That was one Brigadier accounted for. Now he had only to track down the younger Lethbridge-Stewart.

'Doctor!'

Turlough held his breath.

'Doctor? Tegan? Nyssa?'

The voice came from a nearby corridor. Turlough crept towards his quarry.

All eight mutants were once more connected to the regenerator. So, too, were the Doctor, Nyssa and Tegan.

' You You will activate the energy transfer, Brigadier,' will activate the energy transfer, Brigadier,'

instructed Mawdryn. 'It will take several seconds for the charge in the machine to build up. You will read off the countdown to the moment of exchange.'

Brigadier Lethbridge-Stewart nodded grimly. Tegan and Nyssa glanced nervously at each other.

'Do not be afraid,' said the mutant wired up beside them. 'When the moment comes we will all share in the life-force of the Doctor.'

'Our mutation will end,' said another, his eyes shining with expectation.'

'And you will no longer be contaminated.'

'And the Doctor won't be a Time Lord any more,' said Nyssa guiltily.

The Doctor, electrodes festooned round his head, stared stoically ahead.

'My brothers in exile.' Mawdryn's voice shook with emotion. 'We approach the ending!' He pointed to the master control. 'Activate, Brigadier!'

There was a low whine as the power began to surge within the regenerator.

'Twenty seconds,' announced Brigadier Lethbridge-Stewart.

'Brigadier!' shouted Turlough, running wildly down the corridor. Somehow he had missed the other man. He felt the fury of the Black Guardian possess him.

'So near the supreme moment!' The voice, thundering in his brain, seemed to vibrate the whole ship. 'The Brigadiers must not converge. Find him! Find the Brigadier at once!'

The younger Brigadier was intrigued by the strange sound coming from the narrow side-pa.s.sage. 'Brigadier!'

Someone was racing towards him down the main corridor. Turlough again! He would deal with that young man later. For the moment, there was something very strange going on in the brightly lit room at the end of the pa.s.sageway.

'Ten, nine, eight...'

He could hear a voice, curiously familiar, but difficult to place.

'Brigadier!' Turlough had almost caught up.

'Stop him!' howled the Black Guardian, 'or I shall destroy you all!'

'Seven,, six...'

'Brigadier, come back!' Turlough grabbed the arm of the man in the blazer, but was pushed roughly aside.

The Brigadier from 1977 entered the laboratory.

'Five, four...' The Brigadier from 1983 read off the final countdown.

The intruder was momentarily hypnotised by the spectacle of eight mutants, conjoined in a ganglion of tubes and wires. Then he caught sight of a young man in a frock-coat, also connected to the apparatus. 'What the devil...!'

'Three...'

The newcomer took a step forward, and, to his disgust and horror, saw Tegan and Nyssa lashed to the same devilish torture machine.

'Two...'

'Brigadier, get out of here!' yelled the young man. The Brigadier took no notice, but advanced towards the swine at the controls.

'One second...'

'What do you think you're doing!'

The operator turned.

For a moment time stood still. Brigadier stared at Brigadier, then, as their hands touched, there was a blinding flash and a tremendous explosion.

8.

All Present and Correct Turlough ran and ran and ran, as if perpetual movement would keep the vengeance of the Black Guardian from him.

He finally stopped from sheer exhaustion, feeling strangely light-headed. He took out the cube; it was cracked. Was this all part of the Blinovitch Limitation Effect? Could he even be... free?

Turlough set off, purposefully, in the direction of the TARDIS.

Tegan and Nyssa regained consciousness as the smoke was clearing in the laboratory. They opened their eyes to see the Doctor unwiring them from the regenerator.

'What happened?' murmured Tegan.

'An immense discharge of energy as the two Brigadiers came together, exactly synchronising with the moment of transfer.' The Doctor walked over to examine the body of a man in a blue blazer, lying beside the regenerator.

'Is the Brigadier dead?'

'No,' said the Doctor, in the certain knowledge that the unconscious Lethbridge-Stewart had at least another six years of life ahead of him.

'Doctor!' Nyssa had spotted the p.r.o.ne figure of another, older Brigadier, with a totally uncertain future, who lay in his singed sports jacket, on the far side of the laboratory.

The Doctor rushed across and knelt beside the old soldier, feeling anxiously for his pulse. For an agonising moment, he felt nothing. The Doctor groaned. That he should have caused the death of his oldest, most trusted ally on the planet Earth, was unendurable.

Then he felt the faint but steady beat as the Brigadier began to stir. 'It's all right, old friend.'

