Disclaimer: I do not own Doctor Who, or any dialogs or lyrics quoted here.

What if you knew a world where the laws of physics didn't apply? Where there was something with a speed much greater than that of light, where time travel was possible and happening, where every choice you made lead to different futures? What if you could see these futures spread out in front of you? Millions of timelines, twined together like helixes of DNA, each unique strand visible right in front of your eyes?

If you could know the consequences before you performed the action, if you had that chance, if you had that choice, wouldn't everything be so easy?

"If you could replay this, where would you stop to untie your hands?"

There's a distinct possibility that he has got himself into trouble again, but she tries not to worry about that, instead focusing on the lovely view of seventeenth century London from the balcony. She sees the city, the buildings, the people, beyond the thick wall of trees surrounding this abandoned mansion that the TARDIS crash landed in, and a part of her wants to just go explore without the Doctor. She can take care of herself, did so in the parallel universe for years and found a way back home without any help. She will be alright, molto bene. Oh, so she's now picking up his lingo, brilliant- and another word of his, yay.

Gown scraping across the tiny path leading to the avenue, thankful that the long bell-shaped skirt is doing a fantastic job of hiding the bright pink converses that so do not fit into this century, she creeps through the woods, praying the herbs are not poisonous or itchy, when a shadow passes by for a fraction of a second. She would have chalked it up to mere imagination amplified by the spooky atmosphere around her, if not for the fact that she's seen worse and isn't easily scared, and is rarely wrong about these things.

"Who's there?" She calls, and when there's no reply, she takes a step forward towards the general direction of the shadow, and asks again.

When there is still no reply, she suddenly remembers the story of the entity still free in midnight, appearing as a mere shadow till it learns to mimic and adapt and take over, and a cold chill runs down her spine.

So she is almost relieved when a girl steps out from behind a bush and regards her with curiosity.

"Oh, hello there", she breathes out. "I'm Rose. Been exploring the place. I reckon you are too?"

"You speak in such a strange and eccentric manner." The girl, who can't be more than eighteen or nineteen, says. "It reminds me of somebody I once knew, but I am not certain of whom."

"Okay", Rose says, unsure of what to say, and once again she regrets not spending enough time on history lessons to know how to speak.

"I am me." The girl says.

Rose laughs. "I can see that. But what's your name?"

"No, that is my name. I call myself Me." The girl says, and waits for Rose to ask the questions that she has been asked so many times before, and it takes her by surprise when she doesn't. "You don't seem startled by this at all like the others."

Rose smiles. "Trust me, it isn't the weirdest name I've heard. There's this bloke of mine. Calls himself the Doctor. Just the Doctor."

Me's eyes widen in a strange mix of recognition and fear and hope and anger, and she loses a little of her composure. "You know the Doctor? Is he old, wrinkled, with grey hair, and carries some kind of black magical glasses?"

Rose mentally thinks over the previous incarnations of the Doctor, and realizes none really fit the memo. She laughs at the thought of the fit her Doctor who throw if he thought he would look old someday. "No, he definitely looks young and not wrinkled. He sort of has brown hair. Really, really great brown hair. And sorry, but plain old black rimmed glasses. Looks really hot in them though."

"How can a person look hot?" Me asks, now certain that the Doctors they are talking about are indeed different.

Rose kicks herself mentally again for her slip of tongue, and prays that the Doctor and Me never meet and she never tells him she actually called him hot out loud, because if that ego of his expanded even a tiny bit more, she is going to explode. "Never mind", she says, and decides to change the subject. "So what are you doing here?"

Me responds with a slight tilt of her shoulder. "I live here."

Rose laughs at the joke, and when she realizes it isn't a joke, she's filled with concern for the girl. "What? On your own? In this creepy place? Where are your parents?"

"Dead, I suppose." Me says, with the clear lack of emotions clouding her face.

"I'm sorry", Rose says, remembering her own family in the parallel world and feeling a familiar pang of longing for them.

Me merely nods, courtesies, and disappears behind the trees again before Rose has time to offer her to travel with them to some place more suitable for living for a young girl her age.

She doesn't have long to think about it though, because the Doctor comes running in her direction soon. "You will never believe who sent me a message on the psychic paper."

