Norris caught up with him ahead of the others. 'Doctor,' he said, 'I don't think I follow everything you've said.'

The Doctor smiled. 'I don't think any of us do,' he said as he held the door and waved them through into the corridor outside.

'But,' Norris went on, 'how does Vanessa Prior fit into all this?'

'Ah.' The Doctor stuck his hands in his pockets and looked down at the floor as he walked. 'I really don't know,' he confessed. 'You call her Nessa.

Nessa; Nyssa; Nephthys. You can be sure she fits in somewhere.' From the distance came the melodic chime of the TARDIS landing. 'We're here,'

the Doctor said, increasing his pace along the corridor. 'Perhaps her father can enlighten us as to Miss Prior's role in all this.'

When they reached the console room, the Doctor immediately opened the scanner. It showed the bas.e.m.e.nt tomb room of Kenilworth House. The sarcophagus containing Nyssa's body was in the foreground, the staircase behind.

'It's funny,' said Tegan, 'just an hour ago I was desperate for Nyssa to wake up. And now I almost hope she never does.'

The Doctor clapped her on the shoulder. 'Brave heart, Tegan,' he said.

'We'll think of something.' He closed the scanner again and reached for the door lever. 'If only we knew where the local power was being channelled from.'

'Local power?' Atkins asked. 'Couldn't it just be sent from Egypt?'

'Oh indeed it could. And undoubtedly is.' The doors swung heavily open.

'But there has to be a reception point. Even the mummies have a tiny pyramid on each of their lower backs to collect and focus the power they need.' The Doctor stuck his hat on his head and made for the door.

'Pyramid power,' Norris said, his eyes wide. 'So that's what he was doing.'

The Doctor stopped in mid-stride. 'Is there something you feel you want to share with us?' he asked politely, leaning forward and pushing his hat back on his head. Norris looked at him, his face blank. 'I was the architect for the rebuilding of this house,' he said.

'We know,' Tegan reminded him.

'I drew up the plans and supervised the work. But the plans were pretty much dictated by the owner. They reflected what Prior wanted, I just drew up the design, however bizarre.'

Tegan frowned. 'Bizarre?'

Norris nodded. 'I thought so then. Now I'm not so sure. The whole of the top section of this house - you must have noticed the slope of the upper walls, the heightened elevation of the roof?'

The Doctor said nothing. Tegan and Atkins looked from Norris to each other, and back again.

'I thought I was drunk,' Tegan murmured.

'Doctor,' Norris said, 'the whole of the upper part of this house, the internal structure, is a perfect pyramid.'

The Doctor walked slowly back to the console. He rested his hand on the door lever for a moment, staring down at the control. Then he looked up. 'I think I'd better make a couple of extra stops before I speak to Mister Prior again,' he said.

'Where are we off to now?'

The Doctor shook his head. 'Not we, Tegan. Just me. I'd like you, Atkins and Norris to find Prior. He probably doesn't realize we're on to him. Try to find out all you can about what's happening here.'

'And what will you be doing?' Atkins asked.

'Don't worry about me. I'll be back here before the fun starts.'

'You think this will be fun?' Tegan asked.

'Oh yes,' the Doctor said as he ushered them out of the TARDIS and into the bas.e.m.e.nt. 'I'm just not sure who for, that's all.'

Prior was in the drawing room. He was sitting alone by the empty grate, a facsimile of the notes from one of Carter's expeditions open on the coffee table beside him. He was leaning forward, chin resting on the sphinx handle of his walking stick. He was staring into the fireplace, as if transfixed by the dancing yellow of the fire that was not there. Perhaps he was day-dreaming, or perhaps he was watching the flames raging through his house as the fire took hold.

Tegan, Atkins and Norris stood just inside the door, watching him. He seemed unaware of their presence, even when Atkins coughed quietly and asked if they might join him. As they exchanged worried looks and sidled into the room, Prior turned slightly, his watery eyes staring past them.

Then his eyes seemed to focus, and he coughed suddenly and shook his head. 'I'm sorry,' he said quietly as he looked from Norris to Tegan. 'Really I am.'

'Sorry?' Norris stood directly in front of Prior and bent forward so that he was looking directly into Prior's face. 'What do you mean, Aubrey? What's happening? What's going on here?'

