Disclaimer: I do not own them.

Author's note: By far, this is the darkest thing I've ever written. It was... an experience, to say the least.

Everyone tells her she's acting like him.

(Most days, she just wants to shout "good" and be done with it. But that would be rude, and she's not acting like him—not on purpose, anyway—so she doesn't.)

She and Mickey can barely speak anymore without getting into a fight—him telling her to move on, or slow down, or just take a second to breathe and not think so much, and her not wanting to hear it. She doesn't have the words to say that she can't breathe: that the air isn't right in this universe, that she's gotten too used to the pace of a double heartbeat and everyone else moves too slow for her. Jackie, on the other hand, just worries and fusses and forces her to eat and to rest, and occasionally cleans her flat when she pulls all-nighters at work. Rose doesn't have the heart to tell her to stop, so she lets Mum have at it and just reorganizes the piles back into clutter and mess the day after. She can only spend so much of her time looking for things that aren't in front of her, after all.

(Sometimes she wakes up at her desk—having fallen asleep over blueprints and physics textbooks—to find the open document on her laptop covered in the same two words, over and over. Familiar words she doesn't remember writing. She lets them encourage her all the same.)

But it's just that… well… she feels like him—or at least, what she imagines he feels like. Everything is manic and urgent and right now, and she's entirely unused to the anxiety of it. Her mind is racing, racing, racing, all the time, and she's scared that if she pauses—even for a second—something will fall out. Get overlooked. It's like having a word on the tip of her tongue that she can't quite grasp, only it's constant and it's everything and she's sure she's felt this way before, only it slips from her memory (like everything else) when she tries to hold on to it. Like levers and words and fingers.

(Sometimes she wakes up to phantom caresses, her nails digging desperately into her mattress in an attempt to capture the ghost of his hand in hers. These panicked moments in the small hours of the morning scare her most of all, because one day, she knows, it will feel less like waking up to a nightmare and more like waking up from one. She plans to fight that transition as long as she can.)

The routine would be soul-crushing if it weren't the only thing keeping her afloat. Every day she climbs the 50 stories to what used to be the lever room; the industrial practicality of the banisters and clinically pristine whitewash of the walls lend structure to her days even as they close in around her. (When people ask her why she never uses the elevator, she tells them it's because the stairs keep her in shape. Which isn't a lie, exactly—but it's not the truth, either. The stupid, embarrassing truth of it is that she can't bear getting into small boxes that are the same size on the inside.) It's been years, now, and though she still can't particularly say that she likes Torchwood, she's perfectly willing to admit that she needs it. Needs to be useful; needs to feel needed; needs to have contact with things outside her own world.

(Sometimes she never wakes up at all: just goes through her day like a somnambulist, lost in her own thoughts. Deaf to the muffled questions and blind to the concerned glances thrown at her. She's never compared to the Doctor on days like these, and she's grateful for the silence.)

No one ever says them to her face, but she knows her team has nicknames for her—classroom sobriquets stage-whispered behind her back. Her favorite—overheard in the break room as she'd fixed a cup of tea—is The Ghost. She understands why they'd say it, of course, but… it's almost funny, how far from the truth they are. (What she wouldn't give to be able to walk through walls.)

After a while, she learns not to mind the mania. She still feels more like him than herself, but at least that's feeling like someone. When she'd first arrived—after the fall but before the beach—she'd all but disappeared; the color in her cheeks and the twinkle in her eye had faded as fast as breath on a window. (She still hasn't gained back the weight she lost during those half-remembered days of hazy depression.) Any attempt to embrace her new life beyond mere endurance had felt like a betrayal; her loyalty the only piece of him she had left.

But then he'd said "you can't" and he'd very nearly said something else, and everything changed.

She never gets comfortable, but she manages to adapt. Learns how to breathe through panic attacks; relearns how to look people in the eye when she speaks to them. When she doesn't have the words she learns those, too, or makes them up, and then gets upset when people salute her for it. It's an insult, though she knows they don't mean it that way. They're hailing someone who isn't really there; congratulating her for losing herself entirely, paying respect to a shell with borrowed mannerisms. It's sick. (She's sick.)

She meets a lot of doctors. None of them nearly as brilliant as her own, of course, but she never expected them to be. Pete flies them in from all over the world—the brightest minds, each on the cutting edge in their fields—and they sit at the Tyler kitchen table and teach her over tea and biscuits, like Mickey had so long ago when he'd tutored her for her GCSEs.

She wishes she'd paid better attention to all the Doctor's mad rambles about trans-dimensional physics and temporal folding and god knows what else. It's easy to drive herself mad thinking about it: that maybe, just maybe, he'd told her the answer to it all while he was opening the jam jar, and she'd been too busy making toast to listen. Whenever she's stuck at work (whenever she misses him, which is always) she runs through their conversations in her head—looking for clues, looking for comfort.