"River Song?" She guesses easily, spoiling his fun oh-so-intentionally.

He scowls in mock hurt, and nods in affirmation, before he continues. "She sent me two actually. First one says Clara's in trouble, come help."

"Who's Clara?"

"Don't know her yet." He shrugs, and continues. "Not to worry. The second says never mind, wrong Doctor. Oh, well, now that that's done, let's get out of this place, nothing to do here, I'm so bored, come on!" He hops on his feet impatiently, and she shoots him a glare.

"I'm wearing a bloody gown. You go, prepare the TARDIS. I'll be there in a mo." Before he can protest, she shoots him another glare, and he slumps his shoulders in defeat and leaves, mumbling something under his breathe about bossy Tyler women that she chooses to ignore for the moment. First, getting to the TARDIS in this god awful sorry excuse of a-

"Did he say Clara?" Me is suddenly back in sight, obstructing her path.

"I think so?" Rose says, feeling suddenly intimidated by the dark pit of raw fury in Me's eyes. She sees a flicker of recognition and hesitation, and then it all happens too fast.

Me shoves a piece of white rectangular something inside her forehead, and it disappears beneath her skin, leaving her with excruciating pain, till the world behind her eyelids turn black.

"Sometimes the sky is piano black- piano black over cleansing waters."

When she opens her eyes next, she's in the Med Bay of the TARDIS with a concerned looking Doctor by her side, staring at her.

"Don't say it." She warns, trying to sit up and finding that she can and nothing hurts. That's a good sign, she notes.

"I told you not to wander off. Why do you have to be so jeopardy friendly?" He scolds, completely ignoring her threat. "Now tell me what happened there."

She does, and sees the oncoming storm cast a shadow on his face with every detail she narrates. Finally, she gathers enough courage to ask. "I feel fine. You fixed it, whatever it was, right?"

He shakes his head, letting out a hollow chuckle that hits her in some sharp corner of her chest. "I can't fix it. I made it."

"What?" She asks, confused.

"That's a Myre medical kit, reprogrammed for humans. I reprogrammed it and gave it to that girl sometime in the future."

"How do you know?" She interrupts.

"Because nobody else is brilliant enough to do it", he says sadly, and cups her cheeks in his hands. "I'm sorry, Rose. I'm so sorry."

She feels a little scared at his words, but more brave, because her doctor can never reprogram anything into a terrible weapon. "What does it do?" She asks gently.

He searches her face for reassurance, and gets it in the form of a soft flutter of her eyelashes. "It heals the body, from within. It means you'll never grow old and never die."

"Like Jack?" She asks, and he hisses involuntarily, and they both smile for a moment, before the gravity of the situation dawns on her, as does the sea of possibilities it opens up. "That's not a bad thing! I can be with you forever this way."

"You don't understand", he says, his hands shaking with the fear he feels inside. "Humans are not supposed to live forever. I don't know how you will react to that."

"Humans are not supposed to look into the heart of the TARDIS either, but when has that stopped me?" She counters. "Stuck with you, that's not so bad", she teases, covering his hands with her own, and giving him a soft smile.

"But Rose-" he tries to protest, but she silences him with a kiss.

"I made my choice a long time ago, and I'm not gonna leave you." She repeats, and he really wants to believe her, because even though he has lived long enough to know that everything eventually ends, and the longer it lasts, the worse the outcome, and the more the pain, and even though he is scared of the consequences, Rose Tyler is the one thing in the Universe that he believes in, and he chooses to hope that she will surprise him again.

"Still I write my songs, about that dream of mine, worth everything I may ever be."

The first few years are great. She jokes about the lack of wrinkles and bad eyesight and aching limbs and how she doesn't have to worry about him going after a younger model, and he jokes about how they have an age difference of nine hundred years and that's as young as it gets and he's an alien who abducted her.

A mayfly mutated to live forever is still a mayfly though. The first leaf falls off the tree one day when they escape a prison in an alien world, after just a little over a hundred years of togetherness.

"That was close", she pants, leaning against the TARDIS wall, and he plops down on the floor from exhaustion.

"Yep", he says, laughing. "Jackie would have killed me if she knew."

She lets her own laughter die down before she asks, "Who's Jackie?"

