In the doorway stood Professor Hayter. Without saying a word, the Professor moved slowly towards them.
The Doctor sat on the floor of the empty Sanctum. He was profoundly depressed. He took no interest in the
efforts of Tegan and Nyssa to find where the stones had been loosened.
'If the Master's installed the Xeraphin in his TARDIS, there's no limit to his powers,' he said dejectedly. He realised that they had been fighting not only the Master, but half the Xeraphin race - possibly the most brilliant minds in the universe. Kalid had been a disguise, not only for his old adversary, but a focus for the minds of the evil Xeraphin.
'There must be some way to stop the Master.' Tegan had more fight in her.
The Doctor suddenly felt ashamed that he had been willing to give up so easily. He looked round the Sanctum, but with the Xeraphin gone, there was no way of releasing the doors and finding the way back through the cunning labyrinth that had delivered Tegan and Nyssa to the inner chamber.
He got to his feet and walked over to the collection of rocks from which Nyssa had launched her bombardment of the nucleus. They were indeed amazingly heavy - doubtless souvenirs from the home planet.
With a rock apiece they all three battered the wall of the Sanctum. But for all their weight, the strange mineral lumps disintegrated on contact with the stone of the chamber. They would need help from outside. But the Doctor could think of no way of making contact. He fought back another wave of despair.
'Listen!' The girls' sharp ears had picked up a familiar sound.
In the space left by the sarcophagus they could see the nascent shape of the TARDIS. The Doctor was flabbergasted. Only the Master would have been able
to navigate his time machine. But with the Xeraphin on board his own vehicle, he should have no further interest in the Sanctum or any use for the Doctor's TARDIS.
They all hid behind the police box as the door opened. The Doctor crept to the corner and peered round. The sight of Captain Stapley and Andrew Bilton standing in the entrance delighted him. He rushed forward and grasped Stapley by the hand.
'Are we glad to see you, Doctor!' said the Captain.
'Are we glad to see the TARDIS!' said Tegan.
'My dear Captain, you really are the most remarkable man.' The Doctor was beaming. 'To pilot the TARDIS, and with such precision.'
The Doctor, thought the Captain, has rather got the wrong end of the stick; but before he could explain they were all shepherded through the door of the TARDIS.
'You have control, as they say.' The Doctor waved Captain Stapley towards the console, still astounded at the Concorde pilot's uncanny knack with coordinates.
The Captain was quick to explain that, in any travelling by phone box, he and Bilton were strictly passengers.
'Then how did you pilot yourself here?' asked Nyssa.
"The Professor, of course,' answered Andrew.
'What!'
'Didn't you instruct him on how to fly the TARDIS?'
'No,' said the Doctor quietly.
Bilton looked round the console room. 'Where is the Professor? He was here a moment ago.'
There was an eery silence. Saying nothing, the Doctor began to set the coordinates. It was left to Tegan to break the news to Bilton and Stapley. She
spoke quietly and unemotionally. 'Professor Hayter is dead.'
Scobie wanted desperately to help the passengers. They stood in a long crocodile beside the rotunda, like a queue at a check-in desk. In fact, several had visas and boarding cards in their hands. He made a quick count of the uniforms amongst the crowd; nine of them. Except for Professor Hayter this must be the full complement of flight 192. If only he could keep them all together.
But the Master, the Tissue Compression Eliminator in his hand, prowled like a wolf round a flock of sheep. Scobie stayed in the shadows.
The line moved forward. First one, then another, then another of the waiting men and women walked straight into the pillar. Roger Scobie was no longer even surprised. Anything could happen in this place.
And it did. With a whirring and a clattering, the column, the passengers, the crew members and the Master all vanished.
No-one on board the Doctor's TARDIS could explain how Professor Hayter could have appeared in the control room and set the coordinates so accurately for the Sanctum.
'A telepathic projection?' hazarded the Doctor.
