Sam felt Jo pulling her down behind the gun shield, but all she could look at was the Doctor. The Tractite holding him was balanced on her back legs, her front legs pawing the air, her arms holding the Doctor against her body.

A wall of dust and flame hit them, and an instant later slammed Sam against the ground.

After a few seconds she realised that she was alive, unhurt, and the dust was settling. But this time there was no silence, only a ringing in Sam's ears.

She scrambled up, ran across the grass towards the Doctor. The grass had been knocked flat, and was full of small pieces of smoking wreckage. The big Tractite was lying by the TARDIS, her body still, apart from a few flickers of light from her armour.

The Doctor was kneeling beside her, his hand touching her neck.

'Oh, Mauvril,' he said sadly. 'You should have changed your mind sooner.'

CHAPTER 23.

Sam watched Jo and the Doctor arguing.

'It was an accident! They were firing at us! I was just trying to stop them '

'You were trying to kill them!'

'I didn't have any choice!'

'Yes you did. I had the situation under control '

'You were about to be killed and we were about to be killed! You think that's under control?'

'Mauvril was ordering them to stop firing! She was listening to me at last! She was talking to them when she when you ' He shook his head. 'Jo, Jo, Jo, Jo, Jo! I thought you knew better than this!'

There was a silence. Suddenly the Doctor swayed, almost fell. Sam darted forward, but Jo had already caught the Doctor's arm. Staring, Sam became aware of how terribly thin the Doctor was. His face, under the battered sun hat, was so gaunt as to be hardly recognisable. Had the Tractites been starving him?

'I wanted to go home, Doctor,' said Jo at last. 'I wanted to be certain that home was still going to be there.'

Then she walked away into the TARDIS.

After a moment, the Doctor went after her.

Sam looked around at the smoking chaos that had been the Tractite settlement, smelled the reek of burnt flesh. She began to feel sick. Had Jo really intended to cause this much destruction? Or had she just panicked and fired the gun in the wrong direction? Sam remembered the gun turning, the column of fire moving across the Tractite settlement. What had Jo said? 'I wanted to be certain that home was still going to be there'? Had she deliberately deliberately destroyed the entire settlement? destroyed the entire settlement?

Sam realised that she could never know for sure. All she was sure of was that the magic had failed this time. The Doctor hadn't intended the Tractites to die. He'd tried to prevent it, even at the risk of his own life and hers. But they'd died anyway.

The sound of hoofbeats startled Sam out of her thoughts. She looked around, saw a Tractite galloping down the hillside.

A Tractite She scrabbled around in the flattened grass by the gun for a weapon, any weapon, anything she could get hold of that could kill the alien before it could kill her.

She found a handgun, perhaps the Tractite commander's. She aimed it at the galloping creature.

'No!'

The Doctor's voice.

Sam hesitated, realised that the Tractite wasn't wearing any kind of armour, that he looked very familiar 'Sam! I'm not armed! Please, whatever has happened here, let us talk '

Cautiously, Sam lowered the gun.

Kitig addressed the Doctor, who was standing in the doorway of the TARDIS. 'I carved the messages. I caused ' He gestured at the carnage, then shook his head.

'You didn't cause anything. No one did. It was an accident.'

Sam frowned at the Doctor, then realised: he was covering up for Jo.

For her, too.

She wondered if he knew that she'd fired that first shot. That she'd killed killed She shook her head. No time to think now. Later, it would have to be later.

'I can take you anywhere,' the Doctor was saying to Kitig. 'Except '

'Except home. I know.'

There was a silence. Sam became aware that the smoke and dust had cleared, that the sun was shining again on the flattened grass. Flies were settling on Mauvril's body. Soon it would be vultures, hyenas.

'I think I will need to stay here. The messages '

'There aren't enough of them. I know.'

Sam stared at the Doctor. Surely he wasn't going to let Kitig stay here here? Here, all on his own?

'I didn't want to make you do it,' said the Doctor in a low voice.

'Doctor, you can't!' protested Sam. 'You're sentencing Kitig to '

The Tractite stepped forward towards her. 'To what I would prefer to do, Sam,' he said gently. 'I don't want to go to some other Tractis. I don't want to live in a world dominated by humans.'

'No Tractite would,' said the Doctor.

The Tractite swung his head around, away from Sam, and she saw his night eyes flicker open.

'Can you ' He broke off, perhaps afraid to continue.

Sam wasn't sure what he was asking, but the Doctor knew.

'I can't prevent the invasion of Tractis,' he said. 'That would just set up another paradox. But I'll do what I can to clear up the mess afterwards.'

Kitig lowered his head. 'Thank you.'

'No, no, thank you you,' said the Doctor. 'Thank you for saving my life. And Sam's. And Jo's.'

