'What?'

'It's a nervous reaction to the neurolectrin addiction.'

'He needs another fix?'

The Doctor nodded and fumbled through his pockets. 'I think I've brought a spare injector.'

'I thought you said he couldn't have any more?'

'We can't leave him like this. Hold him steady.' The Doctor produced a neurolectrin injector and applied it swiftly to Oldeman's neck. Within moments the professor began to calm down, the spasms subsiding to a slight tremor. The Doctor shook his head and discarded the empty injector. 'I shouldn't have brought him with us.'

'It's too late for second thoughts, Doctor,' Tegan said.

Nyssa walked into the domed chamber and staggered against the wall, weak at the knees. The sight of the great pit at the centre of the room, full of its dreadful black ooze, filled her with terror. The throbbing green glow from the snakes lining the ceiling made her feel nauseous. Her stomach churned.

Cadwell stepped into the chamber. He was looking less confident now.

His eyes were wide with fear and his skin looked waxy in the putrid luminescence.

'It's here,' he said in a hoa.r.s.e whisper, staring at the black pit.

Nyssa tried to press herself into the rock wall, keeping as far away from the deadly well as possible. The dark slime it contained was now bubbling, the sound echoing around the chamber like distant laughter.

Cadwell wiped a hand down his face, as if trying to gather his wits.

Suddenly he pulled the bag from his shoulder and opened it. He pulled out a large plastic container and set it down on the floor beside the pit.

'What are you doing?' Nyssa asked.

Cadwell glanced up at her and smirked. 'Fulfilling a promise,' he said.

He unscrewed the lid of the jar.

Nyssa felt as though she was about to burst: the black tar in the pit was calling out to the dark blood oozing through her veins.

Somewhere inside her she felt as though the black slime was rising in her gut, bubbling thickly and making her gag.

'That's far enough, Cadwell,' said the Doctor, stepping into the chamber behind him.

Cadwell jerked around in surprise. 'You!'

Nyssa stared mutely at the Doctor. He stood framed in the entrance, Tegan and Ravus Oldeman just behind him.

'Stop what you're doing and stand up slowly,' the Doctor instructed Cadwell.

Cadwell climbed to his feet with a murderous look in his eyes. 'You blundering fool, Doctor! Why don't you just leave now, while you still can?'

'I was about to say exactly that to you,' the Doctor said.

'Come over here, Nyssa.'

Nyssa started forward, and Cadwell took that opportunity to strike: he s.n.a.t.c.hed her arm as she pa.s.sed him and jammed his gun into the side of her head.

'Don't be stupid!' cried the Doctor.

Cadwell leered at him and gave a harsh laugh. 'I was about to say exactly that to you, you, Doctor! Now get back or I'll blow Nyssa's brains out. Doctor! Now get back or I'll blow Nyssa's brains out.

I don't need her any more.'

But Nyssa squirmed in his grip and bit down on his hand with enough force to draw blood. Cadwell howled and the gun went off, missing Nyssa's head by a fraction and blasting out a chunk of rock from the wall.

The Doctor leapt forward, tackling Cadwell and bringing him down heavily. They hit the inclined floor and rolled towards the black pit pit Cadwell's gun clattered away and Tegan s.n.a.t.c.hed it up. Cadwell's gun clattered away and Tegan s.n.a.t.c.hed it up.

Cadwell stuck his elbow into the Doctor's throat and heaved. The Doctor spun away and the two of them scrambled to their feet. But the Consortium man was evidently trained in unarmed combat: a barrage of tightly controlled kicks and punches soon had the Doctor reeling, every blow connecting despite his best efforts to block and parry.

Finally Cadwell kicked out and the Doctor lurched back towards the pit, his nose and lips bleeding.

'Stop it!' shouted Tegan, aiming the automatic. 'I'll shoot!'

Cadwell ignored her. He took one long stride towards the Doctor and grabbed him by the lapels of his frock-coat.

Cadwell's face was a mask of fierce concentration as he prepared to finish the job.

'I said stop it!' Tegan shrieked.

Oblivious, Cadwell slammed his forehead into the Doctor's face and then hurled him towards Tegan, spoiling her aim.

Nyssa grabbed Cadwell and pulled him backwards.

There were black tears running from her eyes as as she threw Cadwell heavily against the wall. His legs gave out and he slid to the floor. she threw Cadwell heavily against the wall. His legs gave out and he slid to the floor.

For a second everything seemed to stop.

'I've just been beaten up,' the Doctor mumbled in disbelief, climbing shakily to his feet. He gently touched his split lip and winced.

'Never mind that,' Tegan said. 'Nyssa's just saved your life.'

The Doctor blinked. 'Nyssa?'

Tegan pointed to where their friend was standing by the pit. Silas Cadwell lay at her feet, groaning senselessly. Nyssa looked up from his inert body and glared at the Doctor and Tegan. Her eyes were black spots swimming in blood.

'Nyssa?' said the Doctor quietly, stepping towards her.

'What's wrong with her?' Tegan asked, suddenly panic-stricken. She still held Cadwell's gun but she didn't know where to aim it.

