NOTE: This fic contains Alpha/Beta/Omega dynamics. This includes mpreg, self-lubrication, and knotting. If you're not into that kinky shit, please don't read this. You will be thoroughly weirded out.

Characters: Endverse Cas, Endverse Dean, Endverse Chuck, Endverse Risa, Endverse Jane, 2009 Dean

Pairing: Endverse Cas/Endverse Dean

Tags: ABO, Endverse (referring to the alternate universe in season 5 episode 4, "The End"), miscarriage, top Dean, bottom Cas, drug use, psychosis, self-lubrication, knotting, mating bond, claiming bites

"Dean." Castiel groans out his mate's name, clenching around him as he bounces in the water, the smell of chlorine mingling with the scent of slick and arousal. Small, warm waves lap at Dean's neck, adding to the heat he feels from being inside Cas. The omega is breathing heavily, probably due to the temperature of the hot tub and the exertion it's taking him to ride Dean as hard as he is.

"Dean."

He sounds different now, desperate, and now Dean smells a faint hint of something else. Distress? He grabs his mate's hips, slowing his movement. He needs to figure out what's wrong.

"Dean!"

The alpha jerks upright in alertness. He's not in a hot tub at a luxurious resort. He's in bed, in his and Cas' cabin, in the middle of the goddamn apocalypse, and the weight of that hits him hard every single time he wakes up from a fantasy. It's worse this time, though, because all he can smell of their "home" is Castiel's fear.

"Something's wrong." Cas sounds terrified, and Dean's eyes don't need to adjust to the darkness to see why. There's blue light seeping out from beneath his mates skin. The kind of light that angels give off when they're dying. Horror claws at Dean's chest and the only thing that's stopping him from going into full-on cardiac arrest is the fact that the light is only coming from his abdomen.

"What the fuck is going on?" Dean asks, trying and failing to remain collected for Castiel's sake.

"I don't know, Dean. It hurts."

Stay calm. Stay calm.

"Stay calm, Cas."

Rain pounds at the windows and thunder rumbles nearby, adding to the grim atmosphere in the room. A flash of lightening illuminates the cabin, and when it's gone, so is the glowing of the omega's stomach. Cas' eyes flutter closed, and Dean has never felt so terrified in his life. His fingers fly to Cas' throat, and thank God, there's a pulse, quick but steady.

Dean shakes him roughly. "Cas?"

His mate's eyes open, his gaze unfocused.

"Look at me, baby." Once Castiel does, Dean pulls the omega up against his side, wrapping a strong arm around his waist. "I'm gonna get you to the med cabin, wake up Jane, and get you fixed up. You're gonna be fine," the alpha says, unsure of his own words.

The two of them are in only their boxers, and the storm has brought with it a cold front, so Dean leaves Cas swaying on the bed to grab him a jacket, not bothering to grab himself one because timing is crucial right now.

Dean is just slipping the coat over his mate's shoulders when their bedroom door swings open. It's Chuck, eyes wide and hair wet and flattened down against his head.

"He's okay," the prophet says hurriedly.

"How the hell do you know?" Dean snaps, and Chuck flinches.

"I had a vision."

Which is weird and concerning; he hasn't had one of those since the angels left.

Dean lifts Cas off the bed, taking most of his weight.

"Then what the fuck is happening?"

Chuck takes a deep breath, and the Dean smells blood.

"Dean," Castiel says shakily, gripping Dean's shoulder tightly.

"Cas, what's wrong? Where are you bleeding?"

The prophet looks down and when Dean follows his gaze he sees rivulets of blood trickling down the inside of his mate's thighs. The smell of Castiel's panic is clouding his senses, and he just barely catches the word "miscarriage," coming from Chuck.

Cas isn't dying, he losing a baby.

"He was glowing, why was he glowing?" Dean demands, and then he realizes. It wasn't the omega who was lighting up, it was the fetus. "Chuck, did we... did we make a nephilim?"

Castiel falls.