The Brigadier opened his eyes. 'Sorry, Headmaster,' he muttered deliriously, 'touch of vertigo. Won't happen again.' He blinked, and was suddenly wide awake. 'What the devil's been going on here?'

The Doctor grinned. This was more like the Brigadier of old. 'Quickly, Nyssa. Take the Brigadier to the TARDIS. Right into the centre and keep him there until I give the all-clear.' With a few words of encouragement to the confused Lethbridge-Stewart, he bundled them both out through the door.

The Doctor walked back to the regenerator control panel. 'Amazing the Brigadier's timing. A millisecond either way and...'

'And what?'

'At the moment of exchange, the power didn't come from me, after all.'

'From the Brigadier?'

'From the TARDIS, really. Through the energy released by the Blinovitch Limitation Effect.'

'Can Nyssa and I time-travel?'

'You're as good as new.'

The Doctor was smiling confidently, and Tegan realised that, most important of all, he was still a Time Lord, with all his powers of regeneration intact.

They looked at the eight mutants. All were lying peacefully, as if asleep, the terrible blemishes gone from their bodies, a look of sublime calm suffusing each face.

'They're all dead,' said Tegan quietly.

'They would have travelled for the rest of time,'

explained the Doctor. 'Death was all they wanted.' As he peered at Mawdryn's unravaged face, the mutant leader opened his eyes; the life had not entirely drained from him.

'It is finished, Doctor,' he whispered. He smiled a smile of utter contentment. 'Can this be... death?' His eyes closed, as his unfettered spirit soared to join his comrades, beyond the realms of time and s.p.a.ce. It was the ending.

It was an exhausting business carrying the unconscious body of the younger (and thankfully lighter) Lethbridge-Stewart to the TARDIS. Half-way, Tegan and the Doctor had to stop for a rest.

'By the way,' said Tegan, suddenly very self-conscious.

'Thank you.'

'What?'

'You were prepared to give up everything for us.'

The Doctor just smiled and stood up. 'Oh, come on!'

Hardly had they begun to move again when they both came to a sudden halt. All around them the ship was beginning to creak and groan.

'The ship is dying with the mutants,' whispered the Doctor. 'Come on!' he shouted more urgently. 'It must be on auto-destruct.'

Jubilee Day, like the day of the Coronation itself, had been wet in the morning, but the clouds had rolled back by lunchtime, and the sun was shining brightly as Doctor Runciman climbed the hill to the obelisk. He wondered what on earth was the point of this mysterious rendezvous with Lethbridge-Stewart.

'Brigadier!' he shouted, as he reached the summit.

'Brigadier!'

Doctor Runciman walked off into the surrounding trees, and subsequently failed to see the blue police box materialise on the other side of the hilltop. By the time he returned from scouting the woods, the Doctor and Tegan had placed the unconscious Lethbridge-Stewart on the gra.s.s, and had returned to the TARDIS.

'Brigadier!' shouted Doctor Runciman, running towards the rec.u.mbent maths master.

The Brigadier groaned.

'Brigadier, what happened? I came as soon as I got your message.' He helped his patient to a sitting position.

'Brigadier, are you all right?'

Brigadier Lethbridge-Stewart stared straight ahead over Doctor Runciman's shoulder. He was still very dizzy, but could see the outline of what looked like a blue police box, which gradually... disappeared.

'My word, Doctor, you've been making a few changes in here!' The Brigadier, whom Nyssa had been keeping safe at the heart of the TARDIS, walked breezily into the control room.

'We all have to move with the times.' The Doctor smiled. 'How are you feeling?'

'Haven't felt so well for...' The Brigadier laughed. 'For six years, Doctor!' At last he understood the reason for his nervous breakdown. He breathed a sigh of relief.

Tegan was laughing too; this was more like the Brigadier she had met on her last visit to Brendon.

The Doctor indicated the flashing column. 'On our way to 1983. Back to school, Brigadier.'

The Brigadier smiled politely, as if a friendly travel agent had just offered special rates for a round trip on the t.i.tanic t.i.tanic, or Benton given him first refusal (special favour for you, sir) on some old lady's Morris Minor. If there had been a tram, a train or a Green Line bus, a dodgem car or a fairy cycle going in his direction, Lethbridge-Stewart would have taken it in preference to the Doctor's police box. (And Scotsman or no, paid full fare).

The Brigadier knew the TARDIS of old and, as the column slowed and stopped, he wondered where on Earth - or anywhere in the Universe - they were this time. The Doctor and the two girls escorted him to the door.

'Bless my soul!'