The Lights of Aeterna

It's a beautiful night on Aeterna II. Overhead, four moons dance in a sea of colours, some of which the Earth has never seen. The observation balcony is deserted, a dark bow in the side of an abandoned skyscraper, a monument to a civilisation lost to the ripples of time. Shadows crowd at the edges of her vision, but River Song is sitting in the curve of the Doctor's arm, together in the reflected light of one of the universe's miracles. She is thirty tonight, and literally on top of a world, and their life together is a beautiful yet fragile thing, held in their cupped hands.

'You're quiet tonight,' she says, nestling her cheek against his shoulder, his breath ghosting across the top of her head.

'Who needs talking with a view like this?' he counters, his voice light. She almost laughs, almost teases about finally finding the one thing in the universe that can shut him up for a moment, but something deep in his tone startles her; or perhaps it's the way his arm tightens incrementally, instinctively around her waist.

She hasn't travelled with him for eight years without learning to read the signs. 'Something's wrong,' she says, keeping her voice neutral. Eight years ago, she wouldn't have noticed. Five years ago, she would have had a fight with him for hiding things from her. Two years ago, after their flight from Hosking Four, she would have waited until they were back in the Tardis, back in safety, before confronting him. Today, she simply asks, here and now, pressed against the quiet rhythm of his two hearts.

Eight years ago, he would have kept quiet. Five years ago, he would have smiled that sharp smile of his, fond and slanted all at once, and said, 'Spoilers'. (Ah, how she hated that one little word.) Two years ago, he would have told her what she needed to know, after a long, protracted attempt to evade her questions, and perhaps after getting his hand forced by some aliens attempting to shanghai the Tardis.

Tonight, she feels him press a kiss into her hair, buying himself a little time. She watches the moons of Aeterna II dance across the night sky, as he holds her close, the silence between them a warm, familiar thing, soft with memories and laughter and comfort.

'I'm beginning to understand,' he says at last, his voice muffled in her curls. He's still keeping it light, but a whisper of pain – or is it apprehension? – dances along the edges, like the golden edges of candle flame.

'Understand what?' her younger self would have asked impatiently, but she waits, lets him pick his own way across the words. He'll tell her what he can. She'll look for the rest of what she needs to know later, in her own way, and he won't stop her.

The moons are flashes of light in an eternal sunset, the oceans of a world spread out at their feet, reflecting the kaleidoscope of colours above. She's never seen anything quite so beautiful, except perhaps the look in his eyes on a day when everybody lives.

'Since you were born, your parents and I have been fighting to protect you, to keep you safe,' he says, and the arm around her waist is tighter yet, pulling her into him, as if she might escape – or be taken. 'I can't…I can't tell you why, and I can't tell you how.'

She thinks of how her childhood memories don't begin until age seven; she remembers the way her dad kept a sword hanging by the front door and another under his bed –an eccentric collection, he'd said; she feels the shape of a gun in her hand, pulled from underneath her mother's pillow, sees the omnipresent mobile in her mum's fingers, a mobile which her mother never used, but caressed like a weapon, or a lover.

As far as she'd known, he'd never met her parents.

'They kept you safe for thirteen years,' he's saying, above the roaring in her ears. They were her parents, staid and puttering. They were quiet, normal people, who never seemed to have grasped modern technology. Stuck in the fiftieth century, she'd always told her friends, rolling her eyes. They'd worked hard, and lived quietly, and there'd been nothing special about them, except perhaps a bit of wanderlust that kept them moving. What had she missed? How had she missed it?

'And then I ran away,' she whispers, voice rough against his jacket.

'The echoes in your head,' he agrees, but doesn't explain. Her arms prickle – silences and shadows whispering at the edges of her dreams – but she shakes it off.

'And I found you.'

He breathes out a tiny laugh, barely vocalised, fond and a little exasperated, all at once. 'Yes, you found me, after I'd spent two years searching the universe for you. Your mother was frantic.'

She'd been twenty-two, perched atop the church tower at New New Harvard. Holding a priceless artefact in her hands, with campus police thundering up the staircase behind her and Adesina's hopper failing to show, she'd been rapidly constructing and discarding a series of impossible plans, when a man had suddenly appeared on a balcony below her. 'Jump!' he'd said, extending his arms, and she had, plummeting without a second's further thought.

A beginning.

'Why are you telling me this?' she says, her face still pressed against his shirt, which smells like him, soothing and warm and slightly minty. 'If you and my parents have kept secrets from me for so long, why now?'

'Because I've spent so many years fighting something I didn't understand, and now…'

'And now you do,' she says, after a moment, finishing his sentence, feeling something curl in the pit of her stomach. Something stirs, in a far shadow, and she shivers.

'Now I'm beginning to,' he agrees.