Prior did not react. The answer, instead, came from the other side of the room: 'That, Mister Norris, I think we shall all discover before too long.' Sadan Ra.s.sul stepped forward. He had been standing by the window, looking out into the night. Now he faced them across the drawing room, a semi-automatic pistol in his hand. 'You are back from Cornwall rather earlier than I had antic.i.p.ated,' he said as they backed away from the gun. 'No doubt the Doctor gave you a lift. Where is he?' He addressed the question to Tegan.

'I don't know. And I wouldn't tell you if I did.'

Ra.s.sul raised an eyebrow. 'In that case, I won't bother to ask you again.

But your tacit confirmation that he brought you here is sufficient for the present.' He laughed. 'The present present. What a strange term to those of us who exist outside Time,' he said. 'Though I confess the Doctor's particular relationship with Time does give him several advantages. For example, I had to drive back from Cornwall like the very devil.' His round, hairless face cracked into a broken smile. 'But perhaps that is my prerogative.'

Atkins pushed his way in front of Tegan and Norris. 'May I ask what you intend, sir?'

'Indeed you may. Though I am sorry to have to decline to answer. For the moment.' He nodded to Prior, who stood and walked stiffly towards the door. 'In the meantime, however, I would invite you to join me in the bas.e.m.e.nt for what will be the culmination of my long life's work. And of Mister Prior's rather shorter existence.' He waved the pistol to encourage them on their way. 'I would suggest that you all accept my kind invitation without too much fuss.'

n.o.body moved. Prior stood stiffly at the door, his eyes again glazed over.

Tegan, Norris and Atkins held their ground. Ra.s.sul smiled, his face cracked across with satisfaction as from behind him a loud swell of discordant music rose from the organ and echoed round the room.

'I have had so long,' Ra.s.sul said quietly as the organ music faded, 'so very long to form an appreciation of the motivations and eccentricities of human nature.'

'Oh yes?' said Tegan. 'And what's it taught you?'

'That a short sharp shock, to coin a rather modern phrase, is an especially effective incentive. Now, you are all expendable to a greater or lesser degree, and I do not intend you to disobey me again.'

He raised the pistol, and sighted along it. The report was like a fist slammed into an open palm. It echoed and ricocheted round the room like the organ chord before it. Norris stood for a second, open mouthed in amazement. Then his eyes rolled upwards, as if trying to see the hole in his forehead from which the blood poured down his face. The viscous liquid dripped off his chin and splashed to the wooden floor. Norris tottered, seemed almost to slip on the sticky mess at his feet, and collapsed.

They descended to the bas.e.m.e.nt in silence. When they reached the bottom of the stairs, Tegan went over to the sarcophagus. Atkins joined her at the dais, looking down at the body of Nyssa. It was completely wrapped in the bandages, silent and still. But Tegan knew that before long her lungs would heave in a great breath of air and she would begin to waken. As Tegan watched, she was almost sure that there was a slight movement, a rise and fall in the chest. Almost.

'The Doctor, I see, has returned.' Ra.s.sul was between the dais and the door. Prior stood quietly beside him as Ra.s.sul levelled the pistol at the group by the coffin.

Tegan looked round, and saw in the corner of the room the solid shape of the TARDIS. 'Indeed I have.' The Doctor stepped out from the behind one of the heavy curtains and advanced on Ra.s.sul, who swung round slightly to cover him too with his gun.

'I've been having a bit of a poke round,' the Doctor said, undeterred. 'And I think you should stop this nonsense right now.'

Ra.s.sul gave a short laugh. 'Oh Doctor,' he said, 'ever the optimist.'

'I try my best.' The Doctor looked round at the others. 'Where's Norris?' he asked quietly.

'Mister Norris will not be joining us, I fear,' Ra.s.sul replied.

Immediately the Doctor's face darkened and his eyes narrowed. 'Ra.s.sul, I promise you I'll prevent -'

Ra.s.sul's short laugh cut him off. 'I have watched from afar your pathetic attempts to prevent the inevitable, Doctor. Nyssa told me that you would interfere.'

'Did she indeed?'

'But I had no idea that your interference would be quite so entertaining.' He motioned for the Doctor to join the others on the dais. 'So kind of you to provide one of your own companions as a receptacle. So kind of you to have the entrance to the black pyramid excavated so I could recover the relics of power. So kind of you to return now to witness the final becoming.'

The Doctor stood his ground. 'And you are?' he asked levelly.

'I am Sadan Ra.s.sul. I am the high priest of the tomb of Nephthys and guardian of the sacred spirit.' He gave a short bow, keeping his eyes on the Doctor the whole time. The gun did not falter in his firm grasp.

