'Irreversibly to you, perhaps. The technology of these creatures predates yours by millions of years. Believe me, if they intend to fire these missiles of yours, they'll find a means to do so!'

'They simply won't have time, Doctor. As soon as I leave in the escape pod, this Base will be attacked by the forces of the East Bloc. Since the Base is helpless, everything in it, the creatures as well, will be destroyed.'

Suddenly Maddox appeared in the doorway to the computer bay. He was wild-eyed and hysterical, but he was sane again. For the time being at least, the savage cut-off from Nilson's device had cancelled the conditioning.

He waved the blaster at Nilson. 'You murdering traitor!

You made me kill Karina. Now you're going to die.'

Nilson's hand dived into his pocket and operated the control device. Maddox swayed on his feet, desperately trying to bring the blaster to bear on Nilson.

'I'm sorry Maddox,' said Nilson softly. 'Your usefulness is at an end.' He turned the control device up to its highest frequency. Maddox's face twisted in agony, his body stiffened, and he crashed to the floor like a felled tree, his brain burned out.

Preston ran to the body. She looked up. 'He's dead.'

'Leave him,' ordered Nilson. 'Over here!'

For a moment the Doctor was forgotten. Suddenly he flung himself across the room at Nilson, knocking the blaster aside. Nilson clubbed him savagely across the head with the control device in his left hand. The Doctor staggered and fell. Before he could recover, Nilson grabbed Tegan, holding her in front of him as a s.h.i.+eld.

'If any of you try to follow me, she dies,' he said matter-of-factly, and backed away from the Bridge.

Turlough, Bulic and a surviving guard were in full retreat by now. They dashed along the corridor, turned a corner and then found themselves facing a squad of Sea Devils.

The guard raised his weapon to fire and was immediately shot down.

Turlough stared for a moment in horror at the bulbous-eyed creatures and then threw down his weapon.

'Surrender, you fool,' he hissed. 'Throw down your blaster.'

Reluctantly Bulic obeyed.

The Doctor picked himself up and rubbed his aching head.

Lieutenant Preston was checking the computer.

Vorshak was listening to a report on his communicator.

'There's very little we can do, sir,' an anguished voice was saying. 'The Sea Devils have just breached the Bridge perimeter defences.'

'What about Bulic, and the boy Turlough?'

'No one's seen them, Commander. They must be dead or taken.'

Vorshak said, 'Doctor, I'm sorry...'

The Doctor picked up Karina's blaster from beside Maddox's body. 'I'm going after Nilson. Where's the entrance to the dock for the escape pod?'

Vorshak led him to a wall-plan of the Base. 'Here, Doctor.' His finger indicated a point on the map. 'The quickest way is along here, and then down here.'

With one quick glance the Doctor committed the map to memory and hurried on his way.

Sauvix strode proudly up to the Silurians. 'Your orders have been obeyed, Icthar. The way to the Bridge is clear.'

Turlough and Bulic had been herded into what looked like an empty store-room, with a Sea Devil guard at the door.

Turlough was by no means sure why they had been left alive and he had little confidence in this state of things continuing. 'We've got to get out of here, Bulic.'

Bulic, who had fought so hard and so long, seemed suddenly to have given up. He was slumped disconsolately in one corner. 'What's the point? Where could we go? The Sea Devils are all over the Base.'

Turlough was no hero, but he had the determination of a born survivor. 'We must get to the TARDIS. At least we'd be safe there, and if the Doctor can get there, we can still escape.'

There was a little window in the door. Through it Turlough could see their Sea Devil guard. He looked very alert.

Nilson was beginning to wish he'd picked a more docile hostage. His progress had been considerably slowed by the fact that Tegan had struggled every foot of the way, and she was struggling still. Nilson would cheerfully have killed her except for her possible value as a hostage. Once he reached the escape pod...

He shook her savagely. 'Be still, woman!'

He dragged her around the corner, and they found themselves looking at the p.r.o.ne body of the Myrka.

Intrigued despite his haste, Nilson paused for a second to examine the UV convertor. 'Ingenious! A pity all the Doctor's efforts were to no avail.'

'You haven't got away yet,' said Tegan spiritedly.

Nilson gripped her shoulder savagely, urging her onwards. Suddenly Tegan grabbed his arm and pulled him off balance. He lunged towards her. Tegan jumped aside, tripping him up. He fell, just as the Doctor ran around the corner.

'Tegan,' called the Doctor running forward.

'Stay where you are, Doctor,' shouted Nilson. He was still on the floor, but the blaster in his hand was levelled unerringly at Tegan. 'You were foolish to follow me, Doctor. Now drop the weapon, or the girl dies here and now.'

The Doctor tossed his blaster to the floor he'd never liked carrying weapons anyway. 'Let Tegan go, Nilson.

She's no use to you now.'

Nilson was scrambling to his feet, the blaster wavering between the Doctor and Tegan.

'Killing us won't make your escape any easier,' said the Doctor calmly. 'Fire now and you could bring every Sea Devil in the area running.'

Nilson said furiously, 'I am prepared to take that risk, Doctor.'