It's absurd, the kinds of details she can recall if she concentrates hard enough.

"Well all that stuff you hear about 'the fabric of reality' and ripping holes therein," he'd said when they'd returned from Pete's World the first time, his legs on her lap as they'd lounged on her couch at the Powell Estate, "it's not half bad, as metaphors go. Universe as textile. It's like… imagine a canvas. Or a curtain. Day to day wear and tear, that's not a problem. Universal boundaries and curtains are equally likely to fray a bit with age. But every once in a while, something big will happen—you'll slam up against it, or some nutter takes a razorblade to your drapes—and then it'll need fixing."

"But… that's what we do, isn't it?" she'd asked, trying her best to follow along. "We fix the holes."

"Well, yes. But also no. I'm a Time Lord, Rose, not a… a Space Lord." He'd frowned, and she'd laughed at him. "The kinds of problems we fix—making sure that the Fourth Great and Bountiful Human Empire is actually as great and bountiful as the textbooks say it's supposed to be, or—"

"—or making sure people die when they're meant to," she'd added quietly, her proper father fresh in her mind after her encounter with the Other Pete. He'd taken her hand, then, and pulled her across the sofa so that she was practically on top of him, wedged between his body and the seatback.

"Or that. Those kinds of problems," (she can still remember the way his voice had rumbled through his chest against her cheek) "They're all interwoven—HA, woven, get it?—interwoven time lines within a single universe."

"But, like… say we don't get somewhere in time. Or say… say I called in sick at Henrik's the day I met you. That spawns off a parallel world, doesn't it? One where we meet and one where we don't?"

"Oh, very good, Rose; yes. Well—sometimes. Ish. Not every event, but some. Most things, the universe can compensate around them if they get altered. But sometimes—meetings never made, children never born—they matter so much that they change everything. Big ol' parallel world. That's a causal nexus. A junction, if you will. Fork in the road."

"A road made of curtains?" she'd teased.

"Oh, right. The fabric metaphor. So you've got a rip in the fabric, or the potential for one: one wrong word in the wrong place changes an entire causal nexus. But torn curtains can be mended, as long as the damage isn't too extensive. And that's where we come in. The TARDIS is like a needle, and we pull time lines behind us like thread. We patch up the hurt."

"But if we're a needle, don't we also make more holes? Punching one through every time we make a stitch?"

He'd beamed. "Rose Tyler, have I ever told you that you're extraordinarily clever?"

She'd swallowed a smile back at him, tongue in her teeth. "You may've mentioned it, yeah."

"Anyway, you're absolutely right. Which is why travel between parallel worlds isn't possible anymore. Not with a single TARDIS, anyway. As long as we stay in this reality, we seal the breach before it can cause any damage. Thread follows needle. But when you leave a loose thread… everything unravels. Both universes break down."

"It's that simple?"

"If you're me," he'd said, expression inscrutable. "But it's much easier to talk about than it is to achieve. The math behind it all is… complex."

And then the Doctor—forced to the edge of the cushion by the constant pressure of Rose's body against his own—had fallen quite spectacularly from the sofa to the floor, which somewhat ruined the serious atmosphere.

The thing about curtains, she thinks, is that they can always be drawn back. You just have to find the edge of them, first.

(She's probably the first person in the universe to have earned a PhD without ever doing their A-levels. She tries not to think of how proud of her he'd be.)

She feels like him when she looks at Tony—imagines that this must have been how he'd seen her, once upon a time. Because Tony's so young and so bright that sometimes it's all she can do not to shield her eyes… but she reckons that her brother is quite possibly the most extraordinary little person she's ever met, and that makes it worth it.

She's a rubbish big sister, of course—misses out on the family dinners and the Sundays in the park. But she occasionally lucks into the right bedtime story on the right evening, or manages to make it to a play in which he portrays Fruit in the food pyramid, and only ever carries band-aids with cartoons on them, and somehow these small gestures make her a superhero in his eyes. (And this is the part where truly acting like the Doctor would make it easier, of course. He's been running his whole life. But she's not him; she's Rose Tyler, and establishing ties and creating family from nothing and loving are what she does best—no matter how much it will hurt to walk away later.)

Pete Dad Pete, at least, seems to get it, though she can't fathom why. Their relationship is an utter mystery to her, but for whatever reason, they just… click. No matter which universe he's from, apparently. She'd wanted, at the beginning, to hate him—for rejecting her when he should have embraced her, for saving her when she didn't want to be saved—but his quiet support and awkward companionship can be a welcome relief from Tony's worship, Jackie's worry and Mickey's expectations.

