Chrysalis

"I get it," said Rose, walking away towards the room she'd claimed as her own. "You still killed her though. You killed her."

The Doctor's expression tightened. "She killed a lot of other people first," he said. "And we'd all have died if I hadn't messed up her plans."

"But you did." Rose let go of the door to her room, shook her head slightly and turned to face him. "You didn't need to finish her off too."

"I'm sorry."

"No you're not."

This time, the Doctor walked away.

Cheem was a resource rich forest world, and one of the first planets that the Trees had evolved on.

By the year that the Trees took their place amongst the star-faring civilisations of the universe, the Time Lords had become desperate for allies in their war. A war that had left the lightest scratch on most races, but torn many apart, ripping and shredding their time-streams until they wished for a death that they could no longer embrace.

The Time Lords looked down upon Cheem and approved of what they saw. The tripod structure of their civilisation balanced the ancient power of the aristocracy against the blocks of biotech knowledge jealously guarded by the newer space-faring classes, and between them were the ancient Trees, guardians of the past who had sunk their roots deep into the earth and slept for long centuries.

They saw the great spiralling cities, light and green; each city a single primitive tree that had been painstakingly grown and shaped and augmented through the ages till it held the strength to be inhabited by millions. They did not look closer; they did not see the dark, claustrophobic lower levels where Trees dragged their roots through mulch and fungus and struggled to find enough sunlight to survive.

The Time Lords saw the pomp and ceremony of the ruling class, the rituals and protocols that were strictly observed: wake at sun-up, keep your liana roots hidden in public, eat only with the right hand.

And then they saw the great long lives of the Trees.

"You shouldn't be here."

Jabe's face betrayed no surprise, but her tone was firm, authouritive. She would not let this intruder see her doubt or youth.

The Time Lord smiled. "Force of habit," he told her. He took a step towards her and held out a hand. She looked down at it. "I'm the Doctor," he said, as she continued to stare. "Clasp it with your own hand and give it a shake and tell me your name. It's a form of greeting on one of my favourite planets."

Jabe did as she was asked.

"There!" said the Doctor. "Now we know we're not going to try and kill one another."

"You thought I was going to kill you?"

"Ah...could you step a little to the left please. You're in my light."

"The Time Lord delegation was given strict instructions regarding the areas of City that they would have access to," she insisted.

"Well, I'm not with the delegation."

"You're not..." She broke off, eyes wide. "Then what are you doing here? And what are you doing?

"Ah, curiosity! Excellent. There's been a worrying lack of that around here." He moved away from the branch he was examining. It was open, and shining with sap and biotech. "The High Council are far too interested in your people for my liking. So I thought I'd take a look for myself. And you've some absolutely fascinating technology." He shut off the strange metal instrument that he had been working with. "But that's not why they're here. Would you like to save the world, Jabe?"

He smiled then, and she remembered the sapling stories of the old humans with their two arms and two legs tempting young trees out of the forest so they could chop their branches off.

The Doctor's ship was not biotech, but it was not the cold and hard machine-mind either. She touched the painted blue surface and felt it hum under her touch, felt its life, bright and warm.

"Come on," said the Doctor, and she followed him inside.

"She's beautiful," Jabe told him, showing no surprise as they entered the console room.

"Thank you." His hand hovered over the controls. "Now, where to, where to...?"

"I am familiar with your technology, Doctor. I know this vessel's capabilities."

"I wasn't going to show off," he protested. She raised an elegant eyebrow. "Well, only a little."

He took her back to Cheem, after a short while. After she'd seen enough of the universe to be fascinated, revolted, eager to depart her world and explore the stars alone.

And he'd shown her the war.

"But the Court has seen none of this," she told him.

"I know."

"We thought..." she paused, thinking. "We thought you needed soldiers, or our world's resources, or..." She shook her head. "We have nothing that can help your fight. What do you want from us?"

"Me? Nothing? I just came to warn you that the High Council doesn't have your best interests at heart, whatever they're offering you in exchange."

"Why have you done this, Doctor? Your people will not be pleased."

"Actually, they'll be furious." And he spoke as though he were delighted, before his expression grew serious again. "But Cheem has stayed out of this war so far. Not just because you're away from the main space ways, but you've kept yourselves to yourselves. Do this, and you'll attract attention. Do this and you'll be dragged straight into the middle of a conflict that could destroy you all."

"You haven't answered my question."

"They want your people, Jabe. As spies, as lookouts, as monitors. You're remarkably long-lived, your timelines can stretch through millennia and that's a huge advantage in a time war. You'll be resistant to temporal weapons, and you'll be able to feel changes in the timelines once you've jumped over a few yourselves. And that's what the Time Lords need. They are so few of us, you see."

"The High Council has offered us protection."

The Doctor's fist slammed into the console. "Protection! They can't even protect Gallifrey! We're losing this war, Jabe. We are losing and we do need something...some new innovation, some new strategy, something. But we do not need to drag innocent worlds in as cannon fodder. And you can stop that, Jabe. You can save the world."

"I've only been in Court for a few years, Doctor."

"I know you Trees: you're from an old family, you've been building support for your house for centuries. You've got to stop them from allying with the Time Lords. You can do it, Jabe. I know you can."

He could feel Rose staring after him, but he kept walking. Because she was right. He had killed: killed Cassandra, killed Jabe, and killed Gallifrey.

He'd saved her once. But being there to see her die, however much later it was, made it seem so very futile.

His hand brushed his forearm as he remembered her hard touch, a single moment of comfort and he had given a single tear to mark it.