There's a place in his brain that stores thoughts of his personal hell- Gallifrey burning, people dying, people leaving, worlds ending- the worst things that did happen to him and the worst things that could happen to him. In that place is a special space devoted entirely to Rose Tyler, and she just ripped off the first page.

"You don't remember Jackie?"

She shrugs in response. "Someone I knew? A friend?"

"She's your mum", he says hopefully, and the lack of recognition in her face and the resultant look of panic punches him deep inside his very being.

He pulls her into a hug, and she holds on tighter, afraid that if she lets go, he will disappear.

Or worse- she will.

"She's lost in the darkness, fading away- I'm still around here, screaming her name."

It happens at a slow yet steady pace. The human brain cannot store so many years' worth of memories. After she realizes she's forgotten her family, she starts maintaining a journal of the things that happen to her in hopes of remembering, but when she flips through the pages sometimes in the middle of a particularly boring decade, she can't remember the places and the faces at all.

It hurts for a while, but she gets used to it. She still has him by her side, and they still have adventures all the time.

"How did we meet?" She asks him curiously one day.

He's a little heartbroken that she doesn't remember, but he loves her enough to tell the story with a fond smile on his face. "I saved you from a bunch of alien mannequins, no big deal."

She rolls her eyes, because even if she doesn't know herself so well anymore, she knows him enough to know that isn't exactly how it happened. "And then how did you get into trouble?"

He tugs at an ear guiltily. "They kind of had me in their grip under the London eye. You kind of rescued me from them."

She laughs. "The high and mighty time lord, saved by a-", she pauses, and her next words strike a matchstick against his heart-shaped flame. "How old was I back then?"

Another dead leaf on the ground- he's lost count by now.

"Blackened below, the river now flows, a stream on molten virgin snow."

He has always been mesmerized by the beauty of creation. He has watched planets being formed, rocks and lands taking shape, soil peeling off layer by layer by layer. Now it kills him to watch it happen to her memory and her identity.

Rose Tyler, the stuff of legends, becomes a legend to herself, fading into obscurity with each passing century, until all that is left is a shadow of her that wears her skin and acts so different.

She doesn't cry for days when children die, she doesn't blink before she picks up a gun against a tyrant; she lets her hair grow its natural shade of ginger and forgets that she ever used to dye it blonde, and she tells him Rose is a really cheesy name. He wants to scream and run away, but instead he holds her close to his chest every night and listens to the steady rhythm of her heart-beat while she sleeps. These are the times when he can pretend that she's still her, and he's still him, and everything is A-Okay.

"Walk the dark path, sleep with angels, call the past for help.

Touch me with your love, and reveal to me my true name."

She knows she is losing herself with every passing day. There's not a strand of grey on her hair, and bright pink sweaters in her closet that she hates and doesn't remember buying mock her. She smashes her mirror in a melt-down when she finds a picture of herself with the Doctor that she can't even remember taking, and punches the wall when the horrible thing inside her fixes her bleeding hand just to feel the physical pain.

Because that's all she feels, that's all she knows. She loves him, she's sure. Something rooted to her core is entangled with the fibre of his existence, and she is so glad that she is in this with him. But the core is eroding away, and he feels like a stranger every time he tells her another story about a stranger named Rose Tyler.

A thousand years later, per the records of her journal, she starts to feel bored of their routine. She doesn't remember the places, but she knows she' been here and done this before- it all fades into a giant blur of familiarity. And familiarity does breed contempt.

The first time she is really scared, though, is the time when she finds herself kissing him with her eyes wide open. She knows she's supposed to feel love and joy and everything that feels so alien to her now, and it hurts that she doesn't, that she cannot.

She holds his hands a little tighter after that, afraid of slipping and falling into a pit of nothingness. There's a feeling of familiarity here too, like she had been about to fall into a void far away from his outstretched hands sometime in her past, and she hates how she cannot remember it.

There's a long monotonous stretch of time when she does what she does because she knows that's what she's been doing since she can last remember. A few more centuries pass till she grows tired of his constant blabbering and input of wrong co-ordinates and magnetic attraction to jeopardy and flirting with women and mirth at dangers. The pages of her journal tell her that these are some of the many things she adored about the man she loved.

Loved. She notices suddenly. Past tense. And then the choice isn't even a choice- it's an inevitable decision.

