AN: This fic is a prequel to "The Sins of the Father" and "Reckoning" and can be read as a standalone.

This fic contains heavy themes of rape/non-con, blackmail and manipulation. All non-con happens off-screen, but the aftermath is shown. There will be much angst and hurt/comfort.

Steve doesn't have any scent when he rescues Bucky.

That is almost more jarring than the physical aspects of his transformation. He explains it on the march back from the Austrian factory and Bucky listens, his mind reeling and his bones aching from whatever Zola had done to him.

"They thought the serum would turn me into an alpha," Steve says, his mouth pulling into a sneer. "When it didn't they had to figure out what to do with their soldier omega."

"What'd they do to you?" Bucky rasps, his mind filling with horror stories from Hydra camps about dissected scent glands and needles full of untested hormones. The reality is not as dark, but it's hard to swallow.

"They kept me on house arrest until they could develop suppressants for me," Steve replies grimly, his eyes up ahead as they march through the woods. "Howard made 'em. You remember him from the science expo? He helped with the serum and took over after Erskine died and I didn't turn out right."

His mouth crooks up humourlessly. "No one can know 'Captain America' is an omega. As far as the world is concerned he's the all-american alpha."

Bucky growls low in his throat and Steve lets out a huff, giving his head a shake. "Even then they wouldn't let me into combat. I've been on the USO tour for the past few months. Performing."

Bucky glances over his tri-coloured costume, the fabric singed and full of holes thanks to their fiery escape. "That's where you get that shield?" The shield in question is now strapped onto Steve's back, the metal dented where Schmidt had punched it.

Steve nods briskly. "Yup, and this helmet." He knocks the side of his head with his knuckles and the 'helmet' lets out a hollow ting.

Bucky gapes, stopping in his tracks. "Are you crazy?!" he sputters, his alpha instincts going into a frenzy. Three and a half weeks after Azzano and his scent-patches are all but gone and he knows he spikes the air with burnt pine and smouldering moss, his natural scent bitter with stress and worry. "What'd you go and do that for?"

He can no longer smell Steve's responding emotions and the blindness throws him off-balance until he gets a read on Steve's face. It solidifies into a thundercloud, his eyes darkening.

"Your whole unit was captured," he says, his voice hard, his eyes daring him to argue back. "They told me you were dead, Buck, and they weren't going to rescue anyone till the end of the war." His lips peel up in a snarl, his pace increasing, forcing Bucky to keep up. "They were benching me just because I was an omega. If I was going to do anything with the serum, it might as well be this."

Bucky lets out a quiet breath, letting his scent back off with understanding. Tension eases out of Steve's shoulders and Bucky gives him a nudge—the same scent-marking they'd done since childhood. Bucky tries not to think too deeply about the fact that Steve's own apple and honey scent is nowhere to be found.

"What'll happen to you now?" he asks quietly, his pine-tree scent getting damper with concern. "The army doesn't look kindly on people who go AWOL."

Especially if that person is an omega, he thinks.

Steve sighs and shrugs, a stubborn look growing on his face. "Guess they'll have to decide if they want to court marshall Captain America," he says dully.

His mouth pulls up—for real this time—and he nudges Bucky back. "It'll be worth it though, if I could get you and the rest of those guys out of there."

As it turns out, rescuing 400 prisoners from a Hydra camp and procuring a sample of Hydra's creepy blue tech does wonders in gaining favour, both in the eyes of the military and the public. It helps that no one but a few people in the SSR actually know that Steve is an omega. To the rest of the world, he is the American dream.

Instead of court marshalling Steve, Command ships him off to London. Soon, Bucky finds himself in a crowded bar, watching Steve finally build something he can be proud of, now that people are willing to listen to him.

He's still the same, he thinks as he sips at his beer, watching Jones and Dernier laugh at something Steve had said. He's saying the same things, he's just finally in a body that will let him be heard.

From the table across the bar Steve gets up and orders another round for the guys. He catches Bucky's eye and Bucky expects him to come over next, but Steve's expression clouds, his head lifting to scan the crowd.

