Author's Note: It's been a long time coming, but this is the last episode installment. There is an epilogue, however, so one more piece to come. Thank you so much to everyone who's been following this story over the years, who have been dedicated readers and reviewers, who have favourites and commented much more than I ever thought would be imaginable with something like this. Just ... thank you. This is one of my most reviewed stories and I can't really express how that makes me feel, apart from wonderful. If you're interested in the rest of my work, 'Reckless Abandon' is on its way up on FFN now (although it is, as yet, incomplete). I'm also working on a Peter Carlisle/Rose & Ten/Rose fic which I hope to start posting soon as well. It's been a long journey, for Ten and Rose as well as us fans, and I hope you guys will keep loving them as much as me.

Part the Fourteenth – Doomsday

He still sees that image of her, being ripped away from him, in his dreams. It's another reason he doesn't sleep until he's too exhausted to even breathe and darkness takes him for a couple of hours. Even when he closes his eyes she's there, reaching out to him as she screams, being sucked away to nothingness.

Except, not nothingness. Her father – her brave, wonderful, father-who-isn't – knew that he had to come back, to save Rose. Pete did what the Doctor could not, and that knowledge is going to eat at him for years to come.

The TARDIS is quiet. The hum is there, the serene humility of his ship calming his mind, but there's nothing else. There's no presence of another person, no noises that shouldn't be, no laughing or snoring or singing. There's just nothing, like he's the one who's been left behind, trapped forever between dimensional walls that may as well serve as his prison.

It's been three months since Canary Wharf, and he doesn't even try to pretend that he hasn't been counting the seconds, minutes and hours as they drag by. He hasn't done anything. How can he go outside, alone, and carry on by himself? Without her hand to comfort him, or her smile to warm him, the world is as cold and unwelcoming as it was after the Time War.

And isn't that ever the burden he carries? That hurt was different. He was a traitor, a liar, a schemer and all in the name of the Daleks. The Daleks, who he fails to destroy time and time again, no matter how hard he tries or what he does they always return.

It's like the universe is mocking him.

Rose is... was... something else. Forbidden fruit he allowed himself to taste, just once, but of course, it's never just once is it? She's nothing of his race or his heritage, but she's everything of his hearts. He doesn't like to admit it to himself, never to her, because he's too proud and scared of what that might mean.

No, he corrects, what it does mean. Or did.

The guilt returns, he finds in the first month. The guilt of not only what he did – even if they resolved that, eventually, sort of – but of what he didn't do. Not strong enough, brave enough, quick enough, clever enough – all the words that mean nothing but labels, and he's not enough of any of them.

The thing that hurts most is that he let himself believe he could have it. That a life and love with Rose would actually be possible. It's typical, he thinks, that just as he's found a path where can be happy, if terrified, the stability gets torn away and he's left with a hole only to be filled by heartache.

She chose him. She chose him, over her own family, even after what he'd done to her – and he believed her. He wanted to believe he could keep her, tucked away in the TARDIS, as his own, someone he didn't have to give up and someone who wouldn't leave him. And he knows, now, that he can never have that. It's the universe's way of telling him he is destined to be alone, the last Time Lord. Left to pick up the debris of planets because there's no one else to do it.

He doesn't want to think of what will happen when he dies, finally, or what will become of the multiverses.

Rose's forgiveness still flicks back to his mind, in brief scenes, like re-watching a video that's been corrupted over time. She had promised him forever now long before, and he'd believed that, too. Perhaps that's why he hadn't been able to keep her memories to himself any more, why he admitted exactly what he'd done and hoped she wouldn't sob too hard on her way out of the door as she left him.

But her forgiveness, if unexpected, made him love her in a new way, in the way that promised no matter what happened between them they could sort things out.

But it's the promises that are dangerous, especially in terms of a Time Lord, and he thinks it's about time he stopped making them.

He doesn't know what he's looking for, sitting alone in the TARDIS. It's like he's waiting for an idea to strike, or a miracle to happen, or for Rose too suddenly appear in the doorway and tell him it was an awful, terrible nightmare. He's been calculating sums, reading textbooks, researching cases of all things – possible and impossible – that could lead him back to Rose.