Nyssa was just standing there, right at the edge of the pit. Behind her the dark slime welled up and burst with huge, thick bubbles. A revolting, stench filled the air.

'Nyssa, listen to me,' the Doctor said. His voice was full of desperation. 'It doesn't have to be like this. You can fight it!'

'I can't.' she croaked.

Tegan gripped the Doctor's sleeve. 'What's the matter with her?'

'It's the Dark. It's securing its bridgehead in her mind.

Taking over.'

'We've got to stop it!'

'Yes. I'm open to suggestions.'

'Not... yet... complete...' yet... complete...' gurgled Nyssa helplessly. She swayed on the edge of the pit, and looked as if she could topple backwards into it at any moment. 'Help... me...' gurgled Nyssa helplessly. She swayed on the edge of the pit, and looked as if she could topple backwards into it at any moment. 'Help... me...'

'Doctor, do something!' Tegan urged. 'She's begging for help!'

'Is she?' the Doctor said. 'Or is it the Dark, begging through her?'

Tegan looked again at Nyssa. Her eyes had rolled up into her head, the tears forming two black streaks down her face. Her mouth fell open but no words came out.

Suddenly Ravus Oldeman let out a sharp cry. They all turned to see him stagger forward as something grabbed him from behind.

Something the colour of fresh meat.

'Get back!' ordered the Doctor, pushing Tegan and Vinson away as the Bloodhunter lifted Oldeman into the fetid air and carried him bodily towards the pit. Oldeman squirmed in its grip and tried to scream, but it was too late. The Bloodhunter had dug its powerful, clawed forgers deep into the man's throat, cutting off his air supply. Then, with one sudden motion, the creature ripped open Oldeman's neck and a fountain of blood emerged with his last, convulsive breath.

The blood spattered across the floor and immediately began to trickle down towards the pit.

The creature dropped Oldeman's body without ceremony. Oldeman lay where he fell, emitting terrible gasps and gurgles as his life-blood gushed from him. With wide, pain-filled eyes he watched the scarlet river running away from him, down the slope and into the pit. The blood streamed over the edge and disappeared into the blackness.

Nyssa let out a sigh of relief.

A final tremor pa.s.sed through Ravus Oldeman's body and he lay still.

The light faded from his eyes.

The Doctor stared at Oldeman's corpse, utterly aghast.

'I am complete,' whispered Nyssa. whispered Nyssa.

Immediately the chamber darkened and everyone instinctively looked up at the ceiling, where the green snakes were growing dimmer by the second.

'They're dying,' realised Tegan.

The light began to fade. The Doctor appeared to be paralysed, hip eyes wide and gla.s.sy as as the appalling truth hit home. The Dark's being reborn,' he said. 'We've got to get away from here!' the appalling truth hit home. The Dark's being reborn,' he said. 'We've got to get away from here!'

Tegan said, 'Wait, Doctor! What about Nyssa?'

They looked back at her: Nyssa with her head thrown back, a terrible gurgle building in her throat. Suddenly thick black liquid streamed from her mouth and nose and she staggered forward. She collapsed onto her hands and knees, shaking. The dark bile spread out beneath her, seemingly with a life of its own, then began to run back down the slope towards the pit.

The Doctor was ashen-faced. He gripped Tegan's arms, trying to push her towards the exit, but she refused to move.

'We can't just leave her!' she shouted.

Then something huge and dark erupted from the centre of the pit. It blotted out the sickly remains of the light and filled the chamber with a freezing, impenetrable blackness.

Chapter Seventeen.

Tegan felt herself pushed out into the light. Hands grabbed her and pulled her forwards. She was outside the crypt again, at the edge of the stalact.i.te forest, with the Adamantium Adamantium crewmen. Vinson was standing over her with a powerful torch. crewmen. Vinson was standing over her with a powerful torch.

'What's going on?' he asked.

'We've got to get out of here!' Tegan told him. 'Someone else is coming,' said one of the Adamantium Adamantium men. They turned their flashlights towards the tunnel entrance and Silas Cadwell staggered out, his face drawn and white. Vinson's blaster snapped up to cover him. 'Hold it right there, sir!' men. They turned their flashlights towards the tunnel entrance and Silas Cadwell staggered out, his face drawn and white. Vinson's blaster snapped up to cover him. 'Hold it right there, sir!'

'Get out!' Cadwell screamed at him. 'Get back! Run!'

Vinson lowered his gun but stayed put. Cadwell clearly wasn't armed. In fact, he seemed to be terrified.

'I'd do as he says if I were you,' said another voice.

Tegan turned to see the Doctor emerging from the crypt entrance, Nyssa slung over one shoulder in a fireman's lift.

'Run for your lives!' he gasped, almost stumbling to the ground with Nyssa.

The instruction carried the weight of genuine fear: every Consortium man turned and sprinted for the grey forest, with the exception of Vinson. 'Here, let me help,' he said, tossing his flashlight to Tegan and heaving Nyssa to her feet. He slung one limp arm over his shoulders, and, with the combined effort of the Doctor, carried Nyssa away from the crypt.