It was Pete, after all, who'd silently gone upstairs halfway through her description of the Doctor's dream message only to return ten minutes later with a full suitcase of their things. It's Pete who takes a half hour out of his schedule every day to meet her in the canteen, sit with her and not-talk over a cup of coffee. It's Pete who understands why she doesn't want birthday parties, and it's Pete who makes excuses to Jackie when Rose comes 'round the house but can't stand anyone's company but her brother's. He never frets like Mum—or at least, he's much sneakier about it, if he does. Just stands in the background and waits to be needed, always catching her when she falls. (It's a bad habit of his.)

One day, she sees a blue leather jacket in a shop window while on a (forced) lunch break; she loves it on sight and buys it without a second thought. It feels like a connection and a compromise: because leather is what one wears, after all, when one has survived a war with the Daleks but lost everything. That's the rule. And blue's always been the color of getting lost and finding him again—the patchwork polo on New Earth and the t-shirt of the five and a half hour wait; a half-zipped windbreaker on Florizel Street, blue denim in 1987 and her poorly-timed Union Jack in 1941, and the stupid teal hoodie she'd worn to Canary Wharf. (And that feels very much like him, too—looking for links and patterns where they probably don't exist, as if she can create order from chaos if she wills it hard enough.)

And then the stars start going out and the Cannon starts working, and it's too miraculous a coincidence to be a good thing.

The odd thing about it is that nothing really changes. Not at first, anyway. She gets a bigger support staff and more funding, now that the Darkness is threatening everything and the Dimension Cannon means more than getting back to him. But she tries not to let it faze her. She simply works harder and sleeps never and, on occasion, gets fantastically drunk. (There are more glamorous ways to save the multiverse, of course—time was, she did it twice a week, laughing. But that was… that was far away.) And for reasons she can't articulate, seeing the whole of time and space—all that is, all that was, all that ever could be—laid out for her in lines and graphs on a computer screen is strangely anticlimactic.

(She strains to hear music that doesn't exist.)

The fabric frays, and she pulls at the threads until she finds his: winding and golden and holding the whole tapestry together. Time moves faster in this universe, she knows—so she keeps her ear pressed to the past like a glass on a wall, listening in. (It's bizarre, knowing that no matter how far into the future he jumps, he's always behind her.)

She peeks in on the alternate reality using looped video signal and stolen satellite frequencies—not enough to communicate, but enough to see and be seen. It's maddening but exhilarating: helplessly watching over him, learning to hop from the TARDIS monitor to wherever he is. From the Earth's orbit all the way to a broken down Crusader transport on a toxic planet called Midnight.

("How are we, everyone all right?"

"Earthquake, must be...")

Her breath catches in her throat, and she feels an irrational surge of jealousy as the impossible echo of his voice rings in her ears, because… because whatever trouble it is they're in—How are we, everyone all right? We must be how are we everyone all right all right all right?—they're with the Doctor, on the same bus or at least on the same planet and in the same universe, and that's more than she can say for herself.

She's always shouting his name, and he never hears her.

Meeting Donna Noble is like a breath of fresh air. Her first in years. Because if she concentrates on Donna she can convince herself that it's better to have stumbled into this wrong-right universe with the Doctor gone and the TARDIS dying than to be stuck not-knowing on the other side of the Void. Donna… Donna makes it better. Donna wants it better, and that makes it bearable.

(And Rose absolutely does not think about the real first time she met Donna—how she'd gotten it right and hadn't even realized. She'd checked, double checked, triple checked the dates, once she'd caught on. She'd probably been fifty yards away from him. Not even. And when she thinks about that—really thinks about it—she wants to hurt herself. Wants to tear out her hair and rip off her skin and bleed for being so stupid, so careless, so very close, and the darkness of her own thoughts terrify her into repression.)

Seeing Donna's it's bigger on the inside reaction releases the pressure in Rose's chest, just the slightest bit; she decides then and there that even if she never finds a way back to the Doctor herself, she'll return Donna Noble to his side even if it's the last thing she ever does. Even if what the readings say are true.

There are worse places to die than in his arms, after all.

"Were you and him…?" Donna asks, and Rose doesn't miss the way her fingers hover over the console controls, as if they recognize them.

If she had an answer, she'd give it.

Following through on the time line and sending Donna to her fate is hard, but not impossible—and anyway, she's decided not to believe in impossible things. ("You can't.") She wishes she had the words to tell Donna that she can be scared, but not to be worried; she doesn't, so she doesn't.

(And god, she's just shining—there's a fire in Donna's gaze that Rose knows too well. Sarah Jane had had it, too. As had Nancy and Harriet Jones, and Tommy and Jack and Ida Scott and so many others. And maybe Rose'd had it too, once. Maybe once she'd burned brightest of all. But that was a long time ago, and the light in her eyes, she fears, has long since gone out.)

She's only ever had two words, really—so she gives those to Donna instead, and watches her slip away.

For the first time in her life, Rose Tyler picks up a gun that shoots more than nails.

Somewhere, a wolf is howling.