and feet slipped around inside the gloves and boots, while his temples throbbed.

The lights went out with a bang as the vapour shorted them out, but were quickly replaced by red emergency lights. The steam was thicker than any fog Li had ever been in, and its new red tint made him feel even hotter.

He wouldn't have liked to speculate on how hot it was, but even the suit wasn't helping much. What he needed was to get out as quickly as possible. He stumbled in the direction he recalled the door as being. Several other people coalesced out of the swirling steam, all converging on roughly the same area, and he hurried that way himself.

Deafening alarms clanged rapidly in the control room above, while steam rose in a tide that more than covered the windows overlooking the turbine chamber. At once water began condensing on the windows and flowing back down in small streams. The steam didn't thin out at all, however, as the cooled condensation was being constantly replaced by new steam heated by the reactor.

HsienKo darted over to the windows, trying to see what had happened. She made to lean against the gla.s.s, but quickly pulled back the gla.s.s was quite warm. She couldn't see anything through the steam anyway. 'What the h.e.l.l is going on here?' She joined Ying at the wall of dials and meters. Many of the needles were fluctuating wildly, while the rest had either dropped to zero or were rising into red-painted sectors.

Ying pointed to a bank of meters which were rapidly dropping to zero. 'We're losing turbine pressure...'

'To h.e.l.l with that! Both inflow and outflow to the heat exchanger have gone. Radiation levels are rising in the turbine hall and we can't pump coolant into the reactor!' HsienKo's blood chilled. If the reactor couldn't be cooled, far more neutrons than were healthy would build up in the reactor and unbalance the reaction. 'What's our multiplication factor?'

He looked at her, clearly not following her line of questioning. He checked the relevant gauges, making a quick calculation. 'Multiplication factor one point zero five!' He squeaked out the last word in a startled tone.

Everyone in the control room turned at that, their faces all equally pale. HsienKo pointed to the levers. 'Get the control rods in, now. Override the turbine room door controls and keep them locked.'

Ying pointed down. 'But the technicians are trapped in there.'

'So is the radioactive steam. Don't you want to keep it that way?'

Kwok had just finished repairing the damage Sin had done to the lighting cables. Now all he had to do was tell HsienKo what had happened and find out if she knew anything they could do about Sin or how he had turned so insane. He had the unshakeable feeling that the Doctor and/or Yan Cheh must be responsible, and was terrified that something might have happened to her to prevent her from keeping control of Sin.

On the other hand, he had warned her often enough that the Tong's records showed that even Sin's creator couldn't control him in the end, so perhaps the fault was purely internal.

He had almost reached the last ramp up when he heard a distant boom. The ground shook and a sharp crack sent a shower of rock and dust crashing into the tunnel. Kwok dived to shelter as the rumbling died away. When he opened his eyes, the tunnel was blocked. Kwok thought hard. From here he could reach a cave mouth on Sunview Peak. Then he could go round to the Jade Emperor temple and enter the reactor level tunnels through the cave there.

Driven by an adrenalin rush of concern, Kwok ran.

Sin looked around but his surroundings were a uniform bright red, as if he were suspended in bright arterial blood.

Thermographic vision blinded by the hot steam, his targeting system switched to audio, but the whole chamber was filled with a cacophony of bells and screams.

Unable to acquire a target, Sin backtracked the directions and distance he had moved since entering the chamber in order to locate the door. He started moving as soon as the calculations were complete.

Li heaved at the door wheel, but it wouldn't budge.

Presumably someone in the control room above had noticed what was going on and somehow locked it from up there. He looked up, the long window visible as the steam thinned out with height.

There was a steel rail along the middle of the window for people to lean on. If he could manage to knock a hole in the window, he might be able to la.s.so it with a fire-hose and climb up. He still had the Browning, but everything here seemed to be well armoured, so it would be prudent to a.s.sume the gla.s.s was bullet-proof. He also still had a grenade for the Kampfpistole Kampfpistole, however. Considering what one of them had done to the heat exchanger, bullet-proof gla.s.s should be no obstacle.

He ran back towards the middle of the chamber, using the visible windows as a guide. So far, none of the panicked technicians seemed to have thought of looking up; they were all crowding round the door controls as he left them.

Sin still couldn't see but knew that he was approaching the door, as the calculations he had made measured out the route and distance precisely. He was not expecting, therefore, to b.u.mp into something resilient but yielding, which he recognized as a human standing in the way.

Delighted by this, Sin clutched at the human's suit and swung his knife-hand back to strike. The hand hit another human. Sin couldn't suppress a l.u.s.tful giggle as he plunged into the feast around him.

Li heard the screams begin at the door and realized that Sin had found someone new to occupy himself with. He didn't care; they were only gangsters anyway. He had fitted the second grenade onto the Kampfpistole Kampfpistole by now, and aimed it at the window above, bracing the gun on his free hand. He tried to judge the best angle to get the grenade to hit the gla.s.s square-on; he didn't want it to hit at an angle and richochet off into the turbine chamber. Telling himself that Matsu would have approved of his efficiency, Li fired. by now, and aimed it at the window above, bracing the gun on his free hand. He tried to judge the best angle to get the grenade to hit the gla.s.s square-on; he didn't want it to hit at an angle and richochet off into the turbine chamber. Telling himself that Matsu would have approved of his efficiency, Li fired.