Bucky follows his gaze, trying to spot what had tipped him off. Steve had told him his senses are more powerful than before. From the look on his face it's likely his enhancements are acting up now. Although how he can hear or smell anything over the din of the crowd is beyond Bucky. He can't imagine what the bar must feel, sound, and smell like to an extra-sensitive omega.

Steve must spot what he's looking for because he pushes off from the bar, his shoulders cutting through the crowd as he marches towards the back wall. Bucky follows his path with his eyes and catches sight of what must have called to Steve.

An American alpha soldier dressed in a well-pressed uniform leans over an omega girl. His hand on the wall boxes her in, a fact he exploits as he ducks his head and crowds her backwards. Bucky can't tell what he's saying, but from the cocky tilt of his lips and the way the girl pulls her head away, he doesn't need to guess. Her shoulders are hunched, her body language clearly belaying her discomfort as Steve makes a beeline for the two.

Bucky is on his feet without conscious thought. This is not the first time he's witnessed Steve taking exception to a pushy alpha and that usually results in anything from a few bruises to a broken nose.

But that, of course, had been the old Steve. The small omega Steve who had had to growl before any alphas would even look at him.

This time Bucky watches as Steve marches confidently up to the alpha, his stance oozing authority rather than aggression. The alpha looks up as Steve clasps a hand onto his shoulder and leans in to mutter a few pointed phrases into his ear.

The alpha's face reddens with either embarrassment or anger but even then the confrontation doesn't break out into a fight. The alpha pulls away, hastily straightening his uniform to try to preserve whatever dignity he has left before shrugging off both Steve and the omega as nonchalantly as he can.

Steve steps back enough to give the girl some space but he stays until the American soldier is out of sight, the crowd swallowing him up. Steve then exchanges a few words with the girl and she nods towards a mixed pack of people a few tables away, all of them watching the interaction with tense focus.

Steve smiles and nods, sending her off to her friends before finally turning around and heading back towards Bucky's perch. Bucky sits back down and grabs his beer, saluting Steve as he comes closer.

"Evenin' Captain," he jokes, meeting his eyes over the rim of the glass. "All's well, I hope?"

Bucky can see Steve's shoulders relax and the sparkle return to his eyes as he smiles and sits down next to him. "Never better, Sergeant," he replies. "Turns out Captain America's good for something."

Bucky salutes to that with his beer, even though privately he knows that Steve Rogers is always more important than whatever it is people see in Captain America. It was Steve Rogers who went across that room, not the Captain.

He says as much when Steve asks him if he wants to join the team he is putting together. He can't read Steve's scent, but he can see the hesitance he hides behind the question. Bucky knows that Steve is worried about what Hydra had done to him in the camp, but his expression eases when Bucky accepts (following him, not Captain America), and Bucky knows that nothing Hydra could ever do would make him drop out of the fight. Not if Steve is running head first into it.

"You're keeping the suit though, right?" he teases, and Steve laughs, throwing his head back.

"You know, it's kind of growing on me," he smiles. "I think I'll go to Howard and see if he can't make it a bit more sturdy."

Bucky scoffs and rolls his eyes. Yeah, maybe he can come up with something better than a tin helmet.

oOo

Bucky is busy the day Steve goes to see Howard about his suit. Turns out being captured and then rescued from a crazy blue-powered enemy is a big deal and he and the rest of the Commandos have to sit down and write a report about it.

Bucky gives full details about his work in the factory, but leaves out most of what Zola had done to him. He may be an alpha, and therefore not as vulnerable as Steve, but he isn't about to risk getting snapped up by some crazy scientists somewhere so they can figure out what Zola had injected him with.

He has an idea what it is anyway.

He goes looking for Steve after the meeting with Howard. He knows Steve had sketched something for Howard to work on and he's curious to see how it went. Anything could be better than the tights they'd had him in before.

To his surprise, he has a hard time finding Steve. They had agreed to meet down by the water, but when he gets there, Steve is nowhere to be found. At first he thinks Steve might be running late, so he hangs around, his hands in his pockets, staring out at the Thames. It reminds him of home, the smell of algae and river water not that different from the docks.

