The Doctor looked round desperately. 'We must find a way out of here!'
'Don't be afraid, Doctor. The Xeraphin is calling us.' Nyssa spoke with the icy calm of total certainty. She approached the sarcophagus.
'No, Nyssa, you'll be absorbed!' the Doctor yelled.
She was breathing heavily. 'The Xeraphin is very close.'
'Nyssa! No!'
Her eyes shone with insane joy. 'The Xeraphin contains the wisdom of the universe.' She uttered like a prophetess.
'Nyssa! Stop!'
'Without the knowledge of the Xeraphin you cannot escape from the Sanctum.' She moved closer to the casket.
'Nyssa, the knowledge will consume you!'
'The sacrifice is required; for your survival, Doctor, and the future of the Xeraphin race.'
Nyssa knelt before the sarcophagus.
An unseen hand restrained Tegan and the Doctor as they struggled to hold her back.
Nyssa offered herself to the Xeraphin.
'Stop!' The Professor stepped forward. 'I shall talk to the Xeraphin.'
'No Professor!' warned the Doctor.
But Professor Hayter was adamant. In the space of a few hours his whole life's work had been destroyed, and all that he believed in turned to nonsense. Now he was impatient to discard his own myopic view of the cosmos, and absorb the infinite knowledge of the alien race in the casket. 'I am a scientist,' he declared. 'The chance of inheriting the wisdom of the universe is an opportunity I cannot ignore.'
'It will destroy you. You don't know what you're doing.'
'Precisely, Doctor. But soon I shall know everything!'
'The Xeraphin welcomes you, Professor.' Nyssa turned from the steps of the sarcophagus.
Professor Hayter moved reverently forward, sarik to his knees at the edge of the casket, and waited for the moment of apotheosis.
For a few seconds there was calm in the Sanctum. Then came the gusting of a great wind. The Professor trembled as if gripped by some profound emotion. He sobbed. He convulsed. He groaned. He began to writhe in alternate paroxysms of agony and ecstasy. His whole body palpitated. He gave a cry of utter perturbation.
He was dead.
The Doctor first checked that Nyssa was all right. Apart from her distress at the violent demise of Professor Hayter, she seemed her normal self. As the Professor reached out to the mind of the Xeraphin, her own link with the intelligence had been broken.
They all stood round Hayter's body, subdued and depressed. The Professor's fatal contact with the Xeraphin had done nothing to help them escape from the Sanctum.
'If only we could find the door,' said Tegan. Together with the Doctor she walked around the circular wall examining every stone.
Nyssa never took her eyes off the lifeless Professor. 'Look!' she suddenly cried.
Tegan and the Doctor stared at the dead man. The Professor's body seethed as if consumed by a million invisible locusts.
'The whole molecular structure is breaking apart,' exclaimed the Doctor.
Soon, all that had been Hayter, his clothes, and his shoes were reduced to a shimmering cloud of minute
particles which rose up and floated over the sarcophagus. A beam of light shone upward from the casket irradiating the hovering nimbus and drawing it out into a thin plume.
A spectral image began to form in the cloud like a photographic impression.
'I think the Xeraphin is trying to materialise,' whispered the Doctor.
Unearthly features started to reveal themselves, matching the detail of the compressed figures the Professor had discovered, but now projected lifesize.
A transfigured Xeraphin stood before them. The apparition spoke.
'I am Anithon of the race of the Xeraphin.'
They felt dwarfed by the presence of such an unworldly creature.
'I come in this shape as ambassador of our people.' Anithon spoke again.
'What are the Xeraphin doing on Earth?' the Doctor addressed the ghostly envoy.
'Our homeland was laid waste by barbarians, so we travelled to this deserted planet to build a new home for our people.'
'That explains the spaceship we saw,' thought Tegan.
'But the sickness followed us,' sighed Anithon.
'Radiation poisoning,' said the Doctor. And Nyssa remembered the sickening vision of death and disease that came to her as she stepped off Concorde.
The Xeraphin continued: 'Using our psychic power we melded into a unity.'
'You achieved the absorption of a whole race into a single bioplasmic body?'
'Yes, Doctor. In that shape we planned to rest until the contamination was passed. Then we could regenerate.'
'What went wrong?'
The face of Anithon darkened with despair. 'At the moment of regeneration the Time Lord came, seeking our power.'
'The Master!' The Doctor had suspected as much.
'Those who were first reborn were destroyed.'
The Doctor looked down for a moment at the victims of the Master's vile weapon.
'We were forced to retreat to our resting place.'
There was still one thing that puzzled the Doctor. He turned again to Anithon. 'How did the Master gain so much control of your psychic power?'
'Through the projection of his mind he communicated with our baseness.'
'But surely there is more good than evil in the Xeraphin.'
Anithon groaned. A shadow passed across his face. 'The schismatic effect of the Time Lord's intervention ... We are infinitely divided!' He gave a cry of pain. 'Listen carefully.' He spoke quickly, with the desperation of a dying man's confession. 'Together we can secure the safety of yourself and your friends and the regeneration of our race.'
'We'll have to deal with the Master first.'
'That is possible. I will explain ...'An agonising groan issued from the creature. A dark cancer was swelling within him. From Anithon errupted a second Xeraphin.
'I am Zarak, of the race of the Xeraphin.'
The Master knew that time was running out. If the Doctor could communicate with the white Xeraphin all his plans would come to nothing; he would never
control the Xeraphin energy, and he would be marooned for ever in the frozen wilderness. He frantically inserted the remaining components into the cable around the rotunda.
'My brother has misled you.' A glowering Zarak addressed the Doctor.