'What does it mean?' she asks.

The light show is fading, a short but brilliant moment, here at Aeterna II. Happens once a millennium, he'd said earlier that evening, when he'd parked the Tardis with his usual showmanship, grinning across his entire ridiculous, infuriating, lovable face. Perfect for a birthday girl, he'd said, despite her protestations that time travellers couldn't really do birthdays. Thirty, he'd said, was a big birthday – she'd made it to thirty, despite her refusal to stop wandering off, and he was the one who was going to help her celebrate.

'I don't know yet,' he says, and the honesty in his voice makes her close her eyes against a sudden blurriness. They fly through space and time together, and lying is a part of daily life. He lies easily, winningly, beautifully, wittily; he lies to protect people and to do his job; he lies because part of his very being is a lie, or at least is beyond what ordinary beings can perceive as truth. She's not vain or stupid enough to flatter herself that he never lies to her – if a lie would protect her, she knows he would lie in an instant. As would she, to protect him. And yet, it's with her that he allows himself to be most vulnerable, with her alone that a truth comes more naturally than a half-truth or a prevarication.

'What do you know?' she asks, pushing, not even sure she wants him to tell her. She always wants all the information he will give her – always pushes and pulls until she gets more – but in this instant, she has to tamp down the echo of a fear somewhere deep in her stomach. There's a cold wind across the back of her neck, and she shivers and arches into him.

He holds her close, closer than close. 'I'm eleven hundred and one,' he says as if to himself, hushed, into the dying light of the moons, 'and you're thirty. I'd hoped we'd have years and years yet, before things had to change. Years and years, human years, and all the adventures in the universe…'

He trails off, something hollow behind his usual chatter. She shivers again. 'You're talking as if you think something's going to happen to us.'

She feels the hesitation spread through his body, the tension taking over his gangly limbs. 'River,' he says at last, and the sound of her name in his mouth makes her thrill, as always. It's a caress and a promise, all at once, and she's always known that she'll get no grand declarations from him, knows that they're not in his language, but the way he says her name has always been declaration enough for her.

'You don't have to tell me,' she says, and she's surprised to find that she means it. 'Spoilers, I'm sure.' Her voice sounds brittle, even to her own ears, and she lets go her grip on his jacket, strokes one of his hands in apology.

He shudders against her touch, and she raises her head in alarm. 'Not this time,' he says, and his smile is twisted. 'Spoilers mean those thirteen years your parents raised you in the fifty-first century, thirteen years for you and a hundred eighty-three for me, those years where our timelines diverged.'

'Where future-me was popping in on you from time to time,' she says, trying to untwist that smile.

'River,' he says again, and he has her hands in his, so chaste and yet so intimate for a telepath, even one that keeps his defences up at all times. She sucks in a breath, looking into those old, old eyes. 'Have you ever wondered where our timelines diverged for the second time?'

Oh, she thinks, staring into the eyes of her Doctor, and of course she has, of course she has, but it can't be so soon, it can't be now, she's not ready, she's only had eight years, and she's not ready. The wind is howling at the door, the shadows shifting across the balcony, a strange burning crawling under her skin, and then he's dropping her hands and gathering her to him, and she feels herself begin to shake.

'How long?' she asks, an eternity later, her eyes still dry, her trembling hands the only clue to the weight which has settled somewhere inside her.

His eyes are sad as he traces her cheekbone. 'I don't know. Years, perhaps.'

'Or months, or weeks?'

'At least months, I think,' he says. 'I'm beginning to understand, but there's still a lot I don't know. I can't risk crossing my timeline and interfering with my own past until I know more.'

'Is it wrong for me to hope you never know more?' she asks, hearing the fierceness in her own voice, the fierceness she'd last heard on Natoka Kupenda, when she'd stood over his limp body and defied a small army with nothing more than fear, love, and a pair of pistols.

'Not wrong,' he says, and stands. She folds into the crook of his arm, standing snug against his hip, leaning her head back against her shoulder. In the last dying light of the sunset, as the moons freeze in the heavens, he says, 'But they're catching up to us, River. If I don't leave soon, it may be too late.'

I'd rather die than lose you, she thinks, but does not say. It is not something to burden him with, the being who has lost so many loved ones over his long centuries. She may be the one who has shared his bed, she may be the one (she hopes) whom he has loved the deepest and the fullest, but she does not pretend, even to herself, that she has been the only one to touch her Timelord's heart.

Perhaps it's not even true, she thinks, standing in the semi-darkness, feeling the outlines of his ribs under her fingers, the thud of one of his hearts against her hand. Dying would prevent the pain of losing him, true, but could she truly choose oblivion over memory? And despite the smiling 'Spoilers', she knows that she was (has been, will be) a frequent presence in his life over those hundred eighty-three years. Could she selfishly choose to die, knowing that her death would mean that those appearances would never happen, leaving him grieving and alone?

