The Doctor's head was slumped forward, his eyes open. 'He seemed to faint when you came through that door.'

Ben bent down and snapped his fingers in front of the Doctor's face. 'Hey, Doc.

Come on. Wakey wakey. It's all right now-it's all over.'

His words seemed to rouse the Doctor. He slowly stirred and raised his eyebrows.

'What?... What did you say? It's all over? Is that what you said?'

He shook his head. His eyes gazed past Ben-it was as though he was seeing ahead a great way into time. 'That's where you're wrong, my boy. It isn't over. It's not over by a long way.'

'What are you on about, Doctor?' said Ben.

For answer, the Doctor stood up. 'We must get back to the TARDIS immediately.'

'Are you all right, Doctor?' said Polly.

The Doctor shook off her supporting arm. 'We must go now.'

'What's the hurry?' asked Ben. 'Mondas has broken up. There's nothing more to fear from the Cybermen. Aren't we going to go back to the South Pole base to say good-bye?'

The Doctor shook his head impatiently. 'No, no. We must go, I say.' The Doctor drew his borrowed parka around him and hurried out through the door.

'What's happened to him?' Polly looked at Ben.

'Search me ! He doesn't seem to know where he is.'

Polly shivered. 'Please Ben, let's get out of here.'

They trudged across towards the TARDIS, now half snowed up. The wind had died; the moon was casting a luminous glow over the gleaming Polar wastes.

Polly paused for a minute. Ahead of them they could see the Doctor trudging through the last few yards of snow to the door of the TARDIS. Polly looked around. The drifting snow had completely covered the dead bodies of the Cybermen. The Polar scene had an incredible purity and innocence-like a dream landscape.

'It's beautiful here,' said Polly. 'I don't suppose we'll ever see it again.'

'We'll become part of it if we don't keep moving! Come on, d.u.c.h.ess.'

He grabbed Polly's arm and led her on towards the TARDIS. The Doctor had already opened the door and walked inside.

As Ben and Polly entered and began stripping off their furs, there was no sign of the Doctor. They went through into the TARDIS' equipment room, and hung up their heavy International s.p.a.ce Control parkas.

'We should really return these, you know,' said Polly, practical as ever.

Ben shrugged his shoulders. 'I reckon we've earned them. Anyway, they've got ours ! ' His face looked set and preoccupied. Polly peered at him anxiously.

'Aren't you glad to be back inside here?' said Polly. 'I never thought I'd get so used to this place that I'd call it home! But, after the last few hours, it seems like paradise.'

She turned to walk out into the main TARDIS Control room-but Ben stopped her: 'Half a mo', d.u.c.h.ess. It's the Doctor. I don't think he'll last much longer.'

Polly turned a little pale. 'What do you mean?'

'Haven't you noticed? He's put on a score of years during the last few hours. How old did he say he was once? Hundreds of years? Looking at him now, I'm inclined to believe every day of it!'

Polly shook her head despairingly. 'What can we do?'

'That's just it,' said Ben. 'There's not much we can do, except...'

Suddenly, a long wailing cry came from the control room. The voice was not the Doctor's.

They rushed out.

They hurried over to a long couch-like arrangement with a folding metal cover over it. The use of it had never been fully explained to them. The Doctor had simply told them that it compressed sleep. The cry seemed to be coming from this apparatus.

'How does it work?' said Polly, struggling with the catch.

Ben pulled back her hand. 'Let me, d.u.c.h.ess.' He turned and pulled down a lever standing beside the apparatus. The hood slid silently back to reveal the long stretcher-like couch.

To their relief, they saw the Doctor's familiar cloak and body. The corner of the long cloak was drawn over his face.

'He's been sleeping,' said Polly, relieved. 'Using the sleeping compressor.'

But Ben was staring at something.

'Hold on, Poll. Look!' He pointed at the Doctor's hands, which were folded over his chest. The Doctor had long, thin, sensitive, rather boney hands. Of late, they had become white and transparent, the blue veins showing through the skin : the hands of a very old man.

But Ben was pointing in amazement at two completely different ones. They were shorter, thicker set, reddish-the hands of a much younger man.

Polly drew back, hand to mouth. 'Oh Ben! Do you think...'

'We'll see,' said Ben grimly. He reached forward gingerly and pulled back the edge of the cloak. The face under the cloak was not the Doctor's. It was the face of a much younger man-a man in his early forties. The Doctor's long, silver locks had been replaced by short dark hair, and the newcomer had a swarthy, almost gypsy, appearance.

As Ben and Polly drew back aghast, the man slowly opened his eyes and turned to looked at them.

'h.e.l.lo,' he said. His eyes were blue-green-like the sea. Although friendly, they had an elusive, slightly mocking quality. 'You must be Ben and Polly?' he continued.

Ben nodded.

'And who are you?' asked Polly boldly.

The man stretched himself and swung his legs over the edge of the cradle. He stood up and looked down at his hands and legs with a certain pleasurable satisfaction.

'Hum!' he said. 'Not bad!' He flexed his arms. 'Not bad at all.' He turned to Polly.

'You haven't got a mirror by any chance?'

Polly looked at him in amazement. The one thing the old Doctor never had any time for was mirrors. The only mirror on the TARDIS was, in fact, a small, battered metal one in her back pocket. She drew it out and handed it over.

The man took the mirror and held it up. He examined his face. 'Yes,' he said. 'Pretty fair, all told!' He nodded and smiled pleasantly. 'I think I'm going to rather like it.'

'You didn't answer her question,' said Ben, plucking up courage and moving forward, his fists bunched. 'Who the heck are you? And what are you doing here?'

The stranger looked at him in slight surprise. 'You ask me that, Ben? Don't you recognise me?'

The Doctor's two companions shook their heads.

'I thought it was quite obvious,' Again, he smiled his gently mocking smile and winked at them with his blue-green eyes. 'Allow me to introduce myself then. I am the new new Doctor!' Doctor!'