Sam shouldn't have gone. Of course there was no choice but to let him be the one to go. Not the first time she's wished she was born a guy. A submarine in the forties full of male soldiers—no way she'd be able to sneak around, find what needed to be found. Of course, his stupid hair would make him stick out like a sore thumb, too, so technically—but he'd only given her that so-patient look, waiting for her to come to the obvious conclusion. For all the arguments to the contrary over the years, she isn't actually stupid.

They'd hugged. Nothing else, not with Castiel right there watching, waiting almost impatient, and he'd wrapped careful arms around her shoulders and pressed his lips down against the top of her head. She can bring to mind exactly how he smelled, right in the center of his chest. The shirt he'd worn for two days, the faintest trace of rain-fresh deodorant but also the smell of his skin. Salt. She'd said told you you should get a haircut, and he'd huffed and said, yeah, and then kissed her hair brief and easy, and stepped back to where Cas was waiting with that hard strange light in his eyes. Getting ready to jump. See you soon, Sam said, and Cas clamped a hand on his shoulder and then—

She blinks hard at the book. It's gone blurry. Her thumb hurts, and she sucks it clean of the blood and then wipes her hands hard over her face, pissed at herself—there's work to do, there's no time for this shit—and on the next page, there it is. A spell.

"Can you do it?" she says, dumping the book in front of Cas. "It calls for the power of an archangel, but—"

Cas looks it over. Irritated at first—he has been since he came back sogged out from the ocean, which Deanna did find entertaining until she realized what it meant and bloomed into full-on panic—but then considering. "It can't hurt to try," Castiel says.

Her gut's one hard furious clench. She thought he'd say something sadsacky and Cas-like, something about his powers being fragile. "I don't know how much time he has," Deanna says. Cas ignores her, looking at the ingredients. "The whole time travel thing—do you know how long we have, until the sub goes down?"

"We have time," Castiel says, barely looking at her, and she—how does he know? How can he possibly?

The majority of the ingredients are simple if gross, fetched from the catalog in one of the archive rooms. She washes her face in cold water in the WC and puts her hair up in a half-bun and looks at herself in the mirror. Her eyelashes dark spikes like she's been crying. Her lower lip so bitten and chapped she might as well be a kid again. When she remembers telling Sam, who kept chewing his lip, hey, quit it, use Blistex like a normal person, and had tugged his lip out of his mouth so many times when he was fourteen that he'd bitten her thumb once in pure bitchy retaliation. He'd stopped, though. All that work to get him to grow up and she couldn't, couldn't. Wouldn't.

In the library Cas is working, steady. Willing to try, no matter what. No matter what else has happened between them she loves him a little, for that. Only—

"Cas," she says, helpless. He dumps vervain into the steel bowl, ignoring her. "You're not strong enough. It isn't going to work."

"Deanna," he says, rough, and pauses. He picks up the butcher knife, dragging the preserved brain closer. "Have faith."

Where has he been. As though there were any point in having faith in anything but—Sam, and sometimes, on occasion, what Sam and her could do, together, and when all else failed what their friends could manage. She presses her fingertips to her eyesockets, pressing hard just under the brow bone, and she wants—more almost than anything she wants—to go back. When their problems were easier. Just a quick apocalypse or two. Sam at her side, the two of them turning to people who knew better for help—like standing in Bobby's house, getting easy answers. Getting an eyeroll and getting called stupid, but the answers came anyway, easy-peasy.

Her eyes open. Bobby.

"Wait," she says. Cas sighs. He drops the mangled flesh into the bowl. "Wait, you—we can power you up."

"How," he says.

"Use me." Cas pauses, still holding the knife. Deanna drags in air, certain. "You touched Bobby's soul, way back then, to get me and Sammy back from the past. Use me, take—whatever you need. However you gotta power up, so you can do that spell and you can get Sam back. You can do that. Can't you?"

"I… can," Castiel says, looking down at the bowl of reagents. "But I'm sure I don't need to, Deanna—"

"You can't be sure," Deanna says, quick. She comes close, sets her hand on his sleeve. "Cas, please."

Later she'll know it all went wrong—there. Right then.

Cas laughs. He never, ever laughs.

