Author's Note:

So this (rather ambitious) project takes place in an alternate universe (obviously) with some elements of both the MCU and the DCEU. Basically, it assumes that Steve (Rogers) was ineligible to join the military due to his health, but that he was covertly given the Super Soldier serum and did serve, but that after the war/plane crash/being frozen, he never resumed his Captain America duties after waking up. It also assumes that Bucky was captured, brainwashed by Hydra, completed some missions, but then was placed in suspended animation in anticipation of a third world war which never occurred, until he was rescued by the same people who rescued Steve and was rehabilitated. It also assumes that Diana did basically what she did in the Wonder Woman film and went on to have a reasonably normal/quiet life without doing any superhero type activities (although she could and would have if the need was there). In this universe superheroes are not commonplace, so there's no Avengers/Justice League, just some people, Bucky, Steve, and Diana included, who happen to have remarkable powers of one variety or another.

Late on an otherwise unremarkable Sunday night in the middle of August, someone knocked on the Rogers' door.

"Don't answer it," Steve said sleepily, still engrossed in a History Channel documentary about the Kennedy family. "Who calls on someone at eleven pm?"

It can only be bad news, Bucky thought to himself, but got to his feet anyway. "It might be important," he said by way of reasoning, and then, "besides, we could take whatever's out there, right?"

Steve chuckled nervously, but didn't otherwise make any move to stop him, so Bucky opened the door. "Can I help you?" he asked with all the crotchety old man vitriol he could muster. "You know it's l—"

Standing in front of him, suddenly, was the most remarkable woman he had ever seen—so remarkable, in fact, that he stopped dead in his tracks and just stared at her with his mouth agape for a moment. It wasn't just that she was beautiful—which she was—but there was something else about her that was so magnetic, so powerful, that all he could do was stand there and look at her, certain that she could not possibly be of this world.

The woman, for her part, seemed completely unbothered by Bucky's staring. "Are you James Buchanan Barnes?" she asked, stepping into the foyer. "I need your help."

"Sorry," Bucky said, recovering himself, shaking his head, "who are you, exactly?"

"I am Diana, Pr—Diana Prince," she said, "And I need your help."

Having recovered his senses, Bucky's first thought was that he should kick her out, but instead, for whatever bizarre reason, he asked instead, "Uh, what kind of help?"

"I had heard that you are…unusual," the woman—Diana—said, taking off her shoes, setting them neatly in the corner. "And I believe that your gifts could be of use to me."

"Unusual? I don't know what you're talking about. I think you have me confused for another James Barnes, uh, you need to leave…no! Don't go in there!" because the woman was heading straight for the living room. He trailed after her. "Lady, you can't just—what are you—oh god."

"You must be Steve Rogers," she said warmly to a very dumbfounded Steve. "My name is Diana, and I am so excited to meet you and James. I've read so much about you."

Steve shot Bucky a "what the hell is going on?" look over Diana's shoulder, but all Bucky could do was shrug, just as absolutely lost as Steve was. "I—sorry, it's nice to meet you but what's your business here?" Steve asked, trying to keep his voice calm and bright—his PR voice, as Bucky called it.

"I came to you because I believe your gifts could be of some use to me," Diana said again. "I have reason to believe that a…colleague…of mine was lost under similar circumstances and I was hoping that you could aid me in a recovery mission."

That certainly got Bucky's attention. He sat down next to Steve. "We're listening," he said. "Please sit down."

Diana did, continuing. "During the first World War, I along with a group of gentlemen, aided in an armistice mission in Germany," she began. "The mission was successful but—as with all missions of war—was not without casualties."

