'It must gain power via a small transmitter from the central power unit. We don't want any accidents.'

'It could be a mock-up-like the Cyberman,' said Kaftan.

'We'll soon know,' said Klieg. 'Turn off the power. The switch on the right of that board.'

Kaftan clicked over a switch. 'All the sequences show negative,' she said quietly.

'Good,' said Klieg.

He put his hand into his side pocket and took out a set of jeweller's tools. Kaftan watched while he began to dismantle the weapon. Skilfully he worked out where each separate part must be, unscrewed it and placed it gently on the metal floor. It was a beautiful piece of design, made of better metal alloys than anything they had yet seen on Earth.

'There is nothing wrong with this,' said Klieg. 'Now, they will have to listen to us.'

'The Cybermats are ready.'

'Stand clear,' said the Controller.

The Cybermats were arrayed in a horseshoe round the body of Toberman, their antennae pointing towards him. The Cybermen stood watching.

'Now,' said the Controller's level but precise voice. He turned the control k.n.o.b.

There was a low buzzing noise, a whine, rising slowly to a higher and higher pitch. Nothing moved except the antennae on the Cybermats. They started moving forward towards the giant lying in front of them.

'Excellent!' Klieg was saying. 'A small X-ray laser, I'd guess.'

He took aim with the Cybergun, pointing it at the metal panel on the other side of the room. Kaftan moved back nervously and waited.

Klieg pressed the trigger b.u.t.ton and, with a flash, smoke began to come out of the metal panel. With the trigger pressed, he burned a neat circle in the panel. A round piece of metal clattered forward on to the floor.

'Yes! A laser! Cuts metal, drills through anything we want it to, my dear Kaftan,' he smirked, the gun in his hand giving him the power he knew he had to have.

'What are you going to do now?' asked Kaftan.

'Take command of course,' said Klieg. 'What do you. think?

With this, we shall be able to deal with those people in there.'

Behind him was the hole torn in the metal by the laser gun.' Up through it came the chill wind from the Cybercaverns, and creeping up towards it came the first of a swarm of something else: the first of the reprogrammed Cybermats.

'Never mind about the others,' said Kaftan. 'The important thing for us is to command the Cybermen.'

'Er... yes... I know,' said Klieg. 'But...'

Even with the gun in his hand, he now looked anything but the arrogant conqueror.

'Isn't it, Eric?' insisted Kaftan's clear voice.

'You haven't been down there,' he muttered. 'You haven't seen those... vile things.'

He shivered.

'You're not scared, are you?'

'We have completely underestimated their power,' said Klieg, trying to convey to her some slight inkling of the horror that still waited below them in the chill cavern.

'But this time we have the power,' said Kaftan. 'At least, you do.'

Klieg didn't understand her.

'The gun, Eric. The gun. You have the Cybermen's own weapon. This laser. You can turn it against them. Now they will have to obey,' she went on, her eyes shining. 'If they refuse, we shall destroy the opening device and seal them up in their tomb for ever.'

Klieg looked at her, understanding, full of arrogance again.

'Do you understand?' asked Kaftan.

'Yes, you are right. I am invulnerable with this,' said Klieg. 'I shall be Master of the Cybermen.'

'Come on!' said Kaftan briskly. 'Let's deal with the others.'

She moved towards the door, but Klieg was not following her.

She turned around.

'Eric?' she said.

'Master,' he said, 'the supreme moment of my life.'

She looked at him hard. But he stood still, a strange fixed expression on his face.

'... The supreme moment of my life,' he repeated. 'It was logical that it should happen this way.'

'Eric, we have work to do,' she said firmly.

'Yes, of course,' he said, rousing himself. 'But hardly work-'

A slow smile spread over his features, different from anything she had seen on his face before, a strange self-satisfied grin, but dangerous, blind...

'... More of a pleasure.'

'A what?' asked Kaftan.

'A pleasure,' said Klieg. 'When I think the moment is right to turn this gun on that Doctor and his companions.' He smiled again.

'The rest are of no account,' he said with a casualness that would have done credit to a Cyberman, 'but the Doctor...' He licked his lips as if his mouth was dry with excitement. 'He will make a most precise target.'

Kaftan looked at him again, worried over this new Eric Klieg, then shrugged.Perhaps his mood would pa.s.s. On the floor, unseen, the small silver creature crept towards them, pointing its antennae towards the two logicians.