'We need no help. The Xeraphin has a new destiny.'
'No, Zarak,' Anithon cried desperately. 'The ambition of the Master will destroy our race.'
'For the new to be born, the old must die,' chimed Zarak mechanically.
'No Zarak!'
'We are the new power. The force that binds and shapes.'
The Doctor's blood ran cold. How completely the Master had subverted the selfish, acquisitive members of the Xeraphin race to his purpose!
Zarak even sounded like the Master.
The braggart voice continued. 'We shall be feared and adored. Nations will prostrate themselves before us. We shall be Divinity.'
'Zarak, that's just a dream.' The Doctor appealed to common sense.
'The Master will use your power for his own evil purposes. The Xeraphin race will never be able to regenerate.'
Anithon, encouraged by the Doctor, turned to his other half. 'Zarak,' he appealed. 'Do you not yearn for shape and touch and feeling!' He spoke with the frustrated longing of centuries. 'My brother, our true destiny is the becoming of ourselves.'
Zarak scowled. But he was suddenly less sure of himself.
Anithon pressed home the attack. 'All our power must be combined to work with the Doctor against the rebel Time Lord.'
Nyssa turned and whispered to the Doctor. 'I think we're winning.'
'Winning what, for heaven's sake?' Tegan had no idea what was going on.
In a hushed voice the Doctor explained the fateful debate between the good and the evil Xeraphin, represented by Anithon and Zarak.
'Whatever side wins the argument will control the combined power.'
Zarak was losing ground. 'You talk me out of my purpose, brother Anithon,' he snarled. 'But other counsels will prevail.'
. 'It is forbidden!' shouted Anithon.
'In the new order nothing is forbidden,' cried a defiant Zarak.
'No!' Anithon was aghast at such heresy.
Zarak began to call in an impassioned voice. 'Come forth, Kalistoran!
Come forth, Alkarim! Come forth, Vaan!'
The chamber grew dark.
'What's happening now?' whispered Tegan.
'Zarak is summoning more evil Xeraphin,' cried the Doctor.
'Come to me, Zarindas! Come to me, Mordaal!' Zarak continued the terrible muster.
'Help me, Doctor!' begged Anithon.
The Doctor had never felt more impotent. 'How can we help you!'
'With our minds!' shouted Nyssa. 'We must will the dark Xeraphin not to appear.'
They instinctively joined hands and concentrated on holding back the rising tide of evil.
The Master knew that the moment of supreme crisis had come. He completed his adjustments to the loop and rushed to his TARDIS.
Sweat poured from the faces of the Doctor, Tegan and Nyssa.
'I can't keep this up much longer,' moaned Tegan.
'You must,' gasped the Doctor.
Zarak quivered as the shadowy figures of unborn Xeraphin tried to thrust themselves from him. But the will of the Doctor and Nyssa and Tegan restrained his evil confreres.
'I think we've done it!' cried Nyssa.
'Zarak!' It was Anithon who spoke. 'Embrace again the ancient truth of the Xeraphin.'
But Zarak gave a sudden bellow of triumph. 'Too late my brother! The Master is ready for us.'
There was a grinding sound and the entire sarcophagus dematerialised.
For a moment the wraith-like shapes of Anithon and Zarak hung in the air, then, no longer supported, drifted to the ground in a flurry of dust.
The Master has perfected the induction loop,' said the Doctor in a shocked voice.
'But what's happened to the Xeraphin?' asked Tegan.
'Transferred to the centre of the Master's TARDIS.' Nyssa was as appalled as the Doctor.
Tegan still did not understand. The Doctor turned to explain. She had never seen that ashen look on his face before. He was abject with despair.
'It means that the Master has finally defeated me,' said the Doctor.
It was particularly galling for two pilots to be in a flying machine and totally unable to effect a landing.
'We must be in a perpetual holding pattern.' Andrew Bilton was looking at the TARDIS screen and its unchanging view of the Citadel some two thousand feet below.
The Captain had been scrutinising every switch and lever on the console. Nothing related to any kind of flying control that he had ever encountered. But he had no intention of staying indefinitely in this hovering prison. If they didn't help themselves, it was unlikely anyone else would. 'I'm going to have a go at flying this thing,' he announced.
'Are you sure?' A couple of lines of an old song ran through Andrew's mind; something about scraping strawberry jam from the tarmac ...
'What other choice have we got?' the Captain demanded.
He chose a small lever at the side of the console. At least it looked like a throttle. Perhaps, if he could induce some slight lateral movement, he would get enough confidence to try a vertical manoeuvre. He eased the slider forward. For a moment nothing happened. Then, to the accompaniment of a most disturbing whine, the TARDIS lurched violently to
one side.
Bilton and Stapley were thrown across the control room. As the Captain struggled to reach the console, the whole room tilted in the opposite direction. Stapley caught hold of the central panel as he shot past. A steady and sickening roll now developed as the TARDIS see-sawed from one side to the other. Captain Stapley hauled himself up from the floor and returned the lever to its original setting.
Slowly the TARDIS settled on an even keel.
'Not a good idea,' observed Captain Stapley, who had not experienced such a rough ride since a mechanical descent by a young First Officer on the simulator at Filton. 'I don't think we'll risk touching the controls.'
Bilton couldn't agree more.
'If there was a radio ...' The Captain was still determined to escape. 'We might be able to send a Mayday signal.'
'Who's going to answer it?' His copilot was less optimistic.
'Perhaps the Doctor has a remote navigational ...' He got no further.
'What's the matter, Skipper?'
Captain Stapley was staring in utter disbelief over Andrew Bilton's shoulder, at the entrance to the inner TARDIS. 'How did you get in here?'