Bucky and Steve exchanged glances, recognition dawning at the same time as they realized who, exactly, was sitting in their living room. They had heard of this so-called "Wonder Woman", of course. During their war, the second one, there had been plenty of jokes to go around about when she was going to show up—after the first war, she had all but disappeared, leading most people to believe that she was a myth, that someone had seen that now-infamous photo and invented their own narrative. But Bucky and Steve had always known better. They, after all, had firsthand experience with the kind of stuff that most of the guys in their platoon had only ever read about in comic books. Still, no evidence of her had ever surfaced besides that photo, and it was one thing to have a belief that she could have, at one time, existed and quite another to see her sitting in their living room almost a hundred years later.

"One of my companions, Steve Trevor, was lost in this mission, or so it seemed. He was flying a bomber full of gas and sacrificed himself to save many others. But no evidence of him, or his plane, was ever found. And believe me, I have looked."

Steve nodded sympathetically, reaching for and squeezing Bucky's hand. Hadn't he been in the same position not so very long ago? "So how can we help?" he asked.

Diana smiled warmly at him. "I believe it is possible that Steve was taken by a prototype of the group who took you," she said, gesturing to Bucky. "And I believe that he could still be alive—well—"asleep" as you were. I am asking for your help in finding him."

Bucky hesitated, glancing at Steve but finding his face unreadable, and there was then a moment of uncomfortable silence before Steve finally spoke. "Diana," he said gently, "it's been a long time, and people who go through what we went through…they don't—it's a really delicate thing, and I'm not sure…" he trailed off, and Bucky picked up for him. "There's a pretty good chance your friend's brain is never going to be the same again, even if he's still alive. The mind control techniques these people use are…pervasive. Even if he's still alive, if they did or said anything to him before he went under, or even if they used something—a gas, a serum—while he's been under, he could be a totally different person than the one you knew, and…it's gonna take years before he even vaguely resembles the person he did back then." He thought, briefly, of the endless days and nights in the psych ward, of the fear and confusion, of the nightmares that still plagued him some nights. He thought of the helpless, hollow sound of Steve's voice when they talked on the phone while he was in the hospital, thought, too, of Steve's own sense of being out of time and what his comparatively innocuous recovery must have been like.

"Bucky's right," Steve added. "Even if your Steve wasn't being influenced by Hydra, coming out of a sleep that long can destroy a person, too. It's a lot to consider, Diana, and I dunno if it's…if the benefits outweigh the risks."

"I know it won't be easy," Diana said with just the slightest hint of impatient insolence. "I sought you out, did I not? I read the research and all the articles. And if Steve is alive, somewhere, especially with those evil people, I need to get to him. I will do it with or without your help, but with your help I think there are greater chances of success." She patted her bag. "I have a plan here, if you'd like to see it."

Bucky and Steve glanced at each other again. "Give her a chance," Steve said into Bucky's ear. "Let's hear her out, we're not committing to anything just now."

"Okay," said Bucky, "Show us what you've got."

Diana began taking things out of her bag—newspaper clippings, notes, maps, and photographs, spreading them across the coffee table. "I've been tracking the movements of the Hydra group for a number of years," she began. "As we already know, there are bases in the following locations—" indicating them on the map "But I have reason to believe that operations are still being carried out from the location of the German High Command during our war." She spread some of the photographs out on the desk. "Although the building supposedly now houses part of the German Embassy, it appears that there's no record of this address being used to conduct Embassy business anywhere. They've forged enough documents to make it look legitimate—"

"—Unless you look too hard," Bucky finished, sighing. "Sounds like Hydra to me." This whole thing was already giving him a headache.

"Right," Diana affirmed. "Now, located about five miles back in the words…" she rifled through the papers until she found what she was looking for. "…is this." She held out the photograph and Steve took it out of her hands, studying it. It looked like an otherwise unremarkable storage shed, perhaps a hunting shack, albeit better maintained than most. "And this is…?" he asked.

Diana hesitated. "This is what I'm not sure of," she began. "The area around the, whatever it is, is heavily guarded and protected. Cameras, fences, underground currents, everything you can imagine. It's obvious that whatever it is, they don't want to make it easy to get to, and I believe it could be a training or prisoner holding facility, an underground one—like the one that you were in in Siberia, James."

"How do you even know…?" Bucky asked, somewhat awestruck.

"Research, James," Diana said impatiently. "I did my research. It wasn't even hard to find once I knew what I was looking for."

Steve snorted and Bucky elbowed him in the side. "Not funny," he hissed.

"Kind of funny," Steve whispered back. Diana watched this from the other side of the room, smiling patiently.

"Are you done?" she asked, and they both nodded sheepishly as though they were school children being chastised by a teacher. "So, as I was saying, I believe that this may be where Steve—my Steve—is being held. I can't do it alone, but I believe that with your special talents and knowledge, we can infiltrate the base and rescue Steve and any others that may possibly be held there. Would you be willing to help me?"

There was a long pause. "Can we have a moment?" Steve asked, finally, and Diana nodded. "I'll wait here," she said.

"Thanks." Steve got to his feet, dragging Bucky behind him, and the two men ducked into the kitchen.

"God, she's sassy," Bucky complained.

"Look who's talking." Steve looked like he was trying not to burst out laughing. "But she has a valid point, Buck. All signs here point to that building having something to do with Hydra, and if there are prisoners there, even just one prisoner…isn't it our duty to do something about it? Like she said, it's not like there are many people out there like us. Until today, we thought we might be the only ones, you know? I know that we never wanted to use our powers anymore but Buck…I don't know. I just feel pretty strongly that we should do something."

"Yeah." Bucky still looked a little uncertain. "But Steve, how do we even know she's legitimate? I mean, it could just be a giant trap, she could be Hydra, we just don't know. I don't think it's safe…"

It was Steve's turn to look at Bucky as though he had three heads. "That woman single-handedly ended the first world war, Buck. We've all heard the stories. And besides, I just…feel like she should be trusted. I can't explain why, or how, I just do."

Bucky faltered. He'd felt that, too—it was something he'd only ever felt one time before: the first time he met Steve. And his instincts hadn't been wrong then. "Okay, fine," he said after a moment. "Let's do this."

Steve hugged him tight. "You won't regret this," he said into his husband's hair. "I promise."

"We'll see," Bucky muttered, prompting a laugh from Steve as they walked back into the living room, sitting opposite Diana again.

"We're going to do it," Steve announced, not giving Bucky enough time to change his mind.

Diana's face lit up, and she rose, embracing them both. "I can't thank you enough."

"I do have one question, though," Bucky began, ignoring the dirty look Steve was giving him. "How did you find out about us—about our…gifts, I mean? Because as far as we knew there was no one else like us, and it's not like there's any kind of registry or…I'm just wondering how you could have found this out."

Diana nodded. "When I first began researching, it seemed it would be impossible to successfully complete such a mission because I thought that I was alone. But as I began to read more about the experiments conducted by Hydra, your name, James, kept coming up. And your name led me to your platoon, which led me to you, Steve. And finding you meant finding your medical records…even the classified ones. And when I learned that you were still alive, I knew that you could be the ones to help me."

Both men nodded solemnly. This time, it was Bucky who spoke first. "It would be an honor to help you, Diana."

"Thank you." She began gathering her paperwork. "I will be back tomorrow. Get some rest, we have a long, long journey ahead of us."

"We will see you tomorrow," Steve said, walking her to the door. "Travel safe, Diana."

"Thank you, Steve," she said, hugging him. "Sleep well."

And then, just as quickly as she'd come, she was gone.

"What the hell just happened?" Bucky asked, coming up behind Steve and wrapping his arms around his waist. "I mean, what the hell did we just sign ourselves up for?"

"I have no idea." Steve's voice was grim. "I just hope that whatever it is, we're ready for it."

"Yeah," Bucky agreed, taking Steve's hand. "Let's get some sleep now. Who knows the next time we're going to do that."

As Bucky fell into his uneasy sleep later that night, Steve sleeping as peacefully as could be beside him, all he could think about was how very unprepared to go back to war he was.