RIFTS OF DOMINION: THE OMEGA CONVERGENCE

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The skylight exploded inward at 02:17.

Shards of reinforced glass rained down like diamonds in the blue-white glow of the arc reactors. Bucky dropped through the hole in a controlled fall, boots hitting the polished concrete with a soft thud that the music swallowed whole. Heavy bass throbbed from hidden speakers—AC/DC, something loud enough to cover a heartbeat. Stark’s heartbeat. The one the Winter Soldier had been sent to stop.

Twelve feet away, Anthony Stark stood with his back to the intrusion, shoulders hunched over a workbench littered with circuit boards and half-assembled repulsor housings. No armor. Just a black tank top clinging to sweat-damp skin, grease-streaked forearms, and the faint, trembling line of a suppressant patch visible at the back of his neck. Three days. The file had said he was pushing himself again. The file had not mentioned the scent.

It hit Bucky like a serum overdose.

Sweet. Burning. Honey and motor oil and something darker, something that made the programming in his spine crack like old ice. His left arm whirred, plates shifting, the gun already rising on autopilot. Target acquired. Eliminate. Retrieve schematics.

Tony spun.

The repulsor gauntlet was half-assembled on the bench; he snatched it up one-handed, thumbed the emergency lockdown, and the lab doors slammed shut with a hydraulic hiss. The music cut dead. Twelve feet of open floor between them—workbenches, stools, a rolling cart of tools, the low hum of the arc reactor in Tony’s chest the only sound left.

Tony’s eyes were wide, pupils blown. Heat-sick. The suppressant patch was failing; the scent poured off him in waves now, thick enough to taste. His chest heaved under the thin tank top—breasts full, heavy, nipples peaked and dark against the fabric, the unmistakable swell of an Omega deep in an unsuppressed cycle. No one outside the inner circle knew. The world saw Iron Man. The world saw Alpha.

Bucky saw mate.

The mark on his left arm—black since 1943, dead ink under the tac sleeve—ignited. Gold flared so bright it seared through the fabric, a brand against his skin. The gun wavered.

Tony threw the gauntlet.

It clipped Bucky’s shoulder plate, spun off, clattered across the floor. Bucky lunged.

They crashed together in a tangle of metal and flesh. Tony fought like a cornered animal—elbow to the jaw, knee to the groin, teeth bared. Bucky took it all. The programming screamed finish the mission. The bond screamed mine. He got Tony’s wrist pinned above his head against the workbench, metal fingers denting the steel edge. Tony’s free hand clawed at the tac vest, nails raking skin.

“Get off me—” Tony snarled, voice cracking high, breath hot against Bucky’s throat.

The scent slammed into Bucky again. Heat-slick, desperate, begging. His knot throbbed in his pants, painful, already swelling. The conditioning fractured wider—hairline cracks spiderwebbing into canyons. He dropped the gun. It skittered under the bench.

Tony’s hips jerked up involuntarily, grinding against the hard line of Bucky’s thigh. A broken whine tore out of him. “Fuck—fuck, what are you—”

Bucky’s mouth found the gland at Tony’s throat before he could stop himself. He bit down—not hard enough to break skin, not yet—just enough to taste salt and honey and terror-sweet Omega need. Tony’s whole body arched, breasts pressing soft and heavy against Bucky’s chest plate. The tank top rode up; Bucky’s metal hand slid under it, cupping one breast, thumb brushing the swollen nipple. Tony gasped, thighs parting wider.

“Alpha—” The word slipped out, involuntary, wrecked.

Bucky’s control snapped.

He tore the tank top down the front. Tony’s breasts spilled free—full, sensitive, already leaking a thin trail of slick milk-scent from the heat. Bucky ducked his head and licked, sucking one nipple into his mouth while his flesh hand shoved Tony’s sweatpants down. No underwear. Tony was soaked, thighs shiny, hole clenching around nothing. The scent of it—ripe, fertile, ready—made Bucky’s knot pulse harder.

Tony’s hands fumbled at Bucky’s belt, frantic. “I don’t even know your name—Jesus Christ, just—”

Bucky growled against his breast, teeth grazing. “Don’t need one.”

He shoved two fingers into Tony’s dripping heat without warning. Tony keened, head thunking back against the workbench, legs wrapping around Bucky’s waist. The stretch was obscene, wet sounds loud in the quiet lab. Bucky scissored, curled, found the spot that made Tony’s walls flutter and his breasts bounce with every gasp.

“Gonna fill you,” Bucky rasped, voice like gravel dragged over glass. “Gonna knot you so deep you’ll feel me for days. Make you swell up pretty, Omega. Make you a mother.”

Tony’s eyes flew open—gold-flecked, pupils blown wide. His own left arm, hidden until now, flared gold in answer, three marks burning bright. The bond snapped into place like a circuit closing. Tony came hard around Bucky’s fingers, slick gushing down his wrist, a broken sob tearing from his throat.

Bucky pulled his fingers free, shoved his pants down just enough. His cock sprang out—thick, veined, knot already inflating at the base. He lined up and thrust in with one brutal snap of his hips.

Tony screamed.

The stretch burned, perfect, too much and exactly right. Bucky fucked him in short, punishing strokes, metal hand braced beside Tony’s head, flesh hand gripping his hip hard enough to bruise. The workbench creaked. Tools scattered. Tony’s breasts bounced with every thrust, nipples wet from Bucky’s mouth.

“Mine,” Bucky growled against his throat. “My Omega. My mate.”

Tony clawed at his back, legs locked tight. “Yours—fuck, yours, don’t stop—”

Bucky’s knot caught on the rim. He shoved deeper, forcing it inside. The swell locked them together with a wet pop. Tony’s eyes rolled back, another orgasm crashing through him, walls milking the knot in rhythmic pulses. Bucky came with a guttural groan, flooding him—thick, hot, endless. The bond flared brighter, gold light pulsing between their joined arms.

They stayed locked like that, panting, sweat-slick, Tony’s breasts heaving against Bucky’s chest. Bucky’s mouth found his again—messy, desperate, tasting heat and surrender.

Tony passed out first, head lolling, body limp and claimed.

Bucky waited until the knot went down. Then he pulled out slowly, cum and slick dripping down Tony’s thighs, pooling on the workbench. He tucked himself away, zipped up, stared at the gold mark still glowing on his arm.

He left the way he came—through the shattered skylight, silent as death.

Tony woke alone at dawn.

The lab smelled like sex and heat and gun oil. His hole ached, thighs sticky, breasts tender and bruised. Cum leaked out of him in slow pulses, cooling on the metal surface beneath him. He sat up, wincing, and pressed a hand to his left arm.

All three marks burned gold.

One of them—new, brighter than the others—throbbed in time with his heartbeat.

He stared at it for a long, long time.

Somewhere in the city, the Winter Soldier filed a false report and wondered why his hands wouldn’t stop shaking.

The fracture had begun.