Disclaimer: Recognizable characters are not my own - I just borrow them.

Pairing: River/Eleven

Summary: He'd spent more time than he cared to admit imagining this moment.

Rated: G

Notes: Thanks to Becs and Beverly for looking this over. All remaining mistakes are my own.

Building the Future

He'd spent more time than he cared to admit imagining this moment. When he was still in his tenth incarnation, it was all he could think about sometimes. The future him, so clever and so desperate, building the communicator into the core of the sonic - a last valiant attempt to save the woman who would mean so much to him. The woman he would trust with his name. His wife.

Only, he'd never saved her at all. Not in any way River would have wanted. And he never came up with the idea to build River's sonic - he remembered it. Remembered and dreaded it.

Later, once he knew - properly knew - who she was to him. Once he'd had River in his arms... he'd thought about this moment with a sort of all-encompassing terror. It was waiting for him, somewhere in their timelines. The moment he would build her a sonic screwdriver, take her to the Singing Towers, and send her off to her death.

He'd imagined this moment as a solemn act. He'd imagined feeling resigned and still a bit desperate. But he'd lied to himself, told himself that by this point, surely, after all this time, he'd be ready to let her go. After all, they never really ended. She was just cycling back to his beginning.

Only, they do end. He goes on without her. And he doesn't feel clever at all. Or resigned. All he feels is desperate.

All he wants is to save her. Somehow. Properly. Not this pathetic excuse for a Time Lord burial. He curses the paradox of the sonic - if he'd only not seen, he could have changed it. Could have done something else. Saved her. But he has to use this sonic. Has to give his younger self the solace of uploading her into the data core while he languishes under the weight of her loss.

His hands shake as he makes painstaking modifications. He perfects the red settings. Finally manages to work out the wood kink, though he's not entirely sure how. He turns his peaceful sonic screwdriver into a weapon with no remorse at all. Anything he can arm River with to fight shadows. To fight against time itself.

It's a lie, of course. All those additional settings meant to protect her, when all it will do is condemn her. The Time Lords knew - him more than most - that you can't fight time. All his blood and sweat and tears will amount to little more than hollow comfort to a version of him that doesn't even properly appreciate what he is sacrificing - what he is giving up.

To give up River. It's - unimaginable. Unbearable.

He almost burns the sonic when it's complete - her sonic. He throws it across the room and hopes it shatters against the wall. He opens the TARDIS doors over a supernova and very nearly tosses it in.

He's been so gentle and careful with every piece, every setting, every possible adjustment, cradling it in his hands as though it really were a part of River. And the second it's made, he wants to destroy it with the kind of dark, blinding rage that has accompanied some of his blackest moments.

Not one line.

He does not destroy River's sonic.

Instead, he pours over it, looking for any lingering flaws, any damage from his fit of pique. It's perfect, in his hands. It's just as he remembers it.

Utterly useless.

He spends a long time after that cradling the sonic in his hands. Staring at it and thinking and wishing - wishing harder than he has for anything else in his long lives - for there to be another way.

Except, there's not.

He's spent centuries trying to think of a way to save her. He's devoured books and tested theories and gone begging to experts. Nothing works.

The last time he saw her, River had mentioned an upcoming expedition to a library planet and asked if he'd like to come along, and he'd known that it was time. Only, now that he holds her sonic in his hands, he finds he cannot accept that. He shoves it in his bigger-on-the-inside coat pockets and - for the first time since his regeneration - begs the universe to keep him away from River Song.

It doesn't work, of course.

Whatever coordinates he enters reset to her flat on Luna, three days before the Library.

He hovers in the vortex and refuses to land. He wanders the halls and ignores the concerned hum of the TARDIS, stung at her betrayal. He spends hours or weeks or years lost in the depth of his ship, running his fingers over River's sonic and digging through the vast archives of information stored in his mind, looking for something - anything.

When he finally comes back to himself, to the TARDIS and the vortex and the Library three days away, the paint on River's sonic is worn from his hands and the tracks of his tears.

The TARDIS is beside herself, nudging mournfully at his mind and turning all doors to the console or their bedroom. The Doctor sighs heavily, brushing too long hair out of his eyes with shaking hands. "I need to get tidied up first, don't you think, Old Girl? I have to look my best, after all - I have a date."