A movement catches her eye in the flickering moonlight. The creeping shadows on the far end of the balcony have resolved into a hunched figure, his head dropped in his hands, standing silhouetted in the near darkness. 'Look,' she says, and the word feels rough on her tongue. 'Another being, come to watch the lights of dead Aeterna.'

A moonbeam plays across the hair of the distant figure, and next to her, the Doctor's shoulders stiffen. 'What,' he says.

She fights back the urge to giggle, knowing from experience that it's likely to be the beginning of hysterics. 'We're not the only ones in the universe tonight after all,' she says, lightly.

The figure is not danger, she knows, or else they would already be back in the Tardis, standing silently behind them. (These days, they try not to venture too far from it, after Phomyak Prime. Although that's not always a precaution they manage to stick to.) She could have been fooled, though, from the tension in her love's body, from the way his arm tightens unconsciously around her waist.

After a moment, the tension breaks, and he is laughing, a slightly broken sound, turning his face into her hair, and she is not the only one near hysterics, she thinks. 'Only me,' he says, muffled.

'Only you could have found yourself in a situation like this?' she translates.

He shakes his head, still laughing. 'It's only me,' he repeats, then is overcome again. 'Only me!'

'Sweetie, you're not making any sense,' she says, deliberately using the pet name he pretends to hate but secretly adores.

He snuffles into her hair, and she rolls her eyes.

'I have the worst luck of any Timelord ever,' he says, and the laughter has faded a bit, even if the hectic edge is still in his voice. 'I'm getting ready to go back and cross my own timeline in risky and frightening ways, and of all the gin joints in the universe…'

'That's you,' she guesses. 'Not you you, though, from the look of things.'

'My last regeneration,' he agrees. 'I don't remember this, but he's here, and we're here, and the universe just loves us, doesn't it? It can't even give us this moment, on your birthday, without throwing the timelines in our faces.' He sighs, turns toward the Tardis. She can feel the tension in his limbs sagging under her fingertips. 'Let's go, River.'

She hesitates, looking at the slumped shoulders of the distant figure – perhaps not her Doctor, but a Doctor, and one that looks in as bad a shape as the one beside her, now tugging silently at her elbow.

'Doctor,' she says, and she feels the way he stills at the name, knows it means as much to him on her lips as 'River' does to her on his. 'It's my birthday, isn't it?'

'Yes,' he says, and she can hear the way he's trying to banish the defeat and sadness from his voice, the way he's trying to make himself sound happy, for her sake. 'Yes, it's your birthday – and this has been a horrible celebration, hasn't it?' He's picking up speed, finding his way. 'Let's go to Zvyodni. It's a little moon orbiting Toska, and you'll love it. It's covered in edible roses, taste like spun sugar and summer breezes, all the colours of the universe, except mauve, not a good colour to have in a rose garden…'

She smiles at the babbling, even though her heart aches a little. 'Doctor,' she says again, and he stops abruptly, holding himself quiet against her. 'If you're right, we only have a little time left together. Like this, anyway. We don't…' She breathes. In. Out. His smell, faint and addictive, reaches out to her. 'We don't have to talk about it again.' She looks up, finds his eyes in the darkness. 'But let's live every day as if it's our last. Let's not play it safe, or put anything off. Give me these days,' she says, and finds that she's pleading, her hands twisted in his shirt, her head tipped back, feeling like a faintly ridiculous character in a space opera, one she'd jumped into feet first back at New New Harvard eight years ago, and never looked back.

His eyes are searching, guarded, his body unmoving against hers. The silence grows between them for a moment, a living thing, and a shiver dances its way across her arms.

Finally, he swallows, and nods, jerkily. 'My River,' he says, and strokes a curl with the back of his fingers. She closes her eyes, and feels his breath on her face. It's the first time he's said that quite like that, and she thinks it may be the closest he'll come to saying what he can't say.

'What do you want?' he asks, his breath warm and slightly sour. 'Anything, anywhere, birthday girl.'

She breathes. 'Cross a timeline with me?' she asks, and cracks open an eye to see his reaction. His eyebrows have shot up, and he's frowning, but the frown hasn't reached his eyes. She takes a steadying breath. 'You said you met me in a past regeneration.'

'Spoilers,' he says, automatically, still frowning, but at himself now. She thinks he still hasn't forgiven himself for accidentally letting that one slip. She's very persuasive.

She smiles, just a little, and lets him see it. 'Well, if I'm going to meet you in a past regeneration, I'd rather know what you're going to look like beforehand. I don't…I think it would be hard for me, to accidentally meet an old you, without any advance warning at all.'

