A/N: Watching the season 6 midseason finale, I was struck by how convoluted River and the Doctor's timeline seemed to be and how tragic it all is. For the purpose of this story, however, the revelation at the end of the finale doesn't really come into play (mainly because I don't think it will ever really come into play with the way that they live their lives together). Enjoy.

Disclaimer: Doctor Who is the sole property of the BBC and frolicking rights remain firmly with Mr Moffat.

When I first met the doctor – a long, long time ago - he knew all about me. Think about that; impressionable young girl and suddenly this man just drops out of the sky and… he's clever and mad and wonderful and… and knows every last thing about her. Imagine what that does to a girl.

Trouble is, it's all back to front: my past is his future. We're travelling in opposite directions. Every time we meet I know him more; he knows me less. I live for the days when I see him. But I know that every time I do, he'll be one step further away. The day is coming when I'll look into that man's eyes – My Doctor – and he won't have the faintest idea who I am… and I think it's going to kill me.

-River Song, The Impossible Astronaut

Time can be rewritten! -Not those times, not one line and don't you dare! It's okay, it's okay – it's not over for you, you'll see me again: you've got all of that to come. You and me, time and space – you watch us run.

River, you know my name. You whispered my name in my ear. There's only one reason I would ever tell anyone my name; there's only one time I could.

-River Song and The Doctor, Forest of the Dead

He meets her in The Library; vast and dark and horrifying – and he loses her the day he meets her.

She meets him far away, in a place she never expected. And she loses a bit more of him with every new parting.

The next time they meet, there is another forest - this one with trees and space instead of shadows and books; a terrible light instead of blackness. He learns a bit more about who she is and it is good. It is engaging and entertaining and not at all what he was expecting (which honestly just makes him more intrigued and delighted). She knows all of him and his soul and he finds that he wants to know her equally.

He entrances her. He is charming and handsome and…wonderful, and his life is everything she has ever dreamed about; space and freedom. And he sweeps her off her feet and smiles at her as though there is a running joke between them, though she knows that this is only another of the few times she's ever seen him. But he knows her. He knows her and he plays her like a master, anticipating her every decision and her movements and she smiles and decides that next time, she'll dive off the cliff's edge and see what he does then.

With every meeting, he learns more and he discovers more of her. And it's in the middle of running from a local constabulary that he realises that she is the one that prompts him whenever they meet. She gives events and he recognises them, and he realises that this is one partnership that will meet inexorably in the middle before they begin again to part ways.

It has been a long time since that first meeting and she realises that he is hers as much as she is his and it is perfect. They have all of time and space, her and Her Doctor.

It is in the middle of their story that he finally, truly understands why and how he could have given her his greatest gift and confidence. It is in the middle of their story that his hearts begin to break a little when he realises that each time he sees her, she is a little less of the extraordinary person he knows her to be – the threads of her are beginning to unfurl. And he finally understands their tragedy and the fullest extent of the life they have each doomed the other to live.

She is older. In her darkest moments she begins to despair as she realises that he is younger (or as young as he can be, at any rate) and there will be a point when she will be the one prompting him instead of him casually naming a place and a figure from their shared time (because for neither one of them can it count as a true past). She begins to treasure every moment and every appearance, because each time, she can see that he moves a little further away and her heart breaks.

Time can be rewritten. But not their time and he would never dare. In his own linear time, he knows, he must say goodbye. But he will not let her go without doing it properly. It is a mistake he has made before, and she is too much a part of him for him to do her that dishonour. His oldest partner, his TARDIS, seems to come to this epiphany as he does, and he finds that more often than before, they meet and they both remember and it is wonderful. Again.

She is surprised and delighted when she realises that this is him. In between toppling corrupt powers and running from the monsters, there are times (so very rarely, but that he appears at all is a gift) when they meet and they are together in a way that in the darkest corner of her heart she never believed was possible.

At the end of their life, he takes her to Derilium to see the singing towers. They are beautiful; she is beautiful and he finally, finally cries and curses himself and his youth and ignorance.

At the end of her life, she meets him for the last time. And the first time.