Chapter Text
Dean always figured Castiel was a Beta.
Or, at least, he figured angels didn't have secondary genders whatsoever. After all, every single angel he encountered didn't have a scent or anything similar. Not Anna, not Gabriel, not Uriel.
Not Cas.
Cas never gave off a scent. Never reacted to Dean’s or Sam’s, not even during rut, when they were raw with instinct and forced to isolate themselves for days. He never so much as flinched at pheromones thick with rage or fear, signals sharp enough to put any Alpha on edge or make an Omega pause.
Cas remained unchanged. Steady. Impassive. Contained.
More angel than anything else. Immune, or maybe indifferent, to anything that stirred beneath their skin.
Beta. Safe. Untouchable.
That was until they made it to Grants Pants Oregon, the place where Eve was hiding out in.
Castiel flew them within seconds, just like he always did. But the moment their boots hit the ground, something was off.
Cas stumbled slightly, catching himself mid-step. Which was not common for the angel whatsoever. He had always been deliberate and precise with every movement, almost as if he had planned it centuries beforehand. Dean frowned but decided not to dwell on it.
Bobby needed to sit down with his computer, so they made their way to the first diner they saw. The diner wasn’t much to look at from outside. Flickering neon sign, tired booths visible through the front window, the kind of place Dean normally wouldn't think twice about.
But Castiel lagged a step behind.
Dean turned to toss some offhand comment toward him when he actually looked at Cas. He kept tugging at the collar like it was too tight, even though he wore it like armor most days. There was a sheen on his forehead, just enough to catch the streetlight. Dean frowned.
“You good?” he asked, trying to keep it casual.
“I’m fine,” Castiel replied, but his voice caught on the word like it didn’t want to be said.
Dean kept walking, slower now. Cas followed, but the rhythm was off. Too stiff. Too unsure.
Then he smelled it.
It was so faint he almost missed it completely, but as soon as Cas started walking beside him, he smelled it.
Pie.
Honey pie, to be precise. It smelled like heaven. Warm, rich, and unmistakably sweet. It drifted through the air like something freshly baked. The scent was comfort wrapped in sugar, but underneath that? There was a note Dean couldn’t ignore. Not just pie. Not just hunger. It was sweet in a way only an Omega could be. His mouth watered before he even realized what he was reacting to.
The most delicious Omega Scent he had ever smelt
And it came from Cas.
He blinked twice, completely confused. As he tried to approach Castiel to properly scent him, the angel took a step back.
“Dean?”
“Cas. You, uh.” He stopped, embarrassed. He had never tried to scent Castiel before, the same way he never tried to scent a Beta. It was stupid, almost offensive. “You put on perfume?” Cas tilted his head in response.
“Why would I do such a thing?”
“Don’t know, man. You smell weird". So good it’s making me dizzy. Dean swallowed hard.
You smell so fucking good. I need to scent you or I’m going to lose my damn mind.
“Will that hinder the mission in any way?”
“Well, no, I just thought-”
“Then let's not waste any more time, Dean.” Cas said as he turned around and walked quickly to the diner’s door. Dean followed on instinct, Alpha courtesy mode flipping on like muscle memory. He picked up his pace, reached the door first, and held it open without thinking.
What is wrong with me? This is Cas, not an Omega. My wires must be crossed.
Castiel blinked and frowned, but he still nodded towards Dean and entered the diner before him. They all slid into a booth near the back. Cas sank into one side, looking vaguely uncomfortable, as he tried to find a more comfortable position on the hard seat. It was weird to see the angel this uncomfortable.
Sam started to slide in beside him, but Dean moved faster. With a muttered “I got it,” Dean shouldered past his brother and dropped into the seat next to Cas, leaving Sam blinking once before shrugging and taking the opposite bench next to Bobby. Something low in his chest uncoiled. He could feel it, even if he didn’t mean to, his scent pushing forward, not aggressive but firm, territorial. The invisible perimeter of a line drawn by instinct.
Cas gave no outward reaction, but he sat a little straighter.
Dean breathed in slowly.
“Dude.” Sam said and frowned at Dean, “Can’t you, like, control your pheromones for a bit? You are going to draw attention to us. Eve could be anywhere.”
“Sorry” Dean murmured, eyeing Castiel slightly. The scent coming from him was still very faint, but it lingered in the air enough to keep Dean’s alpha on guard.