'You want me to introduce you to my old self,' he says, slowly.

'Yes,' she says, and shoves an inconvenient thought back behind her eyeballs.

Either he overhears it – which is unlikely, he tries to give her privacy – or she isn't successful at stopping the blush, because his eyebrows shoot up again. 'What?'

'Nothing,' she says primly.

Too primly, because he knows her too well. She sees him looking back and forth between her and the distant figure, and groans inwardly when his eyes flash in comprehension. 'River Song!' His voice is scandalised, in a way she's rarely heard before – he's usually impossible to embarrass. But he's flushing now, biting his lip, reaching a hand up to scratch at the back of his head, and it fits him, somehow. Sometime, sometime in the past, he was like this. Before me, she thinks suddenly, and bites back a smile.

'You want…to seduce me,' he says, scandal and amusement warring in his voice.

It's her turn to flush. 'It's just a fantasy, ignore it. I meant it about the introduction, though, I think it'll help me in the future…well, in the past.'

He's looking at her like she's a new person he's just met, or a specimen under the microscope, and she tips her head back and lets her eyes glitter at him, reminding him that she is more than that. She is more than a pretty face, a warm body, an open ear; she has darkness and unremembered dreams, and she will always be just a little outside his knowing, or indeed her own. She has killed things he would have let live – he has tried to dictate her life against her will – they have both put themselves in danger when the other would have rather had them safe. To love is not to completely understand, nor to control, nor to possess, but to trust and be trusted, a fierce intimacy in the face of the universe.

He licks his lips, and her eyes follow. 'When have I ever ignored one of your fantasies, River?' he asks, and his voice has gone rough.

Unbidden images flash through her mind, of thrown-back heads and sobbing breaths and the lick of leather, of dizziness and laughter and trust, of curves and hardness and the slip of sweat. 'There are things that might be a bridge too far,' she murmurs, letting her own voice dip lower, knowing even as she does so that this is a escape route from a conversation that has made her head swim. Later, she tells herself, later will be time enough, to think about what's been said, and to mourn what's to come.

He pulls her into a quick embrace, slipping his hand under her curls to cup the back of her head, fitting her into the curve of his side, mumbling something into her hair.

'What was that?' she asks, folding her fingers around his hipbone.

He pulls away, and his eyes are dancing, his mobile face animated again. 'Geronimo,' he whispers, and seizes her hand.

~/~

The figure ignores them as they approach. If he's anything like her Doctor, he's already looked the two of them over and dismissed them as a threat – they haven't been particularly quiet, after all, although he wouldn't have been able to hear what they were saying. Far below, the oceans of Aeterna II sparkle up at him in the moonlight, but his head is still buried in his hands, uncaring.

'Hello there, stranger,' she says, when her Doctor seems to have lost his voice.

The previous Doctor keeps his head down for a moment, before bringing it up and shaking his hair back, turning a smile toward them that looks more like a grimace. 'Hello.' His eyes are listless. 'I didn't expect anyone else to be here. Not with the explosion in an hour.'

'Explosion,' she says, giving her Doctor a stern look.

He bites his lip, pretending to be abashed. 'We'll be out of here by then?'

'I'll talk to you later,' she says, and turns back to the previous Doctor. 'Are you in the explosion business, then?'

'I wanted to be alone,' he says curtly.

She purses her lips. 'Rude.'

'Rude and not ginger,' her Doctor says, his eyes sparkling wickedly.

For some reason, that brings the previous Doctor's head snapping around, his eyes narrowing. 'What did you say?'

Her Doctor just hooks his thumbs in his braces and smirks at him.

They face off for a minute in the semi-darkness, silence taut between them, before she sighs. 'Boys.'

'Who are you?' the previous Doctor asks, hand twitching. Probably resisting the urge to go for his screwdriver, or bolt for his Tardis, which she can see half-outlined in the shadows behind him.

Her Doctor's smirk has gentled. Perhaps he sees, as she does, that this previous version is in some distress. 'Me? I'm the Doctor.'

A mere second of incomprehension, and then the other's face twists, convulses. 'Not again.'

'This has happened to you recently?' her Doctor asks, instantly curious, like a cat spotting a bird.

'Last week,' the other Doctor says. His shoulders have slumped again, as if a puppeteer has loosed the strings. 'The fifth me turned up.'

'Oh yes,' her Doctor says, grinning. 'Wearing a vegetable.'

'I imagine I won't remember any of this?' the other Doctor says, then goes on, ignoring her Doctor's nod. 'So what do you want?' He scrubs at his face with his hands. 'I assume you want something, or else you would have just left me alone.'