"Take me back", she demands, and he looks so shocked that she has to explain. "Take me back to my home, my time. I want to see who I used to be."

He looks ancient and weary, and she notices that he's been aging through these years, albeit slowly, and it's like a slap to her flawless ageless face. She bites her tongue and holds back the tears of frustration, as he explains all the reasons why that isn't possible. "We can't cross our own time-lines, Rose."

She takes a threatening step towards him, chin held him with determination. " ' ."

At first he looks like he will put up a fight, but he surprises her by relenting. "Okay, but you can just watch from a distance. No interaction whatsoever."

She nods, and gives him a hug from sheer happiness, and when they pull back, she sees his eyes water a little in what she guesses is nostalgia.

It's the longest two minutes of her life till they land. London, Power Estate, 2005, New Year, right before they meet, he tells her, and she walks into the snow with the hope and faith of an amnesiac viewing an old tape to try to spark some distant memory.

She's a little disappointed when she doesn't recognize the place at all and feels nothing for it, and before she can talk to the two blonde women coming from a distance, the Doctor pulls her away hastily. It takes her a few minutes to realize that the younger blonde giving her mother a pep-talk about the possibility of finding love again is her.

Her. Warm, compassionate, strong, with an unfamiliar accent, a tongue-touched smile, foreign hair and clothing, and everything about her that she does not recognize. She feels so miserable that the sobs refuse to come.

She feels the Doctor take her hand, and looks up to see love for her shining in his eyes. Even after all these years, all these changes, when she isn't even the girl he fell in love with, he loves her, and she? She doesn't even remember him, doesn't feel anything at all. She suddenly envies the girl she just saw, she had the one thing she would die for- the ability to die, how ironic.

"You can't talk to them", he reminds her.

"What happens if I do?" she challenges.

He never does answer her without mystery. "Something bad."

"To you or me?" She demands.

"To me." He says without hesitation.

"Because you will try to save me." She concludes. "Well, if you really do love me, and I know you do, then don't."

"Rose!" He protests, giving her hand a squeeze and tugging her closer to him. "Don't you dare!"

She isn't afraid anymore, of him, or of death. "Do you love me enough to let me die?"

"Rose, please", he begs.

But she is not that girl who is walking towards the building with her mum, the girl who would put others before herself. She is a human who has lived far too long and lost far too much to care- she's the woman who reaches out and touches her old self.

Old her looks confused and concerned, the Doctor looks terrified and broken and pained, but she just feels peaceful as the reapers come, and she gives him one last smile after oh so very long as she is finally freed from the prison of life.

"As I am soaring I'm one with the wind…."

Forewarned is forearmed, or so they say. He knows a world where the laws of physics don't apply. Where there are things with speeds much greater than that of light, where time travel is possible and happening, where every choice he makes lead to different futures. He can see these futures spread out in front of him- millions of timelines, twined together like helixes of DNA, each unique strand visible right in front of his eyes. There's a time line where Rose lives forever until she isn't Rose anymore and decides to end her miserable life.

And there's another where she's happy with the other him and her family in the parallel dimension, fish and chips, running, rows, dishes, mortgage, slammed doors, kisses- all in a happy picture frame, while he goes on with his lonesome life, and though it is dangerous to see his own timeline, he catches a glimpse of some version of him fighting clock-work droids, holding a bunch of roses in his hands, and not remembering the love of his life.

The choice is very difficult after that, like every right thing in the world is, but at the same thing, it is extremely easy, because he would put her happiness before his any day. And so he steals a glance at this fleeting moment of happiness- Donna, Martha, Mickey, Jackie, Jack, Sarah Jane, the other him, and Rose, all the people that matter to him in his TARDIS, and programs the second last destination into the computer- the place where she stood on the worst day of his life when he burnt up a sun to say goodbye.

Bad Wolf Bay, parallel universe. "Does it really need saying?"

"And it would break your heart, well, if you knew, that this is all about you."

Lyrics from Barbarossa, Nightwish, Within Temptation.

A/N: This plot bunny wanted to be written, so here it is. I managed to make myself cry, so yay. Reviews are very much welcome and appreciated. Thanks for reading, and I'm sorry, I'm so sorry!