Disclaimer: The characters, main plot, locations etc. are not mine. This story, however, is.
Note: I'm utilizing the unexplored plotline of Inara having a terminal illness here. It's sad, I know, but my inner sick!fic junkie simply could not resist the opportunity. Enjoy!

She's cold. Colder than Midwinter on an ice-moon, and the steam rising from the marble bathtub has never looked more inviting. So she slips gently out of her robe, forcing herself not to meet the gaze of the sickly, dark-eyed creature in the tall mirror, and steps into the water's hot, welcoming cradle. Immediately it soothes her chilled skin, lapping away at her with a caress gentler than any lover's. The tension leaves her body little by little, the ice twined around her bones begins to melt, and her eyes slip closed. Finally, in this water, behind this curtain, she can relax. For the first time in what feels like an age, she can truly relax. Her palm nets a cluster of cloud-light soapsuds, and she sends them floating across the silent bathroom with a single, playful puff of breath, her mind recalling similar games with River back on the ship. The girl's too-rare laughter fills her head, and a mixed pang of homesickness and remembered happiness fills her. She sinks deeper, wetting her hair, letting the water close over her head for a moment so all she can hear is the steady beat of her heart. No, not steady. Quick, like that of a hunted deer, running and running through the woods but never quite fast enough to outrun the hunter's arrow…

Inara surfaces quickly, taking in a breath that somehow fails to satisfy her body's sudden, fierce need for air. Her chest hurts a little, in fact it did before she even got in the bath, she just hoped that the water would dull the pain a little. Apparently not. She casts the thought from her head, focusing only on the movement of her fingers through her hair, working soap through the heavy, smooth waves. The air smells of sandalwood and warmth, and she tries to concentrate on that. Her arms, bare and slick with moisture, are patterned with bruises like shadowed amethysts. Some she recognises; the little neat ones marking areas above veins, bruises of her own creation, bruises from the needle that prolongs her life a little each day. Some are strange; manifestations of the war raging away in her bloodstream. A war that she's fought to ignore and conceal for so long now. It's beginning to take a toll, and all she can think is how grateful she is that Mal isn't here to see her beginning to crumble the way she is.

She's no longer cold, she's warm. Too warm; hot, in fact, and though she tries to lose herself in the familiar routine of washing her hair, there's no denying it. Her heartbeat quickens once again, to the point where she feels it beating against her fragile ribcage, ready to burst free at any moment. Bands of suffocating pain lock around her chest, reducing her breathing to futile, pathetic gasps that she tries automatically to even out. Panicking now would be pointless, so calm down. Despite her best efforts, though, knees draw up automatically, to protect or simply to hide her, breathing quickens, the air's so hot, so hot…
Hoofbeats drawing closer and faster, she turns for a second to face her pursuer, and the simple sight of his dead-burning eyes is enough to chill her heart. She runs and runs, but she knows it will never be enough. He pulls back his bowstring; lets a single flaming arrow fly…

Maybe such a hot bath was a bad idea.

She rinses her hair and stands quickly, feeling the velvety blackness close in a little around the edges of her vision, groping desperately for the sink, something to hold her up as she recomposes herself, breathing in and out, in and out, the drawn-out sounds becoming hoarser and more ragged as the seconds drag by. The pain in her chest is back with a vengeance – the arrow meets its mark –, and she pulls a towel up to cover her lips as a fit of coughing catches her by surprise. The taste of something unfamiliar and frightening slowly creeps onto her tongue as she fights to stay breathing, to stay conscious.

"Excuse me; is everything all right in there?" Inara breaks off with a gasp, tries to draw enough breath to form a sentence. Remembers her training: You must be both strong as marble and as gentle as mist at once. Comfort and command.

"Yes," she replies, startling herself with her own strength at a time like this. "Everything's fine, thank you." The lie comes easily, undercut with a silent plea to just be left alone. Let me have this moment to myself, please. Thankfully, whoever it is behind the door doesn't see fit to pursue the matter, and departs, leaving Inara blissfully, terribly alone.

There's a little blood staining the towel where it rested against her mouth. Somehow the sight of it is enough to constrict her lungs all over again, only this time she doesn't cough. She weeps. Tears, unbidden and scalding, spring to her eyes and course silently down her cheeks. She lifts her face to look in the steam-misted mirror, rests her burning face against its cool, soothing surface. She looks like a ghost: paler than she's ever been, eyes shadowed, not with make-up this time but merely with fatigue, her cheeks sickly-flushed from the heat, and for the first time she looks at herself and realises just how plausible dying really is for her now. There's no true way of telling when; it could be months from now, could be weeks. It could even be tomorrow, for all she knows.
Blood and salt mingle on her tongue. She's dying, dying, and here's the proof, writ in clear, startling scarlet against pure, untainted white.
The fatal wound. She's pierced by the arrow, marked for death. She'll continue to run, though, weakening until she falls. She cannot stop; all she's ever done is run from this and she cannot see a way to stop.

-fin

Well, hi. This is my first Firefly fanfic, but hopefully not my last, as long as this one is accepted well. I've been working on it since yesterday afternoon, so I hope I don't disappoint. The title? Well…since you ask, it all came from a game of word association in class. We all had to think of words linked to "health", and my good friend NotCrazyJustWeird97 (if you like Supernatural, pay her a visit) suggested Pestilence. Pestilence = one of the Horsemen of the Apocalypse, so… yeah.
Thanks for reading! Please review generously, as this is my first time posting anything Whedonverse-related, and it probably sucks, so feedback would be insanely helpful.