Her Doctor arches an amused eyebrow at her, and she feels the beginning of a blush. She's never been shy, but this is an odd situation. He's obviously in pain, and propositioning him doesn't seem like such a good idea any longer. 'I asked if I could meet you,' she says, giving him what she hopes is a friendly smile. 'Are you all right?'

He smiles back, eyes shadowed. 'I'm always all right.'

She finds herself stepping forward without quite meaning to, reaching out; she knows that particular lie. He flinches away from her outstretched hand, backing into the railing.

'River,' her Doctor says, softly.

She turns back to him, slips her hand into his, rests her forehead against his neck for a moment. It was a bad idea. To the Tardis, then, and off to the next adventure.

'You're together,' the other Doctor says from behind them, a note of bewilderment in his voice.

'I do usually travel with a Companion,' her Doctor says, pressing her hand. 'As you know.'

The other Doctor has pushed himself upright for the first time, eyebrows gone complicated. 'No, I mean, you're together.'

A moment's considering silence, then – 'Yes,' her Doctor says.

'But how...' He swallows. 'How...' Shards of incomprehension in his eyes.

She feels her Doctor's heartbeats speed up. 'Rose,' he says.

The other Doctor nods jerkily, as if it's torn out of him.

Her Doctor sighs, flutter of breath in her hair. 'I can't say it heals,' he says, simply, and she's a bystander to this, a part of his past which he's never told her – spoilers, he'd say, but also self-protection, perhaps – 'but it becomes bearable, in the end. We lose so many people to the pull of time, we have to learn...'

The other Doctor interrupts fiercely, 'Rose is...'

'Different,' her Doctor finishes for him, when he trails off. 'Yes. Well.' He clears his throat, and she feels her hand being gripped a little tighter. 'We never do manage to tell them that at the time, do we? Human language is so limiting and frustrating, never the right words, always something missing.'

'She was taken so quickly,' the other Doctor says, barely audible, confession and condemnation. 'I've tried to forget, I've tried to...and now you...you're telling me that you find someone else, and I don't know what to think.'

'There's a while before that,' her Doctor says. 'Years and years yet.'

The other Doctor turns away from them, looks out over Aeterna II. The oceans are starting to glow oddly, dark golden bubbles somewhere underneath their surface. 'She would have loved this,' he says, hand clenching around the railing. 'I can't forget her, even for one night. Some days it fades, but others I feel like I see her around every corner. It's been a year, and I still can't forget her.'

'Would she want you to?' River asks, and perhaps she shouldn't have, it's not her place, but she couldn't help it. She isn't jealous of this Rose – she knows how much the Gallifreyan at her side cares for her, even if he can never quite find the human words – but the careful set of the other Doctor's shoulders makes something in her ache.

He doesn't answer her.

After a moment, he turns back to them, face composed. 'You're brave,' he says to her Doctor, nodding to her, 'to risk yourself again.'

Her Doctor smiles, and there's a shadow behind it. 'I've always known that. But what would life be, if we refused to live it?'

'You're getting deep in your old age,' the other Doctor says, cocking his head, and he looks tired but less burdened than before. He turns toward his Tardis, then turns back. 'You're very pretty, by the way,' he tells her. 'I've always loved a woman with curves, and your hair is mesmerising, although alarmingly large. I hope he treats you well.'

She smiles at him. 'He puts himself in danger five times a week, which I could do without, but for the most part, yes. You might rather ask him if I treat him well.'

'Only five times?' her Doctor says in her ear, and she turns her face up to him, letting her smile reach her eyes. He kisses her, surprising her – he's not generally one for public displays of affection – and she kisses him back, open-eyed.

The other Doctor clears his throat. 'I'll be off, then.' He sounds strangely stifled.

Her Doctor raises his head again. 'Join us.'

The other Doctor's face is as mobile as her own's. A range of emotions chase themselves across his face in a matter of seconds. 'Afraid my Tardis might have something to say about that, if I abandon her here to go adventuring with a her from a different point in time,' he says, words running together. 'Besides, the name thing would be problematic, running around the universe with two Doctors, and then there's that whole bit about ripping the entire universe apart with the paradox, wouldn't want to destroy things, not after working so hard to keep them going...' He trails off.

Her Doctor smiles at him. 'Join us,' he repeats. 'Join us while Aeterna burns. Forget for an hour.'

The other Doctor's eyes turn to her, impossibly wide under expressive eyebrows, and she tries to look both comforting and a little seductive. 'If you want to,' she says. 'It's just an invitation.'

He swallows. In the silence, the odd roar of the oceans below reaches her ears.

'So you two go around trying to shag past Doctors, do you?' he says finally, voice getting high at the end.

She laughs. 'No. Just you, so far.'

'It's her birthday,' her Doctor says, resting his hand on her hip, offering the words like they're an explanation, or a bonus.