He sets River's sonic on the sink and spends a long time under the spray of hot water, long enough that even his tears are washed away. He leaves the sonic there, crawling naked into their bed, his head buried in River's pillow. The lingering sent of her follows him into an exhausted sleep.

His hands are steady again when he wakes, much later. He refuses to keep track of time; of these long moments without River. Waiting to say goodbye for the last time.

Rule 408: Time is not the boss of you.

Stubbornly, the Doctor keeps his eyes closed, drifting through his memories of his wife and lingering on each precious moment. He wanted more time with her, even knowing that eternities would not be enough.

Eventually, he drags himself out of their bed. He shuts the door to their room with a horrible sense of finality - he'll never go there again. Not once River is gone.

But his hands are steady as he makes his way to the bath, eyes skittering away from River's sonic and his own reflection. He shaves his beard and trims his hair without meeting his own eyes. He's lost weight - he doesn't know when he last remembered to eat - but there's not much to be done about that.

He makes his way to the wardrobe, where the TARDIS has set out the tuxedo he wore the day he thought he'd solved the Library - those brief moments when her regeneration gave him hope. The suit he wore when she gave him all her extra lives and he realized he'd already stolen her last.

Well, River has always liked him in a top hat.

The Doctor keeps his eyes squeezed shut as he enters the coordinates he now knows by hearts, River's sonic burning right above his left one, inside his suit pocket.

He wants to turn around and run back into the vortex.

Rule 7: Never run when you're scared.

Taking several quick breaths, the Doctor marches purposefully to the doors and throws them open. He's at River's door in a few quick strides, his hearts racing at the hope of seeing her again, even though he knows it will be the last time.

Better make it a good one, then.

He hovers there, key in hand, wondering if he should put the TARDIS on invisible for his younger self. No - he'd parked in back, wasn't that what he'll tell River? Best to move it instead. That's not running - just - taking precautions.

River throws open the door as he's spinning back toward the TARDIS. "Hello, sweetie. Look at you - what's the occasion?"

The mere sight of her, after so long, leaves him breathless. The Doctor swallows down everything else and offers his most dazzling, distracting smile. "Oh, nothing special. Just in the neighborhood and fancied visiting the Towers of Darillium. What do you say?"

River's eyes widen momentarily in surprise before a delighted grin breaks across her face. She laughs, pleased, and the Doctor feels his hearts break and mend at the sound. "Are you serious? After all this time? It must be a special occasion. Just let me change - I know just what to wear."

The sonic is burning a hole in his heart. "I've just got to pop back to the TARDIS for a mo' - I've forgot your present."

River bites her lip, eyes lighting up, "Is it my birthday and I've forgotten?"

It's taking every fiber of his being not to just wrap her in his arms and never let go. The Doctor tugs at his coattails to keep his hands from reaching for her. "Can't a husband surprise his wife with a present just because?"

"A husband can. You can't." River regards him suspiciously for a moment. "What's the occasion?"

Rule 1: The Doctor lies.

"Maybe it's my birthday."

River narrows her eyes and then laughs, "You haven't the faintest idea when your birthday is, my love. But if you insist - let's celebrate." She catches him by his collar and kisses him, just a brief hello, before heading back into the house. "I'll meet you in the TARDIS."

The Doctor presses his fingers to his lips and has to grip the railing to stay standing. He hurries back to the TARDIS before River comes down to find him collapsed in a miserable heap on her front porch.

Now that he's here, the TARDIS obligingly lets him re-park in the back garden, and he's careful not to crush River's flowerbeds.

He takes out River's sonic one last time, fingers tracing well-worn grooves. He knows it down to every last wire and all six thousand and three different settings. He never wants to look at it again, and yet he never wants to let it go.

The Doctor's hand stills, a vague hope fluttering up from the pits in his hearts.

Maybe he can add just one more setting - just one more trick to save her. Maybe - just maybe - it'll be enough.

When he makes his way back through the doors, already hearing River cursing creatively about the TARDIS bulb, for the first time, the Doctor feels as though he is ready to face Darillium.

He tucks the sonic back into his pocket, the little piece of the chameleon circuit tucked away as emergency setting number 6,004, rough against his fingertips.

It looks just like he remembers.