The control rods had reached the surface of the heavy water and were beginning to edge their way down into the nuclear pile itself. 'Multiplication factor now one point two,' Ying reported, 'but the rate of increase is slowing.'

HsienKo nodded her acknowledgement. The control rods were working effectively already. Once they were fully in, the reaction would slow and the multiplication rate would drop below one. Then they would be safe and could set about finding out what had gone wrong.

Her heart began to resume a more normal rhythm after the past few minutes of fluttering and she relaxed slightly. This was only a delay.

Without warning, one pane of the observation window overlooking the clouded turbine chamber exploded inwards in a cloud of fragmented gla.s.s, as a metal egg sailed through it and landed by the levers opposite. HsienKo ducked beneath her desk instantly, but before she could put voice to the warning in her mind, the grenade went off.

The levers controlling the placement of the control rods were shattered, while a spray of shrapnel peppered the instruments lining the walls. The technician manning the levers was blasted to b.l.o.o.d.y pulp, while Ying crashed into an instrument bank. The instruments' shattered wiring sparked and burst into flame. Ying quivered stiffly, screaming as his hair started to singe and his skin blacken, and then toppled to the ground.

Highly radioactive steam poured in through the shattered gla.s.s and the surviving technicians, most bleeding from minor shrapnel cuts, bolted for the doors. HsienKo knew she should leave too and was starting to follow them out, until she noticed the view through the more thickly armoured gla.s.s into the reactor cave.

The control rods had jerked to a halt, no more than about ten per cent into their slots in the pile. Despite her green eyes, HsienKo didn't feel remotely harmonious at the moment.

Terror flooded through her, but she knew she couldn't give into it. The radiation was bad enough, but she had to try to prevent the whole mountain going up, which it would when the multiplication factor reached critical.

She s.n.a.t.c.hed a protective suit off the rack by the door, and hastily clambered into it.

Li had given a brief laugh of delight when the window shattered, and ran to the wall below. The steam was already thinning out as it escaped through the control room. As a result, he had no difficulty in finding a reel of hose at a fire-point and unrolling it. It took three attempts to get the weight of the bra.s.s nozzle to wrap the end of the hose around the rail when thrown.

Li was surprised that no one else had joined him to climb up not that it mattered until he looked towards the door.

The bloodied Sin was furiously carving up the back of the last technician, who was clawing weakly at the doors. A number of torn and mutilated bodies lay around them.

Li felt his fear return; it would be only moments before Sin noticed him. He tugged on the hose to test its resistance to weight, then quickly hauled himself up. The rail provided a good handhold with which to climb over into the control room. Most of the instruments there were sparking and smoking, while the traitorous Ying lay dead at the base of them. Li felt blessed by the G.o.ds obviously his grenade had executed the traitor.

The only live person in the room was a suited figure working furiously at the shattered levers opposite the window he had entered, but Li decided not to bother with whoever it was. He had clearly destroyed their plans, so what difference did it make. The figure didn't look round as he left.

Romana had never seen such panic since Gallifrey itself had been invaded not so long ago. Guards and technicians were hurtling through the tunnels aimlessly, while alarm bells rang.

Whatever was wrong, it didn't inspire much confidence.

She and the Doctor headed in the direction from which the fleeing men were coming, since that would most likely be the control room. 'The reactor?' she asked.

'Probably. It's not a very sophisticated model.'

Romana saw a familiar face through the visor of a limping figure. 'Li!'

Li paused and the Doctor grabbed his shoulders. 'What happened?'

'I blew the heat exchanger to the turbines. Whatever they're planning, it's over.'

The Doctor stared. 'What?' He thrust an accusing finger at Li. 'Do you have any idea of what you've done?'

'I've prevented these anarchists from disrupting the order promised by j.a.pan.'

'No; you've turned this mountain into a bomb big enough to erase Shangdong province from the face of the Earth! With no coolant, the reactor will overheat, go critical and boom!'

Li at least had the sense to blanch. The Doctor shook his head. 'I have to get there.'

Romana wondered how long ago this had started. 'We might not be in time.'

'We have to try. Get out of here,' he told Li.

The Doctor and Romana disappeared towards the control room. Li wasn't bothered; he would be rid of that troublesome pair as well. He started off towards the exit to the surface and almost immediately ran into a platoon of guards. They didn't point their guns at him, however. Rather, they looked confused and scared.

So much the better, Li thought. 'What happened?' several of them asked.

Li was about to deny any knowledge when a better idea struck him. Here was an opportunity to finish off all those anarchists once and for all. 'HsienKo betrayed us to the Doctor and the girl. She went crazy and started wrecking the control room. Spread the word.'

The guards exchanged incredulous looks, but most of them seemed to take it in. Li knew that being dressed in the technician's suit would help convince them he was an eyewitness. As they started checking their guns, Li moved off again before they could ask him any awkward questions.

Before long he met another group of Tong soldiers.

'Quick,' he shouted, 'some of the guards have turned they've wrecked everything...'