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do I, Yes
"I am a constant satellite of your blazing sun
My love,
I obey your law of gravity
this is the fate you've carved on me."
.
The River Song standing across from him as time disintegrates is in love with a fairytale. He doesn't doubt that she loves him, not at all, but this River is young and she doesn't understand why he's looking at her with bitterness, with hesitation, even though it's not him but he's inside watching, the TARDIS humming in the background. He just stands there as she tells him that she'll destroy the entire world if it means saving him, but all he can think about is her and the Library, handcuffed to a metal pole as he yells – "Time can be rewritten!" and she's giving him this look, with tears in her eyes because she knows this is her end, but there's almost a sort of smile on her face as she says – "Don't you dare."
This River is a River who knows less about him, doesn't yet know of the things that he is capable of doing. She knew it all in the Library and back then he was the one that was young and he watched her die, a woman he's never met before who knew his true name.
He wonders how she knew, because he won't tell her just yet. He's not sure if he will at all but at the same time he knows he does, eventually, because she whispered it so quietly in his ear and all he could do was stare.
He still finds it amusing how Amy and Rory were not even a part of his life back then and it was Donna, magnificent Donna who was made to forget everything, and he went and killed their daughter. But no, then he saved her, and this thought makes him so incredibly sad. Because she's River and in a way he does love her.
This River Song in front of him is desperate and infatuated with the idea of him – psychopath, she still calls herself – and he doesn't think that she's hit Love just yet. She's younger than he's ever seen her before and he wishes things didn't have to go like this. He wishes that they could just stay and stop moving away from each other and just be. But it's not possible and he has a world to save.
(He always has a world to save. He's grown so used to it that even when he tells himself no, no more, he can't resist.)
He fixes his cowboy hat and the Tesselector leans forward. "Look into my eye," it says so he grins, does a little jig on the spot, and tries to convey that everything will be alright. He hopes it works – no, he's sure that it will work because even if this River is young she is still River and River has always been brilliant.
As time rewrites itself to its proper course and he's back on the beach, inside the Tesselector being killed he steps into the TARDIS and thinks that one day he will have to marry River Song properly once and for all.