The gold light of the burning oceans trickles across the balcony, blending with the silver of the moonlight, chasing the shadows into the corners.

'Well then,' the other Doctor says, and takes a step away from his Tardis. Swallows. Takes another. 'Wouldn't want to disappoint the birthday girl, would I?'

~/~

Bodies and flashes of gold, warmth and stars and the light of the moons, spirals of desire and the sharp angles of two lanky bodies folded around her curves. A Doctor's mouth pressed to hers and another's pressed somewhere else; gasps for air, and shouted prayers. Aeterna, burning. River, burning.

A Doctor's shoulders shaking, face turned into her neck, hips thrusting slowly; she feels tears slipping down her skin, but gives no sign, beyond pulling him closer.

Hello and goodbye, goodbye and hello, a stolen hour in the knotted tapestry that time has woven them. She clings to them fiercely, delighting in every flush, every moan, every thrown back head and bitten lip, every glazed look of wonder and half-voiced endearment. She seizes the joy and love and passion and holds them to herself, talisman against the shadows, defying the trickle of the hourglass. If the dark is to come, let it remember this, let it remember the brilliance of the light, when she lay in her lover's arms.

Soaring so high she can hardly breathe, the oceans beginning to explode far beneath them, percussive sounds underneath the sobbing breaths of three time travellers. Starlight in her eyes, burning shadows, the blinding flash of ecstasy. She is going blind.

They hold her as she shakes, arms twined around her, four hearts beating irregularly against her own, pressing kisses everywhere they can reach.

~/~

long ago in the future

'I've come from the Doctor too,' her father says, wearing a Roman costume and looking impossibly young, standing outside her prison cell.

'Yes, but at a different point in time,' she says lightly.

He nods. 'Unless there's two of them,' he says, half ready to believe that perhaps there are.

'No,' she says, putting a world of memories into her smile. 'That's a whole different birthday.'

She walks away, toward her cell, and he blurts out behind her, 'He needs you.'

And she cannot go.

~/~

She shoots the Stetson off his head, because she can, because she misses the days when he knew her, because she doesn't want to go any earlier in time, she doesn't, because she'd hoped against hope that Demon's Run would somehow break the timeline, would somehow rewrite time and free her to live her life at his side, and it hadn't.

Time continues, backwards, inexorably, trickling toward the day when he won't know her, toward the day when she'll lose him forever. Or will she lose herself?

'Hello, sweetie,' she says.

But unexpectedly, this is one of the beautiful days, the days when time hasn't gone backward in quite such a straight line, when they meet out of order. He knows her, and his smile has the slightest edge to it, hidden when the Ponds are looking, because he knows who she is and was and will be, and they don't yet. The two of them sit across a table from each other and do diaries, and she can barely contain her smiles, can hardly keep from climbing across the table into his arms, Ponds be damned. (She still has trouble thinking of these Ponds as her parents – they are so young, and unshadowed, and unparentlike. She feels like their older sister.)

She's so busy trying to keep her joy hidden from Amy – sitting across the table, next to him, in her spot, but it's ridiculous to be jealous of one's own mother – that she barely notices a funny warning sign, right at the edge of her vision, trying to get her attention. It's only later that she thinks back, and realises that he wouldn't look at her, not properly, that his eyes skittered away from her, as if she was a sun and his eyes unprotected.

'I've been running,' he says to Amy, 'faster than I've ever run.' He looks at her full-on, for one precious second. 'And I've been running my whole life. Now it's time for me to stop.'

Her head comes up, slowly, her eyes fixed on him. There's something here she doesn't understand, not yet, something that she should understand. Amy's asking for details, but the details don't matter; there's something here that he's hiding, and she doesn't know why.

A picnic on the edge of a lake, and she sips wine and watches him, lying so close to her and yet so far.

'I'm eleven hundred and three, I must have drunk it sometime,' he says, false casual, and she comes back from far away, hears those words over a sudden roaring in her ears.

Eleven hundred and three. He'd left her, ages ago in the future, in the forest of her childhood, when he was eleven hundred and three and she thirty-two. The Tardis had taken them there, and he'd stepped out onto the forest bed, chattering happily over his shoulder, and stopped dead; she'd seen the final piece of the puzzle slot into place, deep in his eyes. He'd made love to her one last time, under the trees, which whispered their hellos and goodbyes far above their heads. He'd pressed his face into her shoulder and kept it there for a long moment, her hand fisted fiercely in his hair, mindless of the pull. He'd looked up, his eyes glittering, searching for words, and she'd smiled at him – there at the end that wasn't an end – because they didn't need words, not the two of them, and never would.