'Make a wish, Tegan,' said the Doctor calmly. Nilson levelled the weapon at the Doctor's head. 'Goodbye, Doctor.'

'Goodbye,' said the Doctor.

Flinging himself to one side, he threw the switch on the UV convertor, filling the corridor with intolerable white light. Nilson screamed, covering his eyes. The Doctor jumped up, eyes half-closed against the glare.

Tegan had guessed what was going to happen and was standing there with her eyes protected by an upflung arm.

The Doctor grabbed her other arm to pull her away.

Nilson fired wildly, missing by several feet, just as the Sea Devils stalked around the corner. Nilson stood staring at them, the blaster in his hand. Instantly the Sea Devils shot him down.

They advanced on the Doctor and Tegan.

10.

Captured The Doctor stepped forward to meet the advancing Sea Devils. 'How do you do? Haven't we met before? I'm the Doctor!'

There was no reply. The Doctor switched off the UV convertor and the lighting returned to normal. 'That's better. Now, take me to your leader!'

One of the Sea Devils made a gesture with the strangely shaped weapon in its hand.

The Doctor and Tegan moved back down the corridor, the Sea Devils behind them.

Turlough paced nervously up and down the bare metal room, looking round for some way of escape. He looked through the little window in the door. The Sea Devil guard was standing in the corridor with his back to them no real chance that way.

Turlough spotted a metal grille high up in the wall. He looked down at Bulic, still slumped in his corner and pointed. 'What's that up there?'

'Must be a ventilation shaft.'

'Well, well, well,' said Turlough softly. 'Come on, up you get. I need your help.'

The Doctor and Tegan were marched back onto the Bridge. It was clear that the Base was now in the invaders'

hands. Vorshak stood by the command console, flanked by two brown-skinned alien figures with crested heads Silurians!

The Doctor looked at the blunter, more rounded heads of his Sea Devil guards, at the crest that swept backwards and downwards from the reptilian snouts.

Silurians and Sea Devils, thought the Doctor. He had encountered both before, but separately. Now they had resumed their old alliance. It was doubtful if the human race had ever faced more formidable enemies.

The leader of the Sea Devil guards raised his hand in salute. 'Greetings, Icthar; My Warriors have now captured the reactor room.'

The taller of the Silurians said, 'Excellent, Sauvix. You have done well.'

'All right, so you've won,' said Vorshak savagely. 'You might at least allow my crew members to surrender, rather than just hunt them down.'

'It is they who insist on fighting,' said Icthar blandly.

He sounded, thought the Doctor, as though it made little difference whether the crew of the Base surrendered or were shot down, as if it would all come to the same thing in the end.

Another Silurian emerged from the computer bay. 'The damage has been a.s.sessed, Icthar. The computer can be returned to normal functioning.'

'Excellent,' said the tall Silurian again. 'See that the work is completed with all speed, Tarpok.'

The Silurian returned to the computer bay.

'Icthar,' muttered the Doctor. 'Icthar! I recognise that name.'

Tegan looked at him in amazement. 'You know know that that thing? ' '

'I think so. I thought he'd been killed with the others.'

Icthar seemed to notice the Doctor and Tegan for the first time. 'Remove these prisoners from the Bridge,' he ordered.

The Doctor stepped forward. 'Wait, Icthar. We are known to each other.'

For a moment the huge Silurian eyes were turned upon the Doctor, then: 'You are mistaken,' said Icthar. 'Take him away.'

'No, wait,' shouted the Doctor. 'I am a Time Lord, Icthar, my race changes, regenerates. In an earlier incarnation you knew me as the Doctor.'

' You You are the Doctor?' said Icthar slowly. 'You can prove what you say?' are the Doctor?' said Icthar slowly. 'You can prove what you say?'

'When we last met over a hundred years ago, I came to the underground base of your people, I tried to mediate, to make peace between you and the humans.'

The Doctor talked on, recalling the events of that crisis of long ago. He remembered the wise old leader he had known as the Old Silurian, the arrogantly hostile Young Silurian.

Icthar had been the third member of the ruling group.

He had said little and the Doctor had always felt that he was poised between the two opposing factions.

'You were one of the n.o.ble Silurian Triad,' concluded the Doctor. 'I feared you had all been killed '

The Doctor broke off, remembering that the peace negotiations had broken down, ending in disaster. Without the Doctor's knowledge or consent, the Brigadier had set off charges that entombed the Silurians in their underground base.

The Doctor looked at the Sea Devils remembering their earlier attack on the humans, encouraged by the Master.

There too the Doctor's peacemaking efforts had met with small success. They had been sabotaged by a treacherous attack ordered by an ambitious human politician. The Doctor and the Master had escaped from the Sea Devils'

undersea base and the Doctor had been forced to ensure that the base blew up behind them.

'So you are the Doctor,' said Icthar finally. 'You betrayed us, Doctor. You have much to answer for.'

'Twice I have tried in vain to make peace between your people and the human race,' admitted the Doctor. 'Twice I have failed, thanks to the self-destructive efforts of the extremists on both sides. Must it happen again? Please, Icthar, may we speak?'