The Doctor raced back down the streets of Shan Shen, barely noticing the residents and shoppers who had to dart, dodge or throw themselves out of his way as he hurtled past them on his mad dash back to alley where he'd left the Tardis. His mind was a blur, his hearts pounding, as he careened around the last corner and saw the familiar blue of his home.

Rose his mind chanted, giddy with relief, joy, guilt and a hundred other emotions. Rose. His Rose. His precious love. He'd seen Rose. Her letter was in his hand, rumpled and creased from the desperate clutch of his fingers, but he had it – proof that once again she'd pulled off the impossible.

Proof of her love.

And an olive branch offering absolution.

A chance for him to change his past and chose anew. A chance to once again be worthy of the name he'd chosen all those years ago. Doctor.

He'd set out to be an explorer, a healer. Someone who helped. Someone who healed.

Not to be the monster all the other monsters were afraid of.

Not the man he saw himself becoming. The man he feared River wanted him to be.

Gheheris was right. This was a once in a lifetimes opportunity. The rarest of gifts, and the most precious because of what it meant. A life with the woman he loves.

If he'd thought, though, that making the decision was the hard part and that things would be easier from there, he was soon proved wrong. No, choosing had just been the start, the prelude, the warm up act. The hard work was just beginning – because the question now was how was he to make it happen.

Rose's letter had left him bread crumbs to follow rather than a roadmap or a guide book on how to change your personal timeline. And he could understand why. He was the one who kept sending her away, who avoided the difficult conversations, who dodged and dived and weaved. Three times she'd come back for him, prepared to leave friends, family, even her life behind, and thrice he had sent her away. It was his turn to make a leap of faith. His turn to prove himself to her – and that started here and now with him working out a credible plan; but therein lay the problem. He simply wasn't the planning sort. He was a wing it with Sellotape and crayons type, the sort of person who thought best on his feet when facing unimaginable odds.

Plans, in his experience, were finickity things that often went wrong and when they weren't going wrong they still weren't going right either. He'd had a plan when he stole The Moment to end the Time War. He'd had a plan facing the Daleks on Satellite Five, he'd had a plan when facing the Cybermen in Canary Wharf. He'd had a plan at Demon's Run. All of them unmitigated failures that had either resulted in his death, the death – or otherwise loss – of his friends and loved ones, and yet more guilt for him to live with.

So, no. He didn't like plans. Plans were untrustworthy thing that lulled you into a false sense of security. If you had a plan then you stopped thinking, stopped looking. Plans, in his experience, made you blind. What he really needed was the opposite of a plan – a not-plan. Something like a plan but not a plan because plans were rubbish.

For a moment guilt flickered through him, raw and acidic, as he thought of Amy and the friendship he might well loose. The future he was willingly unravelling with every decision he was now making. Every step closer to Rose meant a possible step away from the ginger Scottish girl who'd made him fishfingers and custard, and who's friendship meant so much to him.

He knew what the redhead would say. That he wasn't to touch one moment of their time together. That she didn't blame him for his enemies stealing her baby to turn her into the ultimate weapon, all with the aim of killing him. River would doubtless say something similar. And yet if he wasn't to blame who was? River had hit the nail on the head - he'd made all these people so afraid, he'd done this. Him. The him who'd lost not just his planet, but the love of his lives. He hadn't been this bad before had he? But in the centuries since Rose was lost to him for good, something fundamental had changed within him. He'd become colder, crueller, quicker to anger and less likely to forgive.

So yes, it was his fault. Totally and completely. Well… maybe not completely. Others had had a hand in it as well, but the majority of the blame? - yes, that sat with him, and he was going to change it.

But first he had to work out where in Rose's timeline he could take her so he could get the process started.

The not-plan his clever brain had cobbled together from Rose's letter was simple. At least in theory, anyway.

Find an earlier Rose, teach her the knowledge she'd need to build the dimension cannon from the schematics her future-self had included in the letter, so that she could return to him quicker than in the prime Timeline and they can bond before he meets River Song in the Library. That would disrupt the timeline he knows and prevent him from becoming trapped in the paradox. Rose was spot on; the only way to avoid the inevitability of marriage to River was to already be married and bonded before they meet. It's a neat little twist that avoids one knot completely; and meant there would be no threat of reapers from a wound in the timeline.

They would have to be careful when picking a time for Rose to come back though. It didn't bear thinking about what would happen to his precious girl should she be with him during the shitstorm of the Master and the Year that Never Was. It made his hearts shudder just to think of it.

What he really wanted was to stop Rose from falling in the first place. He'd often fantasised about going back and catching her with the Tardis in those first long, long lonely years after he lost her. It had been his secret daydream and darkest wish; and there had been several occasions where he'd come perilously close to doing just that. Sexy had stopped him each time, though, distracting him with a new adventure whenever he felt his resolve weakening.

There was also the issue that without Rose in the parallel world, would they have been able to invent the dimension cannon to get back to tell him that the planets were disappearing. It was a conundrum.

No, little as he liked it, Rose needed to fall that day at Canary Wharf, and not just because of the multiverse either. Agonising as it had been, past him needed to know what it was like to lose her – only that way would they stand a snowball's chance in hell of him getting out of his own way and bonding with her in time to prevent the paradox from starting.

How to do it though, that's the problem. He needed time. Even with Sexy helping, the probability of him being able to get Rose, train her, and get her back to Sandshoes before he noticed is slim. He'd feel her absence for one, especially if he tried it after the impossible planet when he'd finally stopped fighting the nascent bond between them. Too early, such as when was big ears and leather, would be no good either. It had to be after she merged with the Tardis and her brain started changing or she wouldn't be able to cope with the knowledge he needed to give her.

Think! He growled, hitting his forehead with the heel of his palm in frustration. Think! Smack. Think!

A ping jarred him out of his whirring thoughts, and he stared grumpily at the Tardis console. Then he spotted it, the monitor had turned on to show a lady in a ridiculously tall powdered wig and large hooped skirts.

Oh, he breathed. "Oh, you glorious, sexy thing you," he cried, springing forward to press a triumphant kiss against the time rota. "You brilliant, marvellous, wonder!"

Oh course. The spaceship with windows to France. Five hours. Five glorious hours in which to steal Rose, teach her and get her back again. It was spot on. More than enough time, even with his occasionally shoddy driving to do what needed to be done. It was perfect. Too perfect: He'd be willing to bet Sexy and Rose might have had something to do with the delay in his return. A built in save option should he need it in the future.

Well, he needed it now.

Geronimo!

Happy Christmas everyone. Next chapter will be in the near year :)