Nothing happened.

And then the cloister bell began to ring.

Somehow he had got away again. One minute he had been on the floor, inside the doorway, and the guard behind him; then he had been underneath the guard's legs; then he had gone.

Mauvril charged out through the door, screaming abuse at the useless soldier.

The Doctor was running up the hillside.

She took aim.

'No! Mauvril! You don't '

She fired.

A chunk of hillside vaporised, but the Doctor had moved, was moving crabwise towards the big gun that guarded the settlement from possible Earth Empire interference.

Mauvril muttered an instruction into her communicator, saw the gunner draw his hand weapon and take aim at the approaching figure.

'Only my personal timeline '

Mauvril fired again, and the Doctor was rolling down the slope, away from the gun, towards her.

' is holding all this together.'

Mauvril took aim again. The blaster issued a faint beep: it was out of charge.

The Doctor scrambled to his feet. 'You can't win, Mauvril. It can't work. Your beautiful future simply isn't real. It isn't stable. It can't happen. It can't happen. ' '

Mauvril took no notice. She clamped a new power pack on, then levelled the blaster.

The Doctor dived out of the way, but she'd worked out the answer to that trick now. She followed his movements for a moment until she was satisfied that she knew what his next dodge was going to be.

Then she pulled the trigger.

Axeman watched the two stranger-women hitting the breaking stone.

He knew it was a breaking stone, a thing to make stone tools with, just as he knew that this place around it, with its vast-ness and strange colours, was nonetheless a sort of nest. The place itself was telling him, even though he couldn't hear its voice. It was telling him not be afraid, constantly telling him that.

But he didn't need to be told. It was as if he had made a journey inside himself, had travelled beyond fear, beyond wonder.

He looked at his hands. So many strange things. Sounds, lights, deaths.

But this at least was familiar.

These women could not make the stones ring. He didn't know why, but it had always been the way. Only some people could make the stones ring, could break them in the way they must be broken to make tools.

He advanced towards the toolmaker and raised the stone axe in his hands.

The older woman turned to him, screamed, 'No!'

But Axeman knew what he was doing.

He angled the axe against the light from the central column of the strange breaking stone, and then brought it down with all his strength.

The beam from the blaster became visible about halfway to the Doctor. Then it spread out, shimmered and Mauvril cursed. Where had the alien managed to find an energy shield?

But no.

The air was thickening, becoming opaque. A wheezing, groaning sound filled Mauvril's ears, confusing her.

Then the blaster cut out, and an all-too-familiar blue box materialised in the air in front of her.

Mauvril felt her heart stop for a moment. The time machine hadn't been destroyed after all. The Doctor had only been waiting for the appropriate moment to recall it.

Everything had been a sham. And now the Doctor was taking away everything she'd worked for, everything she'd lived for.

'You can't do this to me!' she yelled.

She realised that the Tractite who had been guarding the dome was standing by her side, staring at her. She looked over her shoulder, saw the gunner trotting down the slope. 'Get back to the main gun!' she yelled. 'Cover that machine!'

The soldier scurried back up towards the huge black shape of the gun.

The human-made human-made gun, thought Mauvril, with a sudden shock. Perhaps he can override it... She was already at full gallop, struggling to get another sight on the Doctor. gun, thought Mauvril, with a sudden shock. Perhaps he can override it... She was already at full gallop, struggling to get another sight on the Doctor.

She saw him, running down the slope towards his machine.

'Doctor!'

He looked up, flashed her a smile. 'Sorry, can't stop, people to see, things to '

Mauvril shot at him, but he dodged. She shot again, gaining on him all the time.

He had almost made it when she caught up with him and put the blaster against his head.

He struggled.

'Not this time, Doctor,' she said.

The door of the space-time machine opened.

'Take the tablets.'

Jo's voice was fuzzy, surrounded by a bell-like echoing. Her face seemed huge, and at the same time very far away.

Sam took the tablets in her hand. They felt tiny, and cold. She put them in her mouth, swallowed Instantly she began to feel better. Jo's face became normal, human, smiling.

'Are we there?'

Jo nodded, gestured at the scanner screen. Outside, the Doctor was running down a grassy slope, fire exploding to the left and right of him.

