A/N Before all the comments pour in, the punctuation errors in the speech are intentional. I hope you'll forgive me when you realise who it is.

He'd never forgive himself. She'd put her trust, her life in his hands. And what had he done?

He'd closed the door.

He now wakes up in the middle of the night, reeling from nightmares. He can't breathe some nights, others – in his panic – he can't see. Sometimes he rolls back over and tries to go back to sleep, but he's not usually successful. Those nights, and the nights he doesn't even bother – like tonight – he gets up.

He wanders the hallways, letting the TARDIS take him where she wants. He knows how she feels on the matter; sometimes every corridor leads to Rose's room.

She'd picked it out herself. When he took her hand and led her back to the ship, both of them still reeling from the events on Platform One, he'd told her to 'find her room'. With some help from the TARDIS, this had been it. Hers.

Tonight he's actually standing there by choice, waiting outside the door like he's waiting for an invitation to come in. He's never going to get one.

He's too tired to stand anymore so he sits, back against the opposite wall, looking at the closed door in front of him.

You're tormenting yourself the voice in his head says. He knows it's his understanding with the ship.

"So?" he says out loud.

Stop it

"Why?"

You did what you had to be done. One life to save millions

"Her life."

What makes her special? Better than the rest? Why is her life more important than the ones saved

"It was my choice..."

That's what hurts him the most. He made a choice and chose to leave her to die. Nineteen years old, in his care, and he'd made that choice.

I know you love her

He smiles. After all this time, she knows how to get him.

It's OK

"No, it's not," he replies. "A kid..."

Somewhere deep in the ship, something bangs. Loudly.DO NOT CALL HER A KID

He's learned not to piss his ship off so he immediately apologises. "That's not what I meant. She... I..."

The word you are looking for is young

"Exactly."

She spoke with me

"I never knew."

You don't know everything

"Apparently not."

She made her choice willingly. She wanted to be here

"I should never have invited her."

Why

"You have to ask?"

You would wish away all the good to get rid of the bad

"I'd rather nothing than this."

It'll pass

He doesn't reply. He doesn't want to give voice to the fact that he doesn't want it to pass. He never wants to forget what he did to Rose Tyler. He never wants to forget that he made a choice, closed that door. The consequences sit firmly on his shoulders and he wants it to stay that way.

He's moping – and well aware of it – but he doesn't care.

He sits by her door, almost watch, vigil, until morning. Not that night or morning really meant anything. He'd done it for her. Set up a definite night to give her a sense of normality. Morning was when the lights were raised and everything began as it had before. Like nothing had changed. The Doctor picks himself up and walks away, knowing that everything is different.

At various points in the day he thinks over what the ship had told him. She knew that he was in love. He wonders if Rose knew how much. He almost hopes that she didn't. When he left her to die with the Dalek he hopes that she didn't know that he loved her, because then she would have known that he still made a choice to leave her there. He hopes she understood his reasons and that she didn't hate him when the door pulled to. Besides, he hates himself enough for the pair of them.

He looks at the console, wondering what the day will bring.

He just can't work up the energy to care anymore.