'Perhaps he isn't dead,' suggested Nyssa.
'The man was atomised!' Tegan had seen it with her own eyes.
'No!' Nyssa spoke again with that sudden mysterious insight. 'He was absorbed into the Xeraphin life force.'
The Doctor now knew that all was not lost. Even the Xeraphin - at least the white Xeraphin - were fighting back.
For a while after the departure of the Master, Roger Scobie was alone in the great hall. He thought, for a rather sobering minute or two, that he might be alone in the whole Citadel, perhaps the only example of Homo sapiens in the entire prehistoric world. It was a great comfort to see the Doctor's TARDIS materialise in front of him.
'Roger, you're safe!' The Captain ran towards his Flight Engineer.
'This place is getting just like Heathrow,' joked Scobie, disguising, with a quick wisecrack, the extent of his relief.
The Doctor overheard him. 'Have you seen another TARDIS?'
'Would that be a sort of Greek pillar?'
'Could well be.'
'It disappeared a few minutes ago.'
'We've lost him!' exclaimed Nyssa in dismay.
The Doctor didn't think so. 'The Master must still be in the same time zone, and probably not far away.'
'How do you know that?'
The Master's TARDIS won't be fully operational yet. He's got the nucleus inside all right, but he'll need to work on it.'
Scobie was explaining to Bilton and Stapley what had happened to Captain Urquhart and his passengers. 'Like animals into the ark. I've heard of a football team getting into a telephone kiosk, but this was ridiculous ...' He stopped. The Doctor was staring at him, a look of horror on his face.
'Come on!' Before anyone had a chance to explain relative dimension to a mystified engineer, the Doctor had disappeared back into the TARDIS.
They all trooped in after him.
The Doctor feverishly punched in new coordinates. 'Captain Stapley, the passengers are now in greater danger than ever before.' Without further explanation he turned to Nyssa. 'Take the TARDIS back to the Concorde cargo hold. Tegan, you come with me.' Halfway to the doors he turned back to Captain Stapley. 'Captain, I want you to get your plane ready for takeoff immediately.'
Captain Stapley reeled at the staggering optimism of the man. It was all very well leap-frogging about in an old police box, but Concorde was something else. Had the man no idea how the aircraft gobbled up tarmac before getting airborne? The facilities needed for startup? The damage done by that crash landing?
The Doctor smiled hopefully. 'Wing and a prayer, Captain?' His enthusiasm was contagious.
'I suppose we could cannibalise Victor Foxtrot for spare parts,'
suggested Roger Scobie.
'That mudflat could never be rougher than the runway at Kennedy,'
conceded Andrew Bilton.
And even Captain Stapley had the idea for a cunning lash-up to start the jets.
'The coordinates are all set,' shouted the Doctor to Nyssa and hurried off with Tegan.
The Tardis reappeared on its side in the hold of the Concorde. The Captain was first out, hauling himself through the door of the police box. He quickly briefed his copilot and engineer. 'Andrew, you and I will start
the cockpit checks. Roger, I want you to do a preliminary walk-round of the aircraft.'
Nyssa wandered round the stalk-like legs of the aircraft with Roger Scobie, It was an alien, mechanistic technology to the noble woman from Traken. She gazed up at the delta shape above her like a tourist at a mediaeval cathedral.
Roger pored over the undercarriage mechanism. 'The brakeline's fractured and we've lost a lot of fluid,' he pronounced.
'Is that bad?' Nyssa asked innocently.
'Bad?' The engineer grinned. 'It's a miracle! We can probably nick the spares from Victor Foxtrot.' Scobie picked up his tools and started to walk the couple of hundred yards to the other Concorde. He stopped.
'Do you see that?'
The distant aircraft shimmered like a calm sea at sunrise. Then the moment passed. They decided it was a bit of mist or a trick of the light and moved on.
