Note: Title taken from a quote attributed to Hippocrates:

"Healing is a matter of time, but it is sometimes also a matter of opportunity."

This is the end.

That's what he thinks, hands shaking, mouth dry, stomach twisted with nausea and dread. This is the end, here, in the darkness, the cobblestones digging into his knees, the cloying stench of the filthy alleyway filling his nose.

This is the end. Gaby, bleeding out in his arms.

Her blood coats his hands, slick and dark, seeping sluggishly between his fingers from the hole just below her breastbone. She doesn't move, doesn't make a sound, and he fears that it is already too late. Something in his chest gapes open, a chasm of terror that he has not felt since the day they dragged his father away, and he bows his head over the motionless body in his arms and tries to breathe.

He does not know what he will do if she dies.

It begins five hours earlier, at a stained and pitted table, in a hotel room that overlooks a dingy back alley, on the edge of one of the seedier areas of Moers.

There are maps and plans and diagrams spread out across the table, an abandoned coffee cup acting as paperweight. Gaby is perched in one of the two rickety chairs, feet drawn up under her, fingers running over the blue-inked lines as her lips move soundlessly. She does this every time, runs through every possible escape route and exit strategy in her head before an op, charts it with her fingers as if she can take apart the diagram and put it back together like one of her beloved engines.

Illya watches her covertly, from the corners of his eyes, as he cleans and re-cleans and obsessively checks every weapon in their small cache. He has them all spread out on the end of the single double bed—not much room, but he's making it work. They each have their own methods of preparing for a mission, their own ways of calming themselves enough to harness the adrenaline, force it down into laser-sharp focus and steady hands.

He is having trouble controlling his nerves tonight, though, and he doesn't know why. Something about the whole setup seems off by just a hair, like a sight that won't quite focus, and it has him edgy and preoccupied. He has cleaned the barrel of Gaby's Browning three times now, and he hasn't paid proper attention to it once. Finally he gives up, sets the gun down and looks over at her.

"Surely you have it memorized now, da?" he says, and doesn't bother to hide the edge in his voice. She flicks a glance up at him, and he can tell just from the thin line of her lips that she's irritated with him.

"I will have them memorized, if you will stop talking," she mutters, and shifts the coffee cup to one side to pull out yet another diagram. He grits his teeth.

"We do not have all night," he reminds her. She shoves her bangs out of the way roughly and makes a sharp motion with her hand in his general direction, as if waving away a large and annoying insect.

"I know this," she says distantly, without looking at him. Then, after a moment— "Verdammt, Illya, we can't even get into the factory until after the shift change at 11:00. What is the rush, hmm?"

He shakes his head, trying to shift away the gnawing sense of something about to go wrong, and gets up to stand at the window, looking out at the dank, narrow passage below.

"I am ready to go," he says finally. It's as close as he will get to admitting that he's on edge, nerves tightened to the breaking point, and she lifts her head from her diagrams to lay a small hand on his sleeve. He starts a little at the touch, his skin humming as it always does when her hands are on him.

"Calm down," she tells him bluntly, but her fingers are gentle when they stroke over the dark fabric. "It's nothing we haven't done before."

"I know," he says, and moves away before he does something foolish. They have worked together for over a year now—an entire year, three hundred and sixty-five days and change of exponential longing, and it is becoming increasingly difficult for him to bear.

He remembers learning about exponents in his mathematics courses in the state schools, remembers being fascinated by how quickly even small numbers could grow to something enormous when raised to a large enough power. It is the best way he can think of to categorize this thing that has grown up between himself and Gaby—a small something, a flash of attraction in a dress shop, a dance turned wrestling match in a hotel room in Rome, her voice screaming his name as he tumbled down a mountainside—all of it magnified, become impossibly enormous, engulfing, when raised to the power of twelve months spent working together in incredibly close conditions. It is so huge now that he cannot even think to escape it; he is simple hoping that he can learn to cope with being hopelessly in love with his partner without ever letting her know. (He is aware of the fact that he will most likely fail.)

Shaking away thoughts of love according to the rules of mathematics, he paces from the bed to the tiny bathroom and back again, stalking over the cigarette burns in the carpet, one foot placed precisely before the other. After a moment, he hears her scoff in annoyance.

"Must you do that?" comes her voice from behind him, laced with exasperation. "I am almost finished. Why don't you do something useful, finish packing up the weapons or something?"

He glares mutinously in her direction, but does what she says anyway. He is not doing either of them any good letting the nerves show like this, and he knows it.

It takes her another ten minutes before she's satisfied, and then she's rolling the plans and diagrams into neat cylinders, stacking them neatly in her briefcase before she clicks the locks closed and spins the dials that Solo had personally installed to prevent easy lock-picking.

"Ready?" she murmurs, and he nods. Forebodings or no, they have a job to do.

She goes first, briefcase strapped to her back, gloved hands clutching at the climbing rope they have anchored to the windowsill. They cannot afford to attract attention by leaving in the conventional method—best to quietly slide to the ground from their second-story window and slip into the getaway car parked conveniently below. She's poised on the edge of the sill, ready to slide down, when he holds up a hand to stop her. She looks the perfect spy, his little chop-shop girl, lithe body all in black, eyes dark and focused, but there's something missing. Gravely, he pulls a black knit cap from his back pocket and settles it over her smooth bun, tugging it down over the tips of her ears.

"What is this?" she says, puzzled and a little wary, and he lets himself just barely smile at her.

"To keep hair in place during mission," he explains, very seriously, and she rolls her eyes at him.

"Of all the things to worry about—" she begins, but he takes a gamble and shushes her with his thumb, light against her lips.

"Time to go," he tells her, and sees her lips quirk before she disappears from view.

When he follows, the heavy case containing their weapons in one hand and what little luggage they have on his back, he feels his spirits lift a little at the sight of her sitting behind the wheel of their nondescript car, the cap still firmly in place. She is ready, and he must be as well.

Perhaps the foreboding is just that—nothing more.

A/N No. 2: So...I am very much aware that I have an unfinished WIP and a series of vaguely related one-shots strung together that I really should be working on. But this idea grabbed hold and would not go away, so I've been working on it for three weeks or so. The whole thing's mostly finished, although I'm still figuring out how I want to structure the chapters and dealing with a few thematic elements. On the bright side, since it's mostly done, updates should be fairly frequent!

Please let me know what you think-it's the first time I've written anything even vaguely approximating mission fic, and I'm hoping that it works, more or less. (Although you should probably be aware of the fact that the mission aspect evaporates fairly quickly in favour of shameless hurt/comfort.)