As they discussed the plan to track down Eve, Dean stayed tense, scanning their surroundings carefully. Anytime an Alpha scent so much as brushed by, his posture tightened, eyes darting. Then Castiel spoke up, calm and clipped as always.
“I’ll search the town. Give me a moment."
Dean didn’t like that. The thought of Cas just taking off without him scratched at something raw. But he swallowed it down. This was a mission. He wasn’t about to let his alpha instincts screw with the job. Which was ridiculous. Cas couldn’t be an Omega. He was Cas .
Still, when Dean nodded for him to go, Cas didn’t move. And suddenly Dean wasn’t sure which part of this was the most unsettling: that Cas wasn’t flying off like usual or that he was glad he hadn't
“Cas?” Sam asked. Dean noticed a single drop of sweat traveling down the angel’s face.
“I’m still here” He seemed confused by his own statement.
“Yeah you don't have to wait on us” Dean added, still hoping deep down the angel wouldn't leave his side. Castiel closed his eyes to seemingly concentrate but still remained in place. “Now it just looks like you are pooping." Dean joked.
“Something is wrong,” Cas murmured.
There it was again. Omega scent.
Worried Omega.
It hit like a punch to the chest. Castiel lifted his gaze, voice barely a thread.
“I’m blocked.” He lifted his head to look at Dean. “I'm powerless". Dean blinked twice at the statement. “Something in this town is affecting me. I suppose it is Eve.”
“We gotta find this bitch quickly." Dean said, and Sam frowned at the sudden smell of protective alpha.
“I think I found something.” Said Bobby. He began to explain how a doctor reported an illness he couldn't identify, but Dean only half-registered the words. Castiel was standing too close. Too quiet. His scent was sharp with unease, tinged with something almost frightened. Dean’s jaw tightened. It was getting harder to focus on the case when every nerve in his body was tuned to the angel’s unraveling calm.
“Okay.” Dean simply stated when Bobby was done with his explanation. “Me and Cas are going to check out that doctor’s office.” He patted the angel twice on the shoulder. “C’mon buddy, walking around a little won't hurt you. Let's put those wings to rest.” Castiel frowned in response, but he still nodded and followed Dean outside the diner.
As they made their way to the doctor’s office, Castiel suddenly stopped Dean.
“I should leave,” he added, stiff and clipped. “I’m compromising the mission.”
Dean’s brows furrowed. “What the hell are you talking about?”
“I…” Cas hesitated. His hands curled slightly on his trenchcoat like he needed something to hold onto. “When angels are in vessels, we don’t… present.”
“As in secondary gender stuff?” Dean asked, understanding and softness lingering in his voice. Embarrassed omega scent hit Dean’s nose as Castiel nodded
“The grace, the power, it overrides everything. Secondary characteristics don't manifest. There is no need for it.” They all stared at Castiel in silence.
He swallowed. His voice wavered on the next words.
“But now… I can’t suppress it. The more time passes, the more it surfaces. And I… I don’t know how to manage it.”
Dean stared, words caught somewhere in his throat.
“I’m presenting,” Cas said, softer this time, like the word cost him something. “As an Omega.” Dean was holding his breath. “And I can’t predict how long until my body follows through. If I go into heat while we’re tracking Eve, while you’re exposed to me…” he glanced at Dean then, with something close to regret, “I could jeopardize everything.”
There was fear in his voice now. Fear and shame.
Dean leaned closer, his voice low, steady, and anchoring.
“Cas. You are not a liability.” Castiel seemed so damn shocked Dean felt like crying.
“But you don't understand,” Cas said, voice low. “My status could compromise everything. I’m already…off. Erratic. And if she can smell-”
“Dude,” Dean cut in, sharper than he meant, but the panic in Cas's eyes made him soften immediately. “Bobby is the only lucky bastard here, being a Beta and all that.”
Cas blinked at him.
Dean exhaled and kept going. “You think Alphas don’t react? You ever seen me in a room with blood and pheromones and think I’m rational ? Hell no. We’re wired, man. It’s instinct, not failure.”
Castiel stared at him like he was seeing something for the first time.
“You’re still here, still trying. That doesn’t make you a liability; it makes you brave. Braver than most Alphas I know.” Castiel frowned; he seemed to be having trouble believing it. Still, he nodded.