A clock chimes in the distance and he begins to wonder where Steve could be. The wind whips at his hair as he scouts the pier. Pedestrians weave in and out of his view but Steve's new distinctive form is nowhere to be seen.

Maybe his visit to Stark is more complicated than he expected, he thinks, turning away from the water and deciding to head back to Howard's workshop. If he's lucky he'll run into Steve on the way.

He keeps his shoulders hunched, steering clear of as many pedestrians as possible. He has some suspicions about what Zola had done to him, and while his nose may not be as sensitive as Steve's, new scents and people put him on edge.

He knows he is safe in the city. There is no way Hydra could snatch him up again. But Steve had told him about the undercover agent who had killed Erskine and Bucky has to swallow down a growl and a glare whenever a stranger gets too close.

Get a grip, Barnes, he thinks as he nears the warehouse Howard is based in.

He jams his fists deeper into his pockets and tries to shake off the paranoia that clings to his skin. He has to keep it together. He can't risk getting put on stress leave or something when Steve is about to launch his campaign.

He scans the block around the warehouse and instinctively scents the air before he remembers that he can't smell Steve anymore. He swallows an irritated grumble and marches forward, scanning each of the passing civilians with a bit more hostility than necessary.

The warehouse doors are closed, the downstairs lights dim. Only a few lights in the upstairs portion remain on and Bucky frowns, slowing down. It's around supper time, so he supposes the warehouse might be closing up for the day, but that doesn't explain where Steve is.

On instinct he skirts past the entrance and heads for the alley alongside the building. The street lamps cast dark shadows in the narrow space, but he is able to make out a lone figure leaning against the wall by a doorway. A figure whose scent he can't find amid the dirt and grime of the alley.

"Steve!" he calls, and the person gives a start.

Bucky comes closer, his spirits rising. "Where'd you go?" he calls as he approaches, giving Steve a once over.

Steve is dressed in his dress uniform, his captain insignias gleaming in the pale lamplight. The uniform is the best thing Steve owns to date, but it is rumpled compared to this morning. His tie hangs loose, his shirt half untucked. The drab wool coat is wrinkled and scuffed from where he'd been leaning against the wall.

Steve's hair is tousled too, as though he'd been running his hand through it, and his face is pale, a shadow of unease under his eyes.

Bucky frowns, slowing to stop in front of him. He breathes in, but only picks up the lingering traces of Howard's workshop from Steve, wood dust and leather varnish filling his nose.

"You okay?" he asks quieter.

All that question does is make Steve shake his head and stand up fully, straightening his uniform.

"Yeah," he replies roughly, clearing his throat as he tucks in his shirt. Bucky tries to meet his eyes but Steve won't look at him, his gaze skipping sideways and never staying still. "Sorry. Things ran a little late."

Bucky flicks his eyes over Steve again, trying to figure out what's wrong. Steve is acting jumpier than usual, but his scent is frustratingly absent, making it harder to read him. He chews on the inside of his cheek, his hands clenching in his pockets. A breeze whips through the alley and Bucky sees Steve's nose wrinkle as the concerned tint of his own scent becomes more obvious.

Before Bucky can say anything Steve steps forward and bumps shoulders with him. "I'm fine," he says, ducking his chin. "I'm not helpless anymore. You don't gotta worry so much when I'm a little late."

Bucky huffs and shoves back with his shoulder. "You sure? 'Cuz I found you in an alley anyways." He swallows, unsure how to address his lingering concern. "You get Howard to look at your suit?" He nods towards the warehouse. "Looks like things are closed up."

Steve's eyes drop away from his and he pushes forward, heading out of the alley.

"Yeah," he throws back as Bucky turns to follow him. "Most people had already left. But Howard was there." His shoulders roll inwards and he tugs on the sleeves of his uniform before running a hand swiftly through his hair. "He got everything measured for the suit."

Steve's eyes are planted firmly on the ground, his guard up as his pace increases. Bucky's brow furls as he tries to keep up.

"Will it work?" he asks, wondering what could have upset Steve.