'Usual situation,' said Jo wryly, running for the door.

Sam ran after her.

Axeman saw the two stranger-women running towards the door.

He smelled the fire outside, the danger.

This wasn't right. They would be hurt.

He started after them, pushed them aside as they reached the door.

Outside he saw the rainy-season grass, and a jumbled creature, half human, half animal: a dream thing, a spirit.

Had he entered the world of spirits?

Mauvril saw the figure emerging from the door, saw the dark fibrous body armour, and without pausing for thought turned the blaster on it and fired.

It exploded into flames, screaming.

'No!' bawled the Doctor, struggling to get free.

'Too late,' muttered Mauvril, watching the charge light of the blaster, waiting for it to be ready for the next shot.

Sam saw Axeman's burning body fall, saw Jo with her hand against her mouth, white with shock, saw the Doctor outside, struggling in the grip of an armoured Tractite.

Have to act. Have to act now now.

She crouched down, burst out of the door at a run, zigzagging wildly. She could see more Tractites charging up the slope, one heading for a sleek black object which could only be some kind of field gun.

If they get to that, we're finished, she thought.

She started through the long grass, ignoring the Doctor's shouts, ignoring the thought of Axeman in flames and this is Axeman in flames and this is dangerous dangerous The gun getting closer, the gun gun, she was going to have to do something with the gun gun because the galloping Tractite was almost there, almost on top of her because the galloping Tractite was almost there, almost on top of her She dived on to a curved surface, made of a white substance curiously like polystyrene foam, saw a wheel and a large green button in front of her.

Wheel for steering. Button for It was obvious enough. She rolled the wheel, saw the barrel of the gun pan towards the galloping Tractite.

It didn't stop.

Sam put her thumb over the button, and was going to shout a warning, a threat, the simple word 'Halt' but there was no no time time to shout, to shout, no time no time to give the alien fair warning, she just had to to give the alien fair warning, she just had to Fire The Tractite exploded.

A leg clattered down on the metal shield between Sam and the barrel of the gun. A solitary leg. There wasn't even any blood, just a seared lump of meat with a piece of charred bone sticking out.

The smell of burnt flesh and the humans are coming, they're coming to kill us all She heard the Doctor's voice. 'Sam! Try not to use '

Sam couldn't take her eyes off the leg. The hairs were standing on end, the muscles were still twitching.

A Tractite spoke. 'This is Commander Mauvril. Whoever you are behind that gun, I've got your spy here. If you value his life, you'll get out from behind the gun now.'

'Don't take any notice!' The Doctor. 'Mauvril, I can take your people to Tractis. In any time you like. But you can't alter the whole universe just to get revenge on '

Sam could hear the footsteps approaching. She had to do something now.

But all she could do was stare at the dead meat she had just killed.

'I can't kill anyone.'

It was her own voice, she realised after a moment.

'I won't kill anyone.'

That was better. At least it sounded as if she was making a decision, instead of I have just killed someone.

The Tractite spoke again. 'Good. Then come out from behind the gun.'

She could see two more Tractites approaching through the grass.

A hand touched her shoulder. She jumped, almost fired the gun by mistake.

Then saw that it was Jo.

'You might not want to kill anyone,' said Jo quietly, 'but I want to go home.'

She aimed the gun at the advancing Tractites, and pressed the firing button.

The ground exploded. The Tractites jumped back. Pieces of steaming soil spattered down around them.

Gradually, there was silence.

'Right!' bawled Jo, the shout almost making Sam jump out of her skin. 'Everyone into the TARDIS. Now. And leave your weapons outside.'

The silence continued.

Sam saw that Mauvril was talking into a communicator. The Doctor was underneath her, one huge hoof pinning him to the ground.

'Jo ' she began.

Jo turned her head, and at that moment the metal shield of the gun blazed with light.

Someone had fired at them with a hand weapon.

Sam saw Jo's hand hit the firing button, saw the leg of the Tractite she'd killed vanish into a ball of fire.

In front of them, the Tractite dome crumpled, like a building being demolished. Flames shot out of the falling wreckage, and pieces of debris began to tumble through the sky with all the crazy slow motion of a large explosion. Then Jo was turning the gun, and a searing column of fire was moving along the river valley, destroying everything it touched.