Deanna steps back. Instinct, inbuilt from age four. "What?"

"It's so strange," Castiel says. He turns, leaning his hip against the table. Weird and casual. "I'm working so hard to get Sammy back, and I'm letting you boss me around like—what, like you're interesting? You've got the connection to Amara but there's nothing about you that's ever, ever mattered to me. Isn't that funny."

His voice odd, high. Deanna takes another step back and runs into the other table. She grips the edge of it with one hand.

Castiel drops the knife onto his table and then he's—there, crowded up against her, his hands hard on her wrists. Bruising, shocking strength. She doesn’t breathe, looking up into his eyes. Unfamiliar blue.

"I always focused on Sam, you know," Castiel says. He smiles down at her, shrugs. "Girl that got away. Just hated him to bits. But you, you were always just the irritating little gravel in my shoe. Little bitch that Sam kept pining after, making him say no to everything I wanted to do. Even when I finally got in there, it was you that caused all the problems. What was it he saw in you? I never could figure it out. When, to me, you're just some stupid slut who never served her purpose. My brother never even got to take you for a ride, so what is the point of you?"

Her tongue, caught fat and shocked in her mouth, finally unfreezes. "I don't know, Lucy," she says, her voice coming from some distant place. "Must be above your pay-grade."

Lucifer smiles wider, all teeth. "Took you long enough, dummy," he says, and then backhands her so hard she falls back against the table, the legs screeching a foot backwards on the floor.

Pain's nothing—it rings in her skull, blood sluicing down from her nose, but so what—and she knows, knows, there's an angel blade on the bookshelf under the scimitar and there's another on the bar, by the crystal decanter she hasn't refilled in too long—and even if they won't work on Lucifer, at least it'll give her time—and all that goes through her brain in quick flipbook succession, knowing how to roll off the table and lunge for the bar and grab it and spin and stab him in the chest, in the fucking brain if she has to, no matter whose body he's in—but. This isn't Cas, this is an archangel, and he knocks her back to tabletop in an instant, crushing her down into the wood, not letting up. She blinks hard, tears smarting, and Lucifer arranges Cas's face into a little playact of pity, looking down at her.

"Aw, sweetheart. Feeling tough?" he says.

She lets her head thunk back onto the table. Rage ripples down through her throat and lungs and gut, chased with a liquid shot of fear. She wants the mark back on her arm. How she could tear into him, with the blade back in her hand. No matter the consequences that'd follow.

Lucifer looks all over her face, clearly entertained. "Well, that is kinda fun," he says. He transfers her wrists to one hand, squeezing so hard the bones feel like they're going to snap any second, and flicks her hair back away from her face. Smiles, softer. More awful. "You know, Cas said yes to this? He knew I was your only shot at fighting back Amara. First decision he made that wasn't grade-A idiot. But you know that wasn't the only reason. Don't you?"

Deanna breathes shallowly. The cage. Sam stuck in there, all her terror proved true, and when she broke in Lucifer beating them both bloody, her bones shuddering and Sam nearly gone and Cas shoving Lucifer away from them, from her, and—she can't—she was holding Sam, curled over him like she could protect him from what was coming, and Cas said—Cas—

He drags cool fingertips down her cheek, denting the skin. Down her throat, hard enough it hurts. "All those dumb protective urges," Lucifer says. Cas's fingers on her collarbone, and then dragging at the collar of her henley. Revealing the edge of her bra. Her heart thuds thick and slow and calm, a vast coiled beast under her skin. Lucifer's lips twitch. "All that envy. What he'll never get. And he just wants to protect you, anyway, you know that? You and Sammy. He knows. You know that, right? About you and your brother."

"Don't know what you're talking about," Deanna says. Wishes, immediately, that she hadn't. Another stupid instinct from all those years in the dark.

"Honey, you're dumb but you ain't that dumb," Lucifer says. His hand drags down, glancing over one breast and then down to her stomach. It sucks in without her say-so. "So," he says, soft. "I'll get your brother back, so I can take the Hand of God out of his big mitts. Then I'll gut him, because I am so, so tired of that stupid hangdog face of his. And I'll keep you safe and sound in my palace, a caged kitty while we work out how to take out my bitch of an aunt. But I think, first, it's only fair to give Cas a little treat, for the favor he's done for me—letting me free to take out Mork and Mindy, once and for all." He drags her hips to the edge of the table in a hard cruel haul, and smiles at her. "Mindy was kinda hot, don't you think?"