The footsteps of Tegan and the Doctor echoed through the deserted Citadel. At every bend, every doorway, every dark corner, the Doctor looked round nervously. 'Keep your eyes open,' he whispered to Tegan.
'The Master could be anywhere.'
'Why did the Master take the passengers?' asked Tegan as they walked.
'Molecular disintegration,' answered the Doctor. 'That way he's got a neat little store of protoplasm with which he can do anything he wants.'
'Melt them down?' Tegan felt sick. 'We've got to stop him!' she cried.
When they reached Kalid's chamber, it was obvious the bird had flown.
The pedestal beneath the crystal had been ransacked for its components. Nor was there any sign of the modules the Master had removed from the Doctor's TARDIS. But the Doctor knew the Master could not have gone far. His TARDIS must be somewhere near the Citadel - in a new disguise perhaps.
A terrible thought came to him. 'Quickly!' he shouted to Tegan. 'We've got to get back to Captain Stapley!'
The Doctor and Tegan left the Citadel behind them and strode across the hard frozen earth. Tegan imagined how the centuries would erode that great monolithic pyramid, till, in her own day, there was no evidence it ever existed. As she scanned the primordial landscape, she tried to visualise the motorway, the airport hotels, the housing estates to which they were so anxious to return.
The Doctor's thoughts were less philosophical. He stopped as he spotted the two Concordes on the horizon. 'Just as I thought!' he cried.
'Come on!'
'What's the damage, Roger?' Captain Stapley swung round from his instrument check as Scobie poked his head into the narrow cockpit.
'Fractured brakeline.'
'Is that all?' Bilton couldn't believe their luck. 'Not a bad landing, Skipper!'
'Can you repair it?'
'With a bit of luck, and a bit of Victor Foxtrot.'
They were delighted at the sheer resilience of the aircraft. Only one problem remained. They had no way
of starting the engines.
Captain Stapley smiled rather smugly. He had an ingenious scheme for providing the vital compressed air. 'We'll take the tyres off one and four wheels of Victor Foxtrot.'
Roger chuckled. It was a damn good idea. But there was one little snag
... 'Skipper, have you any idea how we jack up a hundred tons of aircraft?'
'We dig a hole,' said Captain Stapley.
You've got to hand it to him, thought Andrew Bilton, impressed with the Captain's lateral thinking.
'With three and two wheels still in place you don't need to support her,'
cried Scobie.
The Doctor ran towards the parked aircraft, leaving Tegan far behind.
He was panting heavily as he met up with Nyssa and the crew who were about to start work on the undercarriage of Victor Foxtrot.
'Captain,' he asked Stapley, 'is your aircraft all right?'
'Apart from some damage to the hydraulics, but we'll take some bits of Victor Foxtrot.'
'Ah,' said the Doctor. 'Not a good idea.' Thank goodness he had stopped them in time.
'But, Doctor, it would work.'
'If that were Concorde.'
Now the Doctor's being ridiculous, thought Stapley.
'It is Concorde!' protested Scobie.
Logic, however, was on the Doctor's side. He pointed to the second plane. 'That aircraft was damaged. Now it's in perfect condition.'
He was absolutely right.
'We must be hallucinating again,' groaned the Captain.
'I'm afraid not,' said the Doctor. 'That's the Master's TARDIS.'
Roger Scobie gulped. This was worse than a hundred people hitching a lift in a lump of marble. 'It's a plane!' He tried hard not to sound narrow-minded, but really!
For the Doctor and his companions the situation was horribly familiar.
'The Master has operated his chameleon circuit.'
'And materialised round the other aircraft.'
The Captain was desperately trying to follow the bizarre reasoning.
'Then Victor Foxtrot ...' he stammered.
'Is inside the Master's TARDIS,' the Doctor concluded sharply. 'I wish I had time to explain dimensional transcendentalism,' he added, already half-way to Captain Stapley's genuine Concorde. 'I'm going into my own TARDIS,' he shouted. 'You all stay here.'