“Thank you, Dean.” The delicious pie scent hit Dean’s nose again, and he visibly relaxed. The angel did not smell uncomfortable anymore. He smelled calm, and now the natural sweetness of Omega scent was definitely doing weird things to his Alpha’s instincts. He might become addicted to this scent if he wasn't careful.
“Yeah, whatever, man.” He looked away from the angel, trying to stop himself from catching more of that omega pie scent and getting more distracted than he already was. “Let's find this bitch.”
Oh, and find her they did.
After spending the entire day scouring the town, it turned out Eve had been hiding in plain sight the whole time. Right there in the very first diner they’d stepped into. There was no way she hadn’t seen them come and go. If she’d wanted them dead, they would’ve been. No, she had a plan.
“Okay.” Dean sighed and looked at Bobby and Cas. “Me and Sam are going in.”
“Dean-” Bobby began to talk, but Dean quickly interrupted him.
“Look, we don't get a shot off; you two better.” He said, pointing at their respective guns, full of phoenix ashes.
“That’s the plan?”
“Pretty much.” Dean loaded his gun, ready to walk in when Castiel suddenly grabbed his arm.
“Dean. Let me come with you.”
Needy omega scent, calling directly to his Alpha. Oh, Cas was using dirty tricks.
“Cas, we need backup outside, okay?”
“I can be helpful, Dean. Just because-”
“This has nothing to do with it, okay? This is the smartest way to take her ass down. We need people outside, and I trust you, Cas.” The angel sighed, but he still nodded.
“I understand, Dean.” He began to walk away, but when the clear scent of distressed and worried Omega hit the hunter’s notice, he couldn't just ignore it. Without thinking about it for more than two seconds, he pulled Cas gently but firmly toward him, guiding the angel’s face to the curve of his neck, over the scent gland nestled beneath his jaw.
“Dean? What are you doing?” Cas asked, more confused than he should. Has he never done this before? That’s insane.
“Breathe.” Dean murmured, voice low. “Just breathe.”
His own pheromones shifted, instinctively softening; warm and something steadier underneath, like sun-warmed leather. Calming. Grounding. A silent signal: It’s going to be okay.
Cas froze for a heartbeat, then inhaled. Slowly. Deeply. His shoulders eased, just barely, and Dean felt the tension bleed out of him. They stood unmoving for a couple of seconds, until they heard Bobby clearing his throat behind them.
“Ya’ done?” Bobby drawled, one brow raised in amusement.
As they turned, they found him standing there, arms crossed, while Sam just looked baffled, eyebrows halfway to his hairline. Before Sam could even get a word out, Dean brushed past them both and headed straight for the diner, jaw set and silent.
Well, it all went to shit pretty quickly. The whole fucking diner was full of Jefferson Starships, and just as the brothers were trying to escape, Eve herself stopped them. She didn’t attack. Not right away. Instead, she talked. She explained her plan in that eerie, too-smooth voice: how Crowley was still alive, how he was after the souls in Purgatory, how she needed him stopped. And then she made her offer: bring her Crowley, and she’d let them all walk out alive.
Dean didn’t even blink. “Pass.”
Eve’s smile didn’t falter. Instead, she gestured, and the back door creaked open.
Two of her creatures escorted Bobby and Castiel into the room. Bobby looked pissed. Cas looked pale, drained in a way Dean wasn’t used to seeing. Still powerless. Still grounded.
Dean’s jaw clenched. He tried to step forward instinctively, placing himself between Cas and the nearest Starship. But one of the creatures grabbed him by the shoulders to keep him in place.
Cas looked… wrong. Unsteady and flushed with something more than just exhaustion. His scent hit Dean like a freight train, thick with distress, laced with something deeper. Sweeter. Instinctual. Omega .
Dean’s breath caught. His own scent flared in response. He could feel it happening, the slow and strong smell of heat lingering in the air. Not now. Not here.
Eve tilted her head, eyes narrowing. “Oh,” she said, amused. “ That’s interesting.” She walked towards Cas. “I have never seen an Omega seraph. And I am much, much older than you. I wonder what we could do with you”
“Get away from him,” Dean growled, straining against the grip of the Starships holding him back. His muscles burned, but he didn’t stop. “I swear to God, if you touch him-”
Eve turned to him, amused. “Oh, I plan to. After I am done with you.”