Down in the cavern Toberman, now awake, watched anxiously as the Cybermats stopped three inches away from his head and reared up to make their fatal leap.

'Enough!' said the Controller. 'These humanoids are not like us.

They still have fear.'

He switched the control back and the three Cybermats subsided on to the floor.

'Place the Cybermats on the runway,' said the Controller, and the Cybermen cautiously picked up the virulent creatures, placed them on three platforms at the back of their cupboard and opened trap doors in the wall. They looked up three small chutes and made sure they were clear. Each chute, leading up to the top level, where the humans were, was a clear runway for the Cybermats.

The Controller stood by the control panel. He turned the control again.

'The Cybermats will attack!' he said.

A humming sound began and, their red eyes flashing, the silver scorpions moved up the chutes.

In the control room upstairs the exhausted humans were asleep. Victoria,. whose watch it was, was nodding off, trying vainly to keep awake, but the others-Jamie, the Doctor, Parry and Callum were deep asleep.

Suddenly the Doctor started awake. He blinked and stretched, then noticed Victoria still sitting up but nodding forward, her long hair round her like a cape.

'Hey, why didn't you wake me?' asked the Doctor. 'I'm on your side, remember?' He smiled at her with his rare kind smile, a smile so kind that it seemed to take all the sadness there was inside it and still come out as a smile.

'I ought to have been on watch half an hour ago,' he said.

'I thought you should rest,' said Victoria primly.

'Why me?'

'Oh, well-no reason really,' stumbled Victoria, embarra.s.sed.

The Doctor looked at her, puzzled, then his face broke suddenly into a smile.

'Oh, I think I know. Was it because I'm... '

'Well, if you really are four hundred and fifty years old, you must need a great deal of sleep,' said Victoria in her best governess voice.

'Very considerate of you,' said the Doctor. 'But I'm really quite lively actually, all things considered.'

He looked at her affectionately. She was quite a girl, Victoria.

Plucked suddenly from her comfortable home in the Victorian age, to cope alone with people and places centuries ahead, she kept her affections and used her intelligence remarkably well.

He sat beside her.

'Are you happy with us, Victoria?' he asked.

'Yes, I am. At least, I would be if only my father... were still alive.'

'I know. I know,' murmured the Doctor.

'I wonder what he would have thought if he could just see me now,' she murmured.

'You must be missing him very much.'

'It's when I close my eyes,' she said, turning to him and looking at him earnestly with her grave, blue eyes. 'I think I can still see him standing there-before those awful... Dalek creatures came to the house.'

She tried not to think about that and the way the Daleks had killed him. Instead, she had trained herself to remember evenings sitting together in front of the fire and the way he laughed, saying, 'Toria! Listen to this!' while reading out something that amused him in his book.

'He was such a kind man, you know,' she said to the Doctor. 'I shall never forget him. Never.'

'Of course, you won't,' he said softly. 'But the memory of him won't always be a sad one.'

'I think it will,' said Victoria.

'It must be difficult for you to see what I mean,' she said wisely. 'I suppose, because you're so ancient. I mean old... You probably can't remember your family.'

'Oh, but I can,' and the Doctor again gave her that smile that was full of everything. 'I can, when I want to, and that's the point, really. I have to really want to bring them back in front of my eyes- the rest of the time they sleep in my mind and I forget.' He looked at her compa.s.sionately. 'So will you.'

Victoria looked doubtful.

'You will, you know,' he insisted. 'You'll find there is so much else to think about-to remember. Our lives are different from everybody else's, that's the exciting thing,' he said. 'n.o.body in the universe, in the whole universe, can do what we're doing, be what we are. n.o.body.' He looked at her young intelligent face.

'Now, get some sleep and leave this poor old man to try and keep awake,' and he smiled at her again, but this time with his old ironical smile, the casual Doctor again.

Victoria lay down and let the sleep she had been fighting roll over her, comforted as she always was by the Doctor's gentle philosophy.

So slowly, it was not perceptible by a human, the Cybermat pushed open the top door of its chute, well concealed at the foot of the Cybermen bas-reliefs, and the supple, silvery body crept like a rat into the room. Then another, and a third. The Doctor sat still, his thoughts far away, perceiving no danger-until something touched.

his foot. He started, looked down, rose up and jumped back out of reach.

'Jamie!' he shouted. 'Victoria! Callum! Wake up!'