Note: Because, honestly now. Biology, people.

PS: Is it wrong that this is literally the second fic idea I had after reading Leviathan? I mean, what does that say about me? (Other than: I'm female - and, as always, I write slow.)

PPS: I apologize for the dreadful pun at the end... but not really. :)

.

.

.

Deryn discovers her second mistake while the Leviathan is crossing the Peloponnesian peninsula.

Her first mistake, of course, was bringing Alek aboard – or more accurately, losing her barking mind and mooning over him. As if her disguise isn't thin enough already! And him the heir to an empire, and thinking she's a boy, to boot. Even if she reveals her secret, it's all impossible, and she's firmly told herself that.

She's also sworn that she'll stay away from him as much as she can, which ought to be easy, considering how much work she has to do on the airship (double than most, thanks to Dr. Barlow). But somehow, in her bits and pieces of free time, she always finds herself right there beside him. Mooning. Like the soft-headed fool of a girl she really is.

That, then, was her first mistake. Her second is even worse, and it's another thing she never considered when she hatched her mad plan to sneak into the Air Service.

She wakes up in her cabin, guts twisting and clenching in knifelike bursts, and thinks, Oh no.

She knows this feeling. She doesn't get it often – and never as bad as her mother, who suffers terribly, like clockwork: headaches, backaches, cramps that drive her to bed – but she knows this feeling.

She stuffs the corner of her blanket into her mouth so she won't scream in frustration at her own stupidity. Then she gets herself up and dressed, even though she's not scheduled to be anywhere for hours yet.

Daft. That's the only word for it. She's absolutely barking daft.

Nine months out of ten her only proof of womanhood is a few small spots in her knickers, and indeed she didn't even notice the last time at all. But now biology is having a laugh at her, and, she realizes (as she inhales sharply on a particularly nasty spasm), it's laughing hard.

She stands for a moment in her cabin, a hand pressing down on her twisting innards, and thinks about where she needs to go. Of course she doesn't have the necessaries, and the ship's surgeon is unlikely to stock them, either. Dr. Barlow might – but once the theft is found out (and it will be, and quickly; the lady boffin is that annoying), it'd be tantamount to planting a flag on top of the Leviathan's spine, proclaiming, Hey, all you lot! There's a girl hiding on board!

So Dr. Barlow is out. Deryn looks about the cabin. She doesn't have spare clothes she can tear apart… someone's bound to notice if her washtowel and blanket are suddenly missing bits… what she needs is a source of linens whose disappearance can't be traced to her.

Deryn sorts through the other possibilities and hits on one she doesn't much like, but is feasible at least. It also offers the smallest chance of getting her bum tossed off the ship.

She exits her cabin and makes her way to Newkirk's. No one notices a middy running about, even at an odd hour like this, and she sneaks in without any trouble. Filching the wadded-up blanket from beneath his head without waking him is a wee bit more difficult, but it's nothing she can't manage. All she has to do is ease it out, slowly and steadily…

Her innards tie themselves into a sharp knot, and she pulls harder than she meant to. The blanket pops free and Newkirk's head thumps down. He makes a sudden snork noise.

She holds her breath. She might be able to pass this off as a prank, but she'd rather not.

Newkirk rolls over without waking. Deryn quickly folds up the blanket small as she can and hopes she looks inconspicuous as she slips out of Newkirk's cabin and heads back to her own.

Now she can tear the cloth into strips… change them out in the darkness of the head when she goes off-watch. It won't be ideal, and she'll have to be vigilant about the mess - God forbid the hydrogen sniffers get too curious about her - but she can manage.

"Only a few days, aye?" she tells herself.

In front of her – too close – Alek's voice says, "Until what?"

Barking sodding spiders. Ten years off her life, and her guts choose that moment to jackknife. She fights to keep the grimace from her face and the nicked blanket behind her back. Alek's clearly just come off egg duty: no grease on his hands from the engines, no other reason for him to be awake and wandering the halls.

And what's your reason? her mind prompts. She shushes the thought, hoping he won't ask. "U-until Constantinople," she stammers out. Clears her throat. Smiles at him - cocky and swaggering. Hopes the smile hides her discomfort. Wishes he would get out of the way. Wishes the slow painful grind of her organs and muscles would bugger off for two minutes so she can think.

He nods. Yawns – covers his mouth politely, of course. Then frowns. "You're not standing watch this late, are you?"

Blisters.

"No," she says. Inspiration strikes – and it's only half a lie: "On my way back from the head." She ought to say goodnight and clear out, but daft mooning girl that she is, now that she's talking to him, she can't bring herself to stop. "How's the egg room?"

"Warm," he says, wiping at his forehead. He's sheened with sweat, which helps her state of mind not at all. "And dull. I think I prefer the engines."

"I could always sneak in, keep you company," she suggests. It makes her pulse thrum just thinking about it: a warm, dark room, only the two of them for hours on end... All the same, it's probably the worst idea she's had since she thought she could join the Air Service without planning for her -

"No," Alek says, shaking his head in what seems to be regret. "I wouldn't want you to get in trouble with Dr. Barlow."

"Aye," she says. "Any more trouble, you mean. She's a barking menace."

He grins at that, and her heart twists sharper than anything her lower organs might be doing. Daft, she tells herself, and discreetly takes a fresh grip on the blanket behind her back.

"Well, in any case," he says, "good night, Dylan."

"Good night," she says, and has to half-turn to let them pass each other. Luckily she remembers to keep the blanket out of sight. He puts a hand on her shoulder as he goes. Friendly. Comradely. The sort of thing a brother-in-arms might do without second thought or a whisper of ill intent.

The touch burns clean through her clothes and skin, down to her very bones.

She escapes back to her cabin and lets the blanket drop to the floor, the better to press her hands to her aching guts instead of to her shoulder. She can still feel where his fingers pressed. Five separate brands, and wouldn't she have liked more. She pushes out a breath and closes her eyes.

Back home, one of her mother's favorite (and barking silliest) objections had been that Deryn would forget herself – would become more like a boy than not, never fit for a woman's role again. As if a pair of middy's trousers could scramble her attic that badly!

She wishes her mother were here, now, if only to see that worry laid safely to rest.

Should she ever forget, her body seems intent on doing a bloody good job of reminding her.