Steve slows abruptly, seeming to recognise the march he'd fallen into. "Yeah," he says again, his shoulders dropping.

He offers Bucky something of a smile, his eyes still laden with a worry Bucky can't decipher. "He's got a shield for me too. Some kind of super rare metal. Uh, vibranium I think he said."

Bucky falls into step with Steve, trying to guess what is bothering him. He wishes he could still smell him. Even though he can read Steve's body language he still feels like he is flailing as he tries to navigate the conversation. For a moment Steve opens his mouth as though he's about to say something, but he doesn't.

"Hey," Bucky says quietly, Steve's eyes darting up to his for the first time since he got here. "You don't gotta worry," he hazards. "Command has already approved the team and the mission. With Howard's fancy shield we'll be able to make a considerable dent in Hydra." His mouth crooks up. "Captain America's gonna be more than just a stage name."

Steve pauses and Bucky takes the chance to clasp his shoulder, scenting him in the same comforting manner as before.

He feels Steve relax under his touch and Bucky gives his shoulder an extra squeeze. "You're already more than a stage name anyway," he smiles, trying to keep his scent as positive as possible. "The Commandos are ready to follow you anywhere."

Steve breathes in and lets out a sigh. He flexes his jaw and gives Bucky a sad smile, pulling away from his hand. "Even though I'm an omega?"

Bucky steps back in surprise. "Is that what's gotten you into a twist?" he asks incredulously. "Pal, you could be the most omegan person to ever live and they'd follow you through fire and back. You already dragged them out from Hydra. Nothing else matters."

Steve lets out a small chuckle, his expression clearing somewhat. He breathes in, his jaw flexing. "Command is a different story."

Bucky shrugs. "Well sure. But that's their problem. And they don't gotta know."

Steve glances back towards the warehouse, his gaze distant as he shoves his hands into his pockets. "Yeah," he says quietly.

oOo

Bucky is certain Steve hadn't told him what's wrong. When he thinks about it, Steve hadn't actually told him anything. He'd just given it his best guess while Steve had clammed up.

He sees Steve periodically over the next two days and something unseen is definitely weighing on him. It reminds him of how Steve had been when his Ma was dying. His face is set and his shoulders straight, everything about him stoic and silent as he tries to shoulder the entire weight of the world.

I can get by on my own, he'd told Bucky after Sarah had died.

Thing is, you don't have to, he'd replied.

Because Steve doesn't have to do it alone. No matter what he thinks. Bucky doesn't know what is going on now, but he knows Steve is hurting somehow. He just wishes Steve would tell him about it.

(He can't blame him much though. He still wakes up with the chill of a metal table at his back and Zola's grin behind his eyes and he has no plans on revealing that any time soon.)

He catches up to Steve after another bar night with the Commandos. They have a mission scheduled in two days and had taken the opportunity to get in one last night of revelry before flying out to fight Hydra. It's late now, the streets dark and quiet as the last few patrons stumble out of the bar. Bucky waves at Gabe and Dugan before turning to find wherever Steve had snuck off to.

He finds him a little ways from the bar, standing over a bridge, his hands in his pockets. The night is dark, most lights muted or shuttered due to the raids. Steve's face is in shadow when Bucky steps up beside him, the dim light of the stars reflecting off the water below.

Steve's scent is absent as usual and Bucky lets himself breathe in the smell of the water and the streets of London. Steve is silent beside him, completely unmoving as he stares out into the night. Bucky doesn't know what to say. The stillness feels oppressive and he shivers as the night's chill nips at his neck.

"We should probably head back," he says eventually, his voice hushed. Steve glances at him, his face dark and unreadable. Bucky sees his shoulders heave a sigh and he hears him mutter under his breath.

"Guess time's up."

Bucky tilts his head, his brows pulling together. He bites his lip, trying to keep his frustration out of his scent. Something is eating at Steve but he won't tell him what.

He breathes in and waits for Steve to lead the way back to the hotel the SSR had put them up in. It isn't typical accommodations for soldiers, but the SSR was already keeping Howard and his whole crew there, so it hadn't been much of a stretch to station Steve and his team there too.