The Doctor nodded thoughtfully, and wandered slowly towards the dais. He paused on the way to tap his finger on the top of a specimen table, and to examine the necklaces laid out on it. A small spotlight set into the ceiling cast a brilliant glow across the polished wooden surface. 'High priest and guardian,' he said quietly. 'I imagine that you were charged with protecting and preserving the prison of Nephthys.' He looked up suddenly, blue eyes piercingly bright in the spotlight. 'Since you seem to be working to ensure that Nephthys is resurrected, I would suggest you have betrayed the trust and duty of your post. Wouldn't you agree?'

Ra.s.sul shook his head slowly. 'How little you understand, Doctor.'

'I understand this,' the Doctor said grimly, 'if Nephthys is born again, there is not a power in the universe which could stand against her. Her brother told me that all life would perish under his rule. That where he trod he left only dust and darkness. Nephthys is worse. What has happened to your loyalty to your task? What has happened to your loyalty to your fellow humans, to all forms of life?'

'You know me even less than you know what is happening here,' Ra.s.sul told him. 'My loyalty is to one person only. I betrayed her once, but now I will see that justice is done, that the wrong is righted.' The gun shook slightly in his hand as if his grip were too tight, too tense. 'One person, Doctor, is worth everything.'

The Doctor shook his head sadly. 'No, Ra.s.sul. You don't know what you're doing. One person, whoever it is, is very insignificant. When all life is at stake, what is the life of one person. Make the choice, Ra.s.sul,' he begged.

'Give up the notion that you can effect a rebirth. It just won't work.'

Ra.s.sul laughed again, his eyes gleaming. 'So you would sacrifice a single life to prevent the rebirth of Nephthys, Doctor, is that what you are saying?'

The Doctor nodded.

'Tell that to Nyssa,' Ra.s.sul said quietly. 'That is the choice you had a hundred years ago. And you chose the life of your friend.'

The Doctor looked up at the dais. Tegan caught his eyes for a second, then he looked away. 'No,' he said,' no, that's different. I didn't know what I was doing.'

'And you say I do not?' Ra.s.sul's lip curled. 'You are right about one thing, though Doctor. As I said before, you don't know. You will never understand.'

Tegan could hear the Doctor breathing deeply as he looked down at the floor, hands in pockets. Then suddenly he darted across the room to the nearest wall.

Ra.s.sul's pistol tracked his movements. Ra.s.sul's smile remained fixed, as if he were amused by the Doctor's antics.

'I understand this,' the Doctor said, and grabbed a handful of the heavy velvet curtain. He heaved, face creased up with the strain, and the curtain collapsed, bringing the ceiling rail with it as it came away from the fixings and crashed to the floor. Behind it, the painted facsimile of the wall of the tomb wobbled slightly.

The Doctor walked quickly round the other walls, pulling down the curtains as he pa.s.sed until they were all piled on the floor. The room seemed brighter without the dark curtains, and the sound echoed slightly where before it had been dulled and quiet.

'A copy of the outer tomb of Nephthys,' the Doctor said as he dusted his hands on his sweater. 'A perfect copy, I grant you. But still a copy.'

Ra.s.sul nodded. 'And a copy will never allow the psionic energy we need to be focused and controlled as the original would. Is that your conceit, Doctor?'

'That was what I thought at first,' the Doctor conceded. 'But now I know better.'

'Then enlighten us, please.'

The Doctor seemed to consider. Then, unexpectedly, he grinned. 'If you'll let Mr Atkins lend me a hand, I will.'

Ra.s.sul nodded to the group on the dais. Tegan waited by the casket while Atkins joined the Doctor by the wall.

'What do you require us to do, Doctor?' asked Atkins.

The Doctor tapped the plasterboard wall behind him. 'Help me break this down, would you?'

The sound of the shot echoed round the room for what seemed like minutes. Tegan instinctively ducked. She had seem Ra.s.sul raise the gun, sight along it, and then fire directly at the Doctor - a slow motion replay of the way he had shot Norris. But although it seemed to take forever to happen, she had no time to call a warning. The bullet ripped into the wall, punching a fist-sized hole beside the Doctor's head. Chips of plaster lodged in the Doctor's hair and peppered his clothing.

Ra.s.sul lowered the pistol. 'Just to get you started,' he said quietly. 'Since we don't have very much time.'

'Thank you.' The Doctor sounded calm, but Tegan guessed his hearts were beating a little faster.