Title: Inverse Law
Author: nancybrown
Characters/Pairings: River/Eleven (mentions Donna)
Rating: PG
Words: 550
Summary: The first day is also the last.
AN: Written for spoiler_song's Guns N' Curls Ficathon for gidget_zb's prompt:

Well, now,
if little by little you stop loving me
I shall stop loving you little by little.

If suddenly
you forget me
do not look for me,
for I shall already have forgotten you.

If You Forget Me - Neruda

It's in her eyes.

He doesn't often stop to stare into anyone's eyes, too busy with planning his next mad dash to notice, but they are paused here in the lee of a ruined temple, breathing in great gasps, and he's still holding her hand. He picked her up an hour ago, and they've been running for their lives ever since. He finally has the time to look into River's eyes for the merry mischief that pushes him, to take strength from her (he knows at his core that he's a taker, he takes from them all, but he tries to give them the universe in exchange), to find the love shining back at him as it always does.

And it's gone.

Her hand is warm in his. He squeezes, and affectionately, she squeezes back, her breath returned to her. "That was exhilarating," she says, "but next time, let's run before there are only three seconds left on the timer." The teasing is still there, but it's the teasing of one mate for another. She's got the same expression, the same tone, the same kindness that is not love, that Donna had.

He remembers losing Donna, the pain rushing back as strongly as on the first day when he walked away from her.

"What is it?" River's face is drawn in concern, tender as a friend, and he can't bear it. He pulls on his trickster mask so he doesn't have to see her.

"Just a hitch in my side. I'm getting old."

"Nonsense," River says. Noticing for the first time they are still clutching hands, she pulls back. "You get younger every time I see you."

How old is she now? Behind his false smile, he scrutinises her like an artefact from a lost civilisation. Not a single line is on her youthful face. She's got years and scars to earn, and he's watched each one vanish as they meet again and again. He's never let himself consider what else she will lose, though he knows, has always known.

"You should talk," he says, ashes in his mouth.

"Take me somewhere," she says suddenly, her mirth cutting through his looming depression like a knife through soft jam: he's resistant, but she's sharper. "We've saved the day, and you run off again, like every time."

"You do what you're good at." How many times has he left her with a kiss, knowing he'd see her again? He should have lingered with her, should have basked in her love instead of fled, should have known the day would come when she looked at him and saw a mad old man, her parents' friend and nothing more.

She takes his hand again. "Then show me what else you're good at."

And it's there, in the electric charge of fingers sliding between fingers, in the promise of another adventure dovetailed onto this one. She doesn't love him now. When next they meet, she will not love him for forever onwards, unless he breaks the backwards line they've drawn.

But today, this lonely, awful, heartsbreaking day, this is the day River Song falls in love with him. He will treasure these moments. He has that luxury.

"Hello," he says, because it's right, and when she tilts her head in confusion, he says, "Let's go."

The End

AN: As always, my three favourite words are, "I liked this."