'If you act for Horus, you will know the secret of his power. Where is the focus for the eye of Horus?'

Ra.s.sul frowned for a moment. Then he threw his head back and let out a triumphant screech of laughter. 'The power of the Osirans devolves from the Great Sphinx in Egypt.' His face cracked into a smile.

'And the local focus point?'

The smile froze. Atkins could see the tracery of veins standing out on Ra.s.sul's bald scalp. 'Local?' He shook his head, and looked to Vanessa.

'Nephthys, where is the local focus?'

No reply.

'You draw energy from it, you must be able to tell where that energy comes from.'

Vanessa stared back. Her mouth was still curled into a half smile. But her face was empty.

It was the Doctor who answered. 'It's over, Ra.s.sul.'

'Never,' shouted Ra.s.sul. 'Nephthys can deduce the position of the local power source.'

'You're missing the point,' the Doctor all but shouted back. 'Nephthys is only half there - she can't deduce anything.'

Ra.s.sul flinched, as if he had been hit. Then he turned to Vanessa. The two Shabti figures followed his gaze. She stared blankly back at them.

'No,' Ra.s.sul said as the Shabti pushed past him. 'No!' he shouted as they approached Vanessa. 'She can answer. She knows the response. We are true servants of Horus.'

But the Shabti figures ignored him and continued their ponderous progress towards Vanessa. She stared into s.p.a.ce, waiting for them.

She was still staring as Ra.s.sul screamed at the service robots to attack the Shabti figures. She was still staring as he tried to stand between the Shabti and his G.o.ddess, to halt their advance. She was still staring as they hurled him out of their way across the room. He collapsed senseless at the base of the wall.

Then, out of an instinctive recognition that something was wrong, Nephthys started to back away from them.

The mummies beside the casket lumbered after the Shabti. The mummy behind Atkins pushed past and made its ma.s.sive way across the chamber to help its mistress. Ra.s.sul was picking himself up from the floor as the two closer mummies reached the Shabti. It seemed an extremely unequal match as the two ma.s.sive bandaged robots reached out their huge hands for the delicate wooden carved women.

The Shabti continued their progress as if nothing was happening. They shrugged off the grip of the mummies without seeming to notice the hindrance. As the mummies tried again to grab them, the figures turned in unison. The movement was almost graceful, hand and arm describing a lazy curve through the air. The two mummies collapsed to their knees, one toppled backwards, its legs still working, as flames and smoke erupted from its chest. The other staggered back to its feet as the third mummy joined it.

Vanessa had reached the wall. There was nowhere else for her to go.

Ra.s.sul was regaining his consciousness, shouting and screaming at her to run, but the Shabti were closing in too quickly. She faced them with fear but no understanding in her eyes.

The surviving mummies dragged at the Shabti, tried to hold them back. But the twin figures reached out, and took the arms of their flesh and blood sister. They drew the arms out, away from her body. The mummies continued to pull at the Shabti, and they in turn continued their grotesque tug of war with Vanessa. She screamed.

Ra.s.sul had staggered back to his feet, and had almost reached them when Vanessa's body gave way to the strain. The blood and tissue splashed across the room and caught him in the face. He coughed and fell. And cried.

Atkins felt sick and horrified, but he was unable to look away. Across the room, the mummies battered uselessly at the blood-red figures tearing at the remains of their image. Ra.s.sul skidded and slipped on the wet floor, his sobs adding to the unholy sounds.

Atkins felt the Doctor's hand on his shoulder, and allowed himself to be turned away. The door behind them was slowly swinging shut. They hurled themselves against it, pushing their way through. The Doctor pulled his fingers from the stonework just as the wall sealed itself into place with a grinding finality. Through the thickness of the stone they could hear Ra.s.sul's wails and cries.

'That's interesting,' the Doctor said.

Atkins frowned at the contrast between his light tone and what they had just witnessed. The Doctor mistook his expression and pointed to the hieroglyphics carved into the hidden door. The Nephthys cartouche, the opening mechanism, was gone. In its place was a congealed volcanic mess, as if the stonework had been melted away.

'The sands of time wash us all clean,' the Doctor said quietly. 'No one will ever find their way through that. And if they do, I fancy they won't find much left the other side.' Then he brightened. 'Still, all's well that ends well, eh?'

And with that he strode back across the room and slapped Tegan on the shoulder.

She pulled away. 'Is that it?' she asked. Her voice was vibrant with suppressed emotion.

The Doctor seemed not to notice. 'Yes, I think so. A pretty good result considering. All over -'

'Doctor!' Tegan screamed at him, her whole body tense with anger.

'- bar the shouting.' The Doctor frowned, his eyebrows knitting together as he leaned towards her. 'Yes?' he asked irritably.

Tegan turned away, arms folded.

'What is it?' The Doctor asked the group collectively. 'What's wrong with her now?'

'I think she might be worried about Nyssa,' Atkins suggested quietly.

'Nyssa? Oh yes, I nearly forgot.' The Doctor fumbled in his pocket and drew out the TARDIS key. 'Well, let's go and wake her up then.' The cries from behind the stone door had subsided into faint sobs now. The noise of the fight between Shabti and mummies had completely subsided.

The old woman who had woken in the sarcophagus followed the Doctor to the TARDIS. It was only after he had unlocked the door and ushered her in ahead of him that he seemed to realize that n.o.body else was following.

They were standing open-mouthed, watching him from the other side of the dais.

'Well, are you coming or not?' he demanded. From behind the sealed doorway came the faint sound of scratching. Fingernails scrabbling desperately on stone. Tegan and Atkins looked at each other in silence.

The Chronicler nodded slowly. So, when circ.u.mstances were varied, even by the tiniest of changes, the Doctor was still able to adapt and react. A by the tiniest of changes, the Doctor was still able to adapt and react. A point was made, and the Chronicler returned the holosphere's environment point was made, and the Chronicler returned the holosphere's environment to its original settings. Then he smiled, laid down his pen, and closed the to its original settings. Then he smiled, laid down his pen, and closed the book. book.