He'd left her there, on his way to cross his own timeline and make it happen, all at once, the wibbly-wobbly timey-wimey she'd never quite understood, except that it had happened and therefore it must. To save her parents, and save her, and save the universe; and she'd stood in a forest clearing, tears brimming behind dry eyes, hands fisted in her skirts, hearing over and over the echo of the last thing he'd said, finding the right words at last – his name, whispered in her ear, his parting gift and deepest truth, to keep her company over the long years voyaging backward through his timeline, never alone and yet always alone.

There have been good times and bad times, in the years since, as their timelines cross and recross, never lingering. She's watched him grow younger, watched him know her less and less; and none of these Doctors are hers, the one who spent those eight years with her, roaming the universe. None of these Doctors watched Aeterna II burn, the moons turning blood-red at the last. These Doctors know her only from the older her that has popped into their life from time to time. They are still her love, still her 'sweetie', and she treasures every day they spend together, but she misses him, misses the one she's lost.

And now here he sits, eleven hundred and three, and there's a universe of questions whirling in her mind, a lifetime of tiny heartaches and bitten-back words somewhere in her chest, a Gallifreyan name on her tongue.

He's not looking at her, he's making uneasy, brittle banter with Amy, and she wants to shake him, to kiss him, to bury her face in his chest, to hit him – but he left her when he didn't want to, left her for a reason, and that reason must be here. She can't interfere, can't destroy their shared sacrifice; so she lies still, and sips her wine, and waits to see what he's planned.

They talk of the moon, a single moon, hanging over them like a scythe.

A space suit rises from the lake, and she springs to her feet. 'Oh my God,' she breathes, childhood nightmares surging somewhere deep inside, the past her parents (the parents even now jumping with surprise) had refused to tell her about, the past she'd forgotten, or chosen to forget.

He walks forward (she is frozen), tells them to stay back. 'Whatever happens now, you do not interfere,' he says, and that is for the Ponds, rushing into danger without looking first.

And then he looks back, past the Ponds-who-will-be-her-parents, to her. 'Clear?' he says, meeting her eyes properly, and she knows, somehow, what that means, and rushes forward.

But he knows her too well; he knows she will watch him walk to meet his fate, whatever it is. He trusts her – and she forces herself to stop, the light of that one moon cutting through the sunshine, too bright in her eyes.

The gunshot.

Amy screaming, Amy running, must hold Amy back, must let her Doctor do what he must, even as her heart breaks.

The second gunshot.

'Doctor!' Amy screams, and he looks toward them, regeneration energy already starting to pour out, looks past Amy and straight to her. I'm sorry, she hears him say, even though he's much too far away for his voice to carry.

The third gunshot.

~/~

He's there, sauntering through that door as if he hasn't just broken her heart. He greets Amy and Rory first, true affection shining through, and then turns to her, with intrigued amusement the only emotion showing in those eyes. 'And Doctor River Song. Oh, you bad, bad girl, what trouble have you got for me this time?'

She cannot bear it, she cannot bear this, not this, not when she has just burned a part of herself, out there on the lake. She slaps him, good and hard across the face, and thinks above the roaring in her ears, that perhaps this was how that other Doctor had felt so long ago, that night they had comforted him in their arms. The person you love dies, and a Timelord – even a half Timelord – has to go on, has to bury them and keep on saving the universe. And it's hard, it's hard, it's too hard...

'I'm assuming that's for something I haven't done yet,' he says, as she tries to keep the shock and heartbreak out of her eyes. Even dead, he is asking her to do the impossible.

'Yes, it is,' she says.

~/~

She kisses him, and it's the last time.

He's nearly a stranger now, a stranger in her true love's face.

~/~

Whatever plan he had, she doesn't know if it worked or not. She hopes against hope that she has a nonlinear moment left, a moment when she escapes her general backward trajectory and hops forward a bit, just a bit, to see a bit of middle again, instead of the beginnings.

It doesn't come.

~/~

She's in a singularly unflattering spacesuit, and he's wearing his old face, the face she saw on Aeterna II, back when her heart was whole. She feels so old now, so brittle, but she summons up her memories and smiles at him. 'Hello, sweetie,' she says.

'Get out,' he says, and for the first time, his eyes have not the slightest flicker of recognition in them.

It's the beginning, then, his end of their beginning, and her heart thrills and breaks, all at once.

She knows it's even chances, at best, that she'll make it out of this one alive. Perhaps she'll hit the beginning and go skipping forward again – that would be lovely; or perhaps this will simply be the last time she'll see him, and she'll keep living, but a life devoid of him – that would be the opposite; but even chances, or better, say that this is her end, here at the beginning. Time is poetic, sometimes; it whispers to her, in the darkness, taunts or blessings or cryptic prophecies.

She throws her head back, hears a much younger voice in her ear. Let's live every day as if it's our last. Let's not play it safe, or put anything off. Give me these days.