There was a moment's silence, then Kitig said, 'Will you help me bury them?'

The Doctor looked around the remains of the Tractite settlement, then looked at Sam.

She nodded. Knowing that she was going to have to face what she'd done, the stranger she'd killed.

'Of course we'll help,' said the Doctor.

CHAPTER 24.

The Imperial Throne was vast. The Imperial Throne was gold, it was diamond, it was spun pearl; it was viridian, opal, agate, majolica; it was carved fake ebony, it was spun Draconian galaxite, it was rainbows of stars and the plasma of nebulae imaged in spheres of perfect crystal. The canopy of the Imperial Throne was as high as the great rain-forest trees that no longer grew on Earth; the pillars that supported the Imperial Throne were as huge as those of the long-eroded Parthenon; and the air in and around the Imperial Throne was filtered and scrubbed until it was as clear as the air of mountain valleys had once been, before they had been filled with the detritus of centuries of industry and war.

In the middle of the Imperial Throne, on cushions of velvet and satin and force and air, sat the tiny, wrinkled husk of a woman.

The Empress.

Her hand still rested on the controls of the gold-and-obsidian magnaflux drive which had brought her instantaneously from Earth to Tractis: the single most powerful machine in human history, controlled by the single most powerful human ever to breathe the air of Earth.

Sam stood, refusing to kneel.

She wasn't a subject of this woman. She didn't care what everyone else was doing. The humans, the Earth Reptiles, Draconians, Ice Warriors, Zygons, GorEntelech, even the Tractites, all knelt around her, thousands of them in every kind of regalia under the almost infinite marble-and-gold ceiling.

But the Doctor had remained standing, despite the weakness of his still-emaciated body. So Sam was standing too.

She felt the Empress's eyes on her, felt the power for a moment.

At last the shrivelled woman spoke.

'It pleases us to allow the request of the Protectorate of Eta Centauri 6 to assume the status of a Duchy Royal, with the name of Tractis. It further pleases us to appoint as our personal representative to the Duchy the Earth Reptile Ambassador-General Menarc.' A pause. The eyes in the shrivelled face blinked. 'So decreed decreed, by authority of the Voice of the People of the Empire, on this day '

'You know who she reminds me of?' whispered the Doctor. Sam shrugged. 'Old friend of mine. Name of Davros. He used to make decrees as well, and it didn't do him much good either.'

'Never met him,' said Sam.

'I hope you don't.'

Sam glanced up at him, frowning. There had been a definite undertone to those words, as if Well, think about that tomorrow.

The cheering had started around them. The Empress's decree didn't sound like much, but in practice, the Doctor assured her, it amounted to independence.

In here, the Baron's Residence, the cheering was muted, but outside, Sam knew, it would be like thunder, the joyful braying of a thousand million horses.

But when Sam looked up at the Doctor's face, there were tears on his cheeks. Amazed, she put a hand on his arm.

'What's the matter?'

'Mauvril,' said the Doctor. 'Kitig. All the others. I wish '

Sam bit her lip. 'So do I.' She still hadn't told him about that first shot, about the Tractite she'd killed. Somehow she couldn't quite bring herself to do it.

She tried a smile. 'At least we could save the habilines.'

It had almost been worth it, seeing the smiles on those nearly-human faces when the Doctor had walked among them, feeding them with vaccine-filled jelly babies.

The Doctor jogged her arm and Sam realised that the Earth Reptile Ambassador-General had begun to speak, announc-ing free elections and the formation of a planet-wide council.

'Will it work?' muttered Sam as he droned on.

The Doctor shook his head. 'The Earth emigrants will form a separatist party and assassinate council members. The Empire will be falling apart by then, but it will try to restore order. Unfortunately, it will make a mess of it. Hundreds of thousands of people will be dead at the end of the war. But after that, it will get better. It will will.' A pause. 'Anyway, it's the best I could do.'

Sam looked down at the jewel-studded floor, then took a grip on the Doctor's arm and began to steer him towards the exit.

'What's the matter?' he asked. 'Where do you want to go?'

She flashed him a grin. 'Come on,' she said. 'There's a world to explore. And whatever's going going to happen, they're happy today.' to happen, they're happy today.'

The Doctor looked at her for a moment, then smiled back.

It was like a moment of sunrise.

She led him outside, beyond the marble gardens and sterile air that blew from the palace, under a blue sky and along the coloured streets of a vast and happy city, where the billion inhabitants of a small, grassy planet were celebrating their freedom and their victory.

EPILOGUE.

His arms aching, Kitig lowered the chisel and surveyed his final work.

Yes. It was good enough. The letters gleamed in the quartzite, catching the low-angled light of the early-morning sun.