The sound of their boots echo on the cobblestones, search lights cutting through the night sky above them in an ever-vigilant search for enemy bombers. Bucky tugs his jacket on tighter and gives Steve a once over. He'd been quieter than usual in the bar—even with the Commandos around—and now he continues to be reserved and withdrawn.

The hotel appears a few blocks away and Bucky gives up waiting for Steve to speak up.

"Is it the mission?" he asks bluntly, hoping that that will force something out of Steve. Their newest orders will be Steve's first time officially commanding a mission. Bucky knows that he'd passed the Captain's test and earned his rank properly, but he's got to be nervous going into the field like this.

Steve's steps falter at his question. He glances at him and sighs, his shoulders hunching.

"I'll be fine," he says softly. Not a real answer.

He seems to nod to himself, his head lifting as he strides more determinately towards the hotel, his jaw clenching. "It'll be fine," he says more firmly, his eyes narrowed. He swallows and Bucky feels like they're talking about two different things when Steve adds quietly, "I can do this."

"Steve?" he asks uncertainly. Steve stops a few feet from the entrance, turning to look at him. His eyes are hard, barely visible in the dark. He looks angry, but Bucky doesn't know why.

"You know… they would've put me in a lab if it wasn't for the USO tour," he tells him suddenly. Bucky's stomach knots in anxiety at the reminder of the seemingly ever-present threat of labs. Whether from their side or the enemy's.

Steve's gaze shifts past Bucky and he breathes in, setting his shoulders. "I wanted to be of real use, and the only way that's going to happen is if no one knows I'm an omega. If they find out, I'd be thrown back into a lab so fast it'd make my head spin."

Thrown by the abrupt topic change, Bucky doesn't quite manage to keep down his growl. "It shouldn't be like that," he mutters, wondering if this is the root of Steve's recent melancholie.

Steve sighs and looks down at his feet. "No. It shouldn't," he agrees. He looks up and catches Bucky's eye. "Maybe…after all this is over, we can tell everyone. I won't have to hide that I'm an omega.''

There's a desperation there that Bucky can't follow. He nods anyway and Steve looks back up at the hotel, an indecipherable look on his face.

"Just… gotta keep it quiet a little longer," he murmurs.

Later, in his room, Bucky stares up at the black ceiling, unable to get their last conversation out of his head.

He supposes he can never understand exactly where Steve is coming from. He will never be forced to hide his identity or risk facing major unjust consequences, but the way Steve is acting still confuses him. If the unequal secrecy is all Steve is upset about, then that would be one thing. But Bucky thinks there is more to it than that.

Steve had been visibly angry about his situation when he'd rescued him from the Hydra factory. He'd been annoyed and chaffing under the restrictions placed on him, not solid and silent in resignation.

Bucky can't think of what could have happened to make this most recent mission any different from the off-the-cuff one Steve had run in Italy. He still has to hide his true identity to prove himself. If anything, he's now getting more recognition because Command is actually willing to listen to him and put him in the fight. Which is what he wanted.

So why is he upset?

He falls asleep worrying about it, his mind unable to put the issue away.

It is a few hours later when he wakes up again, tense and on edge. Every hair on his body stands on end and he freezes in bed.

His room is dark, blackout curtains drawn over his window. He can't see but he can hear the sound of breathing and sense another person in his room, his instincts kicking his pulse into overdrive.

The unfamiliar scent of another alpha reaches his nose and he snaps into action, pushing himself up. His hand is inches from the lamp at his bedside when a muffled whimper cuts through the pounding in his ears. His scent, which had been pouring aggressive and defensive pheromones into the air, gets cut with a heavy dose of confusion.

His hand shakes and he switches on the lamp. Light floods the room. Bucky's brain stalls as it reveals a blond, crumpled heap by his door.

"Steve?"

AN: I have been writing this prequel since January and I'm finally ready to share it with you! The angst/hurt/comfort is strong with this one.
I hope you enjoy reading this!

This fic is complete and will update on Mondays!