He flips her onto her stomach. Maybe he thinks that's more humiliating. She breathes slow. Not like it's the first time. Her belt snaps. Her jeans and panties hauled down to her knees. She braces her boots on the floorboards. Buzz of a zip. "Wow, not the most embarrassing vessel in the world," Lucifer says. She wants to say, Cas. Cas, stop. It's me. Cas, you can stop, it's me, please, don't let him, don't let him do it, you don't want to hurt me, Cas, can't you—can't you take control, take some goddamn responsibility, Cas, please—except there's no point in saying anything like that because if Cas were going to stop it he would have stopped it, already, and while she's thinking that his cock blunts stupid up against her, already hard, and she opens her eyes wide and sees every fleck and color of the woodgrain and then it's shoved inside. Thick. Not the thickest or biggest but she's dry and it hurts. Of course it's meant to.

She grips the edge of the table, takes it. Her hipbones grind into the wood. "Don't be afraid to make some noise," Lucifer says. He grabs her hair, pulling her face away from the safe shadow of the table, hauling her back onto Cas's dick. "We gotta make a nice highlight reel for Castiel, don't we?"

Like he's taking a walk in the park. She braces, tilts her hips so it hurts less. Because her head's been pulled up she keeps her eyes fixed on the telescope, at the far end of the library, and lets the room bob dizzily between each pummeling thrust. Her toes curl, scrunched inside her boots. Her heart a distant, steady drum.

"You're good at this, huh?" Lucifer says. He's not. His hips move like a piston but there's no imagination, either to make it hurt more or to humiliate her by making it good. Never was human and apparently never bothered to learn, either from Cas or Sam or poor doomed Nick, all those years ago. Just hard meat, cramming in where she's soft, over and over. Slick now because that's how bodies work. She doesn't know if he's ever done this before, in any body, but Cas is hairsbreadth from being a virgin so it can't take that much longer.

Sure enough: "Let's give him a show," Lucifer says, and pulls her upright by the throat. His breath coming in odd little puffs. He's not choking her but the clutch is hard enough to make her dizzy. She squeezes her eyes closed and focuses: the pole slotting in and in and in, the grip around her right wrist, the bruises throbbing up on the bend of her hips and now maybe on her thighs where she's getting crushed against the table. His chin over her shoulder, prickly stubble against the side of her neck, his voice soft while he says, "We better show Sam, too, before I kill him. Make sure he really sees. Big sister, dripping. Just like he used to, you know? Back then, when we were roomies."

She makes a sound. Not meaning to but the air chokes in her throat. He squeezes hard, laughs high and goofy.

"You're all so easy," Lucifer says, laughing, and then he pulls her in tight and pushes her own hand over her crotch and says, "Feel that," while he jerks inside, coming. She can't, other than the thickness. It should be—boiling hot, like the demons used to be, but then again he's an angel. Despite everything.

When he pulls out there's a sting. He pushes her hand down further, cups against the loose-wet gap, and she feels that first trickle, dripping. Thick.

"Too bad Michael never got to try you out," Lucifer says, soft against her ear. She opens her eyes. The library, the telescope. A little smoochy kiss against her neck. "Would've been fun to break you both in. Oh, well."

He shoves her. Deanna catches herself against the table.

"Ooh, stay just like that. Be right back, lickety-split."

A flutter, like wings. How didn't they notice that before?

She pulls her hand out from between her legs. Sticky. No red. She's surprised, considering, but then Jimmy Novak's dick wasn't all that big. Her breath and heart and mind are still slow and calm as a hibernating snake. In her pocket, a knife. She drags her jeans mostly up, folds her fingers around the silver handle. Angels and blood. Her thumbnail stings, where she tore it.

The wingbeats come again and there's Sam, in an old-time sailor uniform and his face pale and his eyes going right to Deanna, ignoring the danger at his left side.