And then she was in front of Dean. He barely had time to react before her hand gripped his jaw, tilting his head back. Her mouth was cold against his skin. And then she bit. Deep.
Pain flared white-hot. Dean gasped but didn’t fall. His blood burned, but not the way she expected.
Eve staggered back, hissing, her lips stained red. “What did you…?”
Dean wiped the blood from his neck, eyes dark and steady. “Phoenix ash,” he said, voice low and feral. “Hope you choke on it.” But even as Eve gasped and her body began to quake under the venom coursing through her, Dean’s attention was already sliding, dragging itself toward Castiel.
The angel was ruffled, his coat scorched and clinging. The scent of him was still wrong, something wild and electric and unmistakably omega in heat . It pulsed through the air like a siren call, distorted by pain, and Dean felt it going across his senses like claws. Every instinct in him went primal. Not because Castiel was presenting, but because he was reacting.
He needed to protect him. Cas wasn't safe here
Ferality bloomed in his chest like wildfire.
Dean took a half-step toward him, hands curling into fists at his sides, barely suppressing the snarl that caught in his throat. “Cas,” he rasped, nearly breathless.
Eve’s gaze snagged on Dean’s again, desperate now. Her body arched, smoke pouring from her mouth in thick ribbons. Her skin bubbled and cracked, vessels going black with ancient rot. With a final breath, she burst, light and ash expanding outward. The Mother of All was no more.
But there was no silence.
Above them, the starships responded, weapons priming with a bone-shaking whine. The air turned to static.
“Close your eyes!” Castiel’s voice cracked like thunder.
Dean dropped, shielding himself just as the room exploded in light.
Grace, untethered and incandescent, poured from Castiel’s body like a detonation. The starships blinked out of existence. Everything burned. When it faded, the room was leveled. Smoke clung to the walls. Blood pooled under limp, unrecognizable bodies.
Dean rose slowly, breath ragged. The scent was gone, Cas no longer radiated heat, no longer smelled like need. But the ghost of it lingered, clinging to Dean’s senses. His instincts were still on high alert, still snarling beneath his skin. He didn’t just feel feral, he was feral.
Dean took a staggering step forward. His eyes, dark and locked, were fixed on Cas, who stood at the center of the wreckage, renewed and utterly blank. Dean could smell the absence on him now. Not omega. Just emptied again.
Sam stepped forward, cautiously. “Dean? What the hell just happened-”
“Don’t,” Bobby barked, sharp and sudden, throwing an arm across Sam’s chest. “Step back, boy. Now.”
Sam blinked. “What? Why-”
“I said back,” Bobby hissed. Sam hesitated, he took a slow step back, hands raised.
Dean didn’t even notice.
He was barely breathing now. His shoulders were tense, jaw clenched, eyes wild. His body couldn’t read the lack of scent, couldn’t understand why his instincts still screamed to chase, to guard, to claim something that wasn’t there anymore.
Cas moved first.
He stepped forward slowly and raised both palms like he was approaching a wild animal.
“Dean,” he said, low and calm. “It’s me. It’s over.”
Dean flinched, something shuddering loose behind his ribs. His hands trembled. His voice was a rough rasp, breaking against clenched teeth.
“Dean, I know it is hard, but I need you to take a breath. I am okay, nothing happened. I am no longer presenting, there is no Omega in need of protection.” Cas said.
Dean shook his head, biting back something raw. “It doesn’t just go away.”
“I know.” Cas closed the distance, slow but steady, until they were almost touching, barely inches between them. And finally, Dean moved. Not an attack or a kiss. Just a collapse. He swayed forward, shoulders pressing into Cas’s chest, like his body couldn’t hold the charge anymore. Cas caught him gently, fingers threading behind his neck like he’d done it a thousand times before.
“It’ll fade,” Cas whispered. “But I’ll stay until it does.”
Behind them, Sam and Bobby stood frozen, silent. Sam’s brows furrowed in confusion. Bobby just exhaled, long and tired.
“God help me" Bobby murmured.
Dean stood slowly, chest heaving. The feral edge hadn’t left him, it couldn’t . Not yet. The phantom of that heat still clung to his senses, ghosting through his bones. Cas smelled like nothing now.
And somehow that was worse.