'Pretty boy!' she calls. If these are to be her final hours, she'll live them to their fullest.

'You're doing a very good job of acting like you don't know me,' she says, clutching at her last hope, keeping a brittle smile on her face. She flips through the pages of her diary, vision blurring, calling out places, memories, talismans against the dark.

He watches her in silence.

She looks up, and is caught. 'Your eyes,' she breathes, and has to reach out and touch, going against all her rules, but if this is the end, then rules are perhaps not as important. Or is it the beginning, and rules more important than ever? 'You're younger than I've ever seen you,' she says; or perhaps a touch older than the other Doctor on Aeterna II, but near enough.

'You've seen me before, then,' he says, warily, and her last hope flies.

'Please tell me you know who I am,' she breathes, but she knows better, even as she says it.

He looks at her, uncomprehending, and breaks her heart, for the first, or last, time. 'Who are you?'

~/~

He'll save them, even if it kills him, and that would take him from her forever, in all time, in all space, perhaps even in all memory. She might wake up tomorrow, alive, but without any memory of the unconventional, infuriating, beloved Gallifreyan who has shared her life. She might wake up tomorrow a different person, someone who is not herself, and never could be.

In the end, there's no choice to be made, and it's a comfort.

She punches him – her father'd taught her that one, when she was nine, in their garden on Krohtua, with baby Henry crawling nearby – or was it in those shadowy childhood days she can't quite remember, the silent recesses of her dreams, when she was a weapon in training – timelines collapsing, coming to naught –

She handcuffs him in place. She kisses his forehead, blessing and farewell all at once.

She straps in.

At the end, with a minute and a half remaining to her, his wide confused eyes pleading for answers, she breaks. She loses her forced blitheness, loses her resolve to make it as easy for him as possible, saying goodbye to a her he barely knows. She tells him the story of Derilium, their last time together; she'd thought it a present from the universe, a precious moment in the fabric of their lives. Now she wonders if the lover who cried in her arms that night wasn't, perhaps, eleven hundred and three, breaking his own rules, and she doesn't know how she didn't guess.

She tells him the story, fighting against the coming dark, summoning up a memory to hold to her, in place of his familiar stranger's eyes.

'Time can be rewritten!' he yells at her.

'Not one line. Not those times. Don't you dare,' she says, and summons up the last of her courage. 'It's okay,' she tells him, and through him tells the Timelord she loves, down the long pantheon of years.

'You and me. Time and space. You watch us run,' she says.

'Spoilers,' she says, and the light comes.

Their timeline ends – and begins.

~/~

He saves her, to live in Purgatory, a Purgatory without him, for all eternity.

She hates him then.

She cannot even dream of him, trapped in nothingness, outside of space and time, doomed to spend eternities of waking moments without him.

And yet she cannot shake the shadow of hope, lurking deep in her soul.

Some days it makes it worse. Some days it's all that keeps her going.

~/~

Light.

The lights of Aeterna, moons and starlight and burning oceans, an eternity of time and space, encapsulated in a single moment.

Has she at last been granted a dream? she thinks wildly, even as her heart surges into her throat at the sight of him, standing so quiet before her. She doesn't dare to hope, lest it be ripped away from her again in the next instant. She drinks in the sight of him, memorising him once again, to sustain her through all the infinities to come.

They stand in silence, together in the light. She is afraid to stir a muscle, afraid to break the dream, afraid to plunge once more back into her living death, into the cool white memory circuits of the computer.

'River,' he says, and his voice rips the silence, top to bottom, and something stills, deep inside her.

'River,' he says again, and a sudden terror and a terrible joy threaten to split her in two.

'How old are you?' she whispers, and finds that her voice is scratchy with the weight of tears.

He smiles at her – a gentle, old smile; the smile of the Oncoming Storm Triumphant; the smile of a Timelord who has fought across time and space to reach her, even as she, half-Timelord, has given her life to preserve the past and future existence of their lives; the smile of someone who has come home.

'I'm eleven hundred and four,' he says, 'and you...'

His voice cracks, not as calm and sure as he looks, and she's stumbling forward, into his arms at long, long last, and the silence and shadows fade forever, as he whispers in her ear, broken and whole, 'You are my River.'

'And you,' she whispers back, clinging to him with all that's in her, as he clings to her just as tightly, her parents in the background, young and lovely and shy, 'are late.'

~/~

My beloved spoke, and said to me, Rise, my love, my fair one, and come away.
For lo, the winter is past, the rain is over and gone.
The flowers appear on the earth; the time of the singing of birds is come...
My beloved is mine, and I am his.
Until the day shall break, and the shadows flee...
Arise, my love, my fair one, and come away.
- from the 'Song of Solomon'