At first, he was sure he wouldn't lose her. Two parts of him argued, spat, kicked and shouted with each other and gave him no peace in his head. She's happy, one said. She's with her family, where she should be, and she can finally have the life she deserves and the life she never could have had with him. She can fall in love freely and do as she wishes and grow old and die and be happy. You liar, says the other part of him. If you wanted all that for her you never would have picked her up in the first place. She was never a one-time visitor or a "quick trip in the TARDIS". You saw something special in her almost as soon as you met her, and you wanted that.

He hadn't, he does admit, expected to feel for her as he does. So soon after the Time War he needed someone to hold on to, to give him strength in life again, and brave, wonderful Rose did that. But then she became something she never should have, a beacon in the dark that he doesn't deserve and has never thought even existed for him.

He's still not sure, if he ever saw her again, what he would do. Beg her to come back to him, or tell her he's happy and hopes she has a good life?

He knows what he wants to do, but he has a sneaking suspicion the opposite is what will come out of his mouth.

Except, he's working on hypothesis. He isn't seeing her again, ever, and the last image he's going to have of his Rose is of her screaming for him and him being able to do nothing about it.

He wonders what she'd say to him, if she got the chance. If they saw each other again for a final time, a last goodbye. Would she tell him to keep travelling? Beg him to fight for a way through? He likes to think that while he's cooped up in here, in the TARDIS, trying to find ways through that won't split both universes in two, that she's getting on with things. That she's accepting her life and settling into it.

It's been three months, after all. He doesn't even want to imagine that she's as miserable as he, or that she's spending her days pining for him. Because he's not going back. He's exhausted all his ideas, all the equations he can think of, all the textbooks he owns. Everything says it's impossible.

The only thing he can hope for is a crack, a back door, but the chances of falling through the first were a million to one as it is, let alone a second. When the Cybermen punched their way through they left cracks between the realities – he can't afford to shatter that, after everything he and Rose fought for.

He wishes she'd listened to him. Stayed with her parents, stayed in the alternate reality when he said, when he was in control. At least then this would hurt less. But she's Rose, when has she ever listened to him? Even since the first time they were in danger, back in the strange basement in London with the Autons and Nestene Consciousness, he'd told her to run and she'd done just the opposite: saved his life.

Maybe that's what she was trying to do again, this time, by insisting that she stay with him no matter what. Maybe that's why he believed her.

The Doctor sighs loudly, dropping his head into his hands and digging his fingers deep into his chestnut hair. He's sitting cross-legged in the console room, a heavy textbook by his shoes, another by his left knee, and three more piled up by his right. He's been reading for days, but the texts are all useless.

Without words, he closes his eyes and sends out a prayer to the universe, to anyone who's listening. He can't have her back, he knows that. But he wants, so very much, just to see her again. To say goodbye. He never gets to say goodbye, his cowardice always gets the better of him, but if there's one person who's worth that courage, it's Rose. Rose, who always gave such courage to him, even when he didn't deserve it. Rose, who stood up to the enemies they faced just as proudly as he did. Rose, who showed him that living life on the outskirts isn't lonely when you have the right hand to hold.

The tears cloud his eyes before he even feels them rising.

He could ask how, or why, the universe is doing this to him, but as far as he can tell it's all par for the course. Is it so bad to want just one more look, one more touch? To say what deserves to be said, what needs to be said?

His hands fall to the cold metal grille of the floor and he swallows hollowly. He laughs bitterly, in the face of everything, because once again the Cybermen and the Daleks did what he could not, what he could never do. They managed to punch a hole through the universe, didn't they? It took them months, but they crossed over. He can't do that.

But...

He sits up abruptly, blinking like he's just woken up.

He can't cross through. But perhaps, if he can... imprint himself onto the other universe, like the Cybermen did, maybe he can... get to her. Talk to her, communicate with her in some way so she knows he's looking for her, tell her not to give up hope.

Except, he can't do that. If he sees her again it has to be for goodbye. He can't keep doing what he's doing: the world moves on, and he has no choice, he's got to move on with it.

The thought alone makes him shudder, but he knows there's nothing else he can do. So, with a heavy heart, he sets the TARDIS to lock on to a star that's close to death. He can, if he thinks about it, ride the energy; it'll carry him through the many cracks left between their two universes, the remnants of the Cybermen's damage. And maybe, finally, he might just get to say goodbye.