DISCLAIMER: I do not own Harry Potter or the Marvel Cinematic Universe. Any affiliated characters or canon components are the property of their respective franchise owners.

This fic is a canon-divergent AU for both verses. Some elements from the canon storylines will still have taken place/be present, others will not. Here's to hoping what's what becomes clear as the story goes on! XD

*This is also my first crossover, so please be kind.

Loki Fans: His part is smaller than the other two main characters for the early bits of the story, but I promise he will get much more 'screen-time' as the fic progresses.

Chapter One

The Worst of Many Bad Ideas

Bucky's eyebrows shot up as he looked over the file. "Loki?"

Sighing, Steve pinched the bridge of his nose. Bucky had just gotten himself untangled from all this, and here Steve was pulling him back in. "I know, I'm sorry, but we need someone we can trust."

With a frown, Bucky flicked his gaze toward the window. On the other side, the rest of the team—waiting for Steve, and for Bucky's answer—conspicuously turned away, as though they all suddenly found the street behind them utterly fascinating at the same moment.

"But they don't trust me."

Steve's shoulders drooped. Damn. He never could lie to Bucky. "Fine," he said, shaking his head. "I trust you, and they're low on options."

Bucky nodded and sat back. That wasn't exactly what he wanted to hear, but at least it was honest. And, after everything he'd done—had been made to do, really, but that was a matter of semantics, he supposed—he knew perfectly well he couldn't expect any other response.

"Look, I didn't even want to bring you in on this, but we're operating on one man's suspicions. There's no way to report this through official channels, so we need someone who isn't official."

"Fury can't possibly have okay'ed this."

"Well, we kind of left him out of this decision," Steve admitted, dropping his gaze to the floor for a moment. He wouldn't mention the blanket response they'd gotten when they'd approached Fury about this potential problem. The party-line these days was about how resources were tied up in rebuilding SHIELD, and investigating their nifty new wormhole tech. Well, almost all—it was also suggested that their team had more pressing matters to deal with than chasing ghosts.

Or—Steve's personal favorite response—they all had itchy trigger-fingers after everything they'd dealt with, and were seeing enemies where there were none. He was also far too aware that Fury was only one of many who didn't want Loki to still be alive. Refusing to give a scant possibility the time of day should hardly be a surprise.

Once more, Bucky glanced through the glass. Thor had his head down, but from the angle, Bucky could see a look of pained concentration on the Asgardian's face. God of Thunder, trying to eavesdrop. Yup, that was dignified.

The man had reason to believe that his wicked step-brother had somehow survived the events on the Dark World. However—because that sentence, by itself, didn't smack of insanity—since Loki hadn't made any overt moves, as of yet, that had to mean he was up to something.

Not that babysitting the planet while the Avengers tripped off-world didn't sound like loads of fun, but . . . .

Shaking his head, Bucky braced his gloved hands against the table and pushed up to stand. "There's no way leaving me in charge of anything is a good idea."

He was still having nightmares about crimes he could only recall in snippets, or didn't remember, at all, but which others had delighted in filling him in on in graphic detail. Several times he'd stopped himself just short of lashing out at those around him after waking dreams.

Steve really couldn't expect him to do this. Even repaired, as he was considered, Bucky knew he still had the potential to be dangerous. The Avengers should stick him in a box and leave him there, and they all knew it.

But then, he realized that should also probably tell him how desperate they were.

"Please, Buck?" Steve met his friend's gaze, his expression serious. "He could be wrong, it could be nothing. Maybe he's just paranoid, but I can't leave this to chance."

Hell. I'm in hell. Setting his jaw, Bucky shook his head again. He couldn't believe he was going to say this. "Okay." He blinked a few times as he swallowed hard. "I will keep an eye out, and if I can help, I will. But that's all I can promise."

The tension drained out of Steve, but he didn't smile. Instead, he dug into his pocket and pulled out a few folded pages. He was all too aware of Bucky's eyes narrowing, following the movement as Steve set the small paper bundle atop the file.

"Should I even ask?"

Rolling his eyes toward the ceiling, Steve said, "Thor had . . . visions of a few locations. He thinks Loki might have be at one of them, or have plans that involve them."

Nodding, Bucky—despite how very much he disliked the situation—held in a chuckle. Now he understood the look discomfort that had just flitted across Steve's face. Gods and visions? This just kept getting better and better!

"Don't worry, they're all in the city. No unfamiliar territory for you. It just wasn't like we could include this in the dossier."

Sighing heavily, Bucky nodded as he unfolded the hand-written pages.

Huh. Asgardians had crappy handwriting. Who knew?

As they walked away, Tony didn't even glance over his shoulder toward the diner. He didn't want to trust anything to the Winter Soldier. Not a goddamned thing.

Shit, he was actually hoping Thor had simply lost his mind, wasn't he?

"You know this is a really bad idea, right?" he finally asked, breaking the tense silence of the team.

"We've been over this. If the threat's real, then we don't have much choice," Natasha said, her voice low as she exchanged a look with Steve.

"I know it's a bad idea." Steve nodded, a frown gracing his lips. "And so does he."

One Week Later . . . .

Snapping the tome shut, Loki dropped his heels down from the tabletop and sat forward. The orb had lit up. After so many days of nothing since finding the relic, at last something was going his way.

He grinned as he snatched up the glass sphere. Plumes of varied colors swirled, shifting and morphing until they formed into a moving image.

There she was, the last of the Earthbound Witches. A slender young woman with wild golden-brown hair—she appeared tired and nervous. A thoughtful frown tugged the corners of his mouth downward as he gave a half-nod. That should work to his advantage, actually.

Holding the orb closer, he watched as she stepped out of a large mass-transit vehicle. Right out onto a New York street.

Teeth sinking into his bottom lip, he stood and began gathering his things. There was no way to tell when this would happen, only that she was the one necessary, and she would be at that location, soon.

Best he be there as quickly as possible. How nice it would be for her, to have someone greet her the moment she arrived.

And Three Days After . . . .

Hermione closed her eyes, fidgeting as the bus rolled to a stop. There was nothing worse than this, she was sure. Pulling her jacket more tightly around herself, she opened her eyes again, looking out the window as the wheels kicked into motion beneath her, once more.

After the last few times, she wasn't certain where the map she'd created was leading her, anymore. She'd spelled it to lead her to other Muggle-born witches and wizards, but . . . .

Swallowing hard, she blinked rapidly to keep her tears at bay. Maybe the reports after the Ministry's fall had been correct, after all. Voldemort's dark influence had traveled so far before he'd finally been stopped. That it might've seeped through the whole of the Wizarding world was terrifying.

Even so, it was difficult to grasp that she might truly be the only one left.

Chestnut eyes tracing rooftops against the sky, she tried to quell the sick feeling of ice churning in the pit of her stomach. Her own escape . . . . Well, she was certain she'd had unspoken help. If she hadn't acted right then, she might be dead right along with the others.

Those previous searches had brought her to dormant magical Artifacts. Muggle antique shops were usually lousy with them. She'd bought the items, just in case they might prove useful in her search, but other than that, her mission was proving a spectacular failure.

Honestly, she wished she had taken Harry's offer to go with her. But the young man with the lightning bolt scar was far too recognizable to their kind.

The Dark spell might've been broken, but she couldn't take any chances.

A pulse jolted through her, and she started. Opening the bag she carried 'round her wrist, she rummaged about, glancing at the other passengers as she did so. The last thing she needed was for any of these Muggles to see her up to her elbow in a bag that was no bigger than a textbook.

Extracting the hand-drawn map, Hermione unfolded it delicately. She held it tilted toward her, so no one might glimpse the blinking spot of red glaring from the sepia parchment.

Trailing from her currently-moving location, to the indicator on the map with a fingertip, she looked out the window, once more. The scale of her drawing meant whoever—or, disappointingly, whatever—she was looking for was somewhere close to the next stop.

She inhaled deeply, trying to steel her nerves as she pressed the chorded tape to alert the driver. It seemed a small blessing to her that American Muggle mass-transit really could take one anywhere. Her limbs screamed at her as she stood from her seat and began making her way to the rear door of the bus.

She hadn't had a good night's sleep in so long; she could swear her muscles had aged decades from the lack of rest, alone.

As the bus pulled to a stop, she found she once more had to beat back a sick feeling of trepidation. Hermione frowned. She wasn't normally this edgy, even as exhausted as she was.

No. There was something . . . . She could sense it winding through the air, only not clearly enough to tell what it was.

Something was going to happen today.

Bucky rounded the corner, shaking his head as he started down the block. He'd been routinely circling the locations, and so far nothing. But this neighborhood was the one he liked the least. It was quiet, and dull . . . . Rundown apartment buildings, hovelled mom-and-pop shops, small factories; passersby were scattered, few and far between. Even traffic through this section of the city seemed scarce.

The subdued environment would be enough to make anyone edgy, he thought. Like there was something wrong with this place.

But then Bucky saw him. Stepping out the door of a little shop was Loki—in one of the predicted locations. Bucky's frame slumped a little. Fantastic. Thor's suspicions had been right, after all.

The jet-haired man wore a determined look on his face as he crossed the street and continued on at a steady pace. Not rushed, but at an obvious, calculated stride.

Bucky was familiar with that sort of movement. Hunter and prey.

Loki was looking for something, and knew where to find it.

Glancing around, Bucky took stock of the area—noting street corners, storefronts, doorways, alleys, even the cars parked nearby, and a long-unfinished construction site in an empty lot—before moving to pursue Loki.

After a few blocks, Loki paused, watching something. Bucky slowed his footfalls, following the other man's line of sight. A city bus was rolling to a stop on the opposite corner, and something about that caused a grin to curve Loki's mouth.

A spike of alarm shot through Bucky. Loki wasn't looking for something. He was waiting for someone.

He clamped down on the instinct to confront Loki. If he was as strong as that file said, this could turn into a combat situation, fast. Drawing attention to himself with that sort of grand-scale melee was not an option. Steve and the others would probably want whatever information the target could give them about what was happening. Bucky didn't imagine they would be thrilled if the person Loki was hunting was hurt—or killed—in the scuffle.

But that left him precious little in the way of plans. Once more, Bucky looked around. The only option might be to catch Loki by surprise.

Hermione stepped onto the sidewalk, the stone surface beneath her feet so pitted she could feel it through the soles of her trainers. The door of the bus snapped shut behind her and she immediately found herself looking about for a quiet spot to check the map, again.

Her face fell as she took in the area around her. It seemed all of it was a quiet spot. Unnerving, really. "Bloody hell," she murmured, forcing a gulp down her throat.

"My dear, there you are," a voice called from behind her in a warm, jovial tone.

The fine hairs on the back of her neck stood on end and her stomach knotted. She didn't have a wand, anymore. Her captors had broken it . . . . She had a book somewhere in her bag on wand-crafting, but she'd had yet to master that, leaving her only able to cast small charms, at best.

Enough to create a distraction if things got sticky, she reminded herself as she pivoted on her heel to face the speaker.

A tall, lanky man with long, black hair and green eyes approached. Those features struck at her heart a moment. So much like Harry's . . . . but as he drew closer, her pulse hammered in her skull.

Something was wrong, here. Whatever he was, he was no wizard. Putting the hand with her bag behind her, she backpedaled a step. He was so pretty, though.

But then, so were the Malfoys, she thought, being deliberately cruel to herself to keep her brain working.

Gauging her reaction to him, Loki held up both hands in a sign of surrender as he drew near. "No need to fear me. I know what you are, and of what you are capable."

Hermione darted her gaze about, before meeting his eyes. If he knew, then it was probably best she not let on about the no-wand issue.

"A wise person always treats a stranger addressing them as a friend with caution."

Loki's brows shot up as he nodded. He stilled his steps, his hands still up. "Then, perhaps, I will let you come to me?"

She lifted her chin defiantly, refusing to show how unsettled his demeanor made her. "And why would I come to you?"

Frowning, Loki made a tutting sound. Dropping his arms, he folded them across his chest, achieving a much more relaxed posture.

Hermione lifted her heel from the ground, balancing on the ball of her foot and shifting her weight to her front leg, ready to bolt. Despite his words just a few moments ago about knowing what she was capable of, he had absolutely no fear of her.

And that was terrifying.

"Because," he said, offering her a charming grin, "you have nowhere else to go, do you?"

How could he know that? Who was he? She wanted to spit the questions at him, but there wasn't time. She had to keep moving if what she sought wasn't here.

She narrowed her eyes, concentrating on him as she began to speak one of her charms, "Confund—"

The sharp crack of metal on bone cut through that single word and she stared in shock as the dark-haired man crumbled to one knee.

She shook her head before she looked up. Honestly, she'd been so focused on his face, she never saw the strike coming. Behind him stood another man, a little shorter than the first, but broader of build, with brown hair just long enough to brush his shoulders.

In his hands he clutched a hunk of metal that rightly looked far too heavy to be wielded with ease, let alone used as a weapon. And how the black-haired man wasn't dead from that hit was beyond her.

Dropping the shorn beam, Bucky made a waving gesture, signaling the girl toward him. "Move!"

She jumped to follow the instruction—whoever this man was, he didn't emit the strange, intimidating aura the other one did—giving the stunned man a wide berth. Not wide enough, she realized too late.

Loki shot out a hand, putting strength into the motion, just as she passed him. Her slight, Midgardian frame connected with his outstretched arm and she was knocked backward.

Hermione landed with a resounding thud, the side of her head impacting the broken pavement. She winced at the pain rocketing through her skull as her vision blurred.

"Shit," Bucky hissed from between pursed lips as he bent to reclaim his discarded weapon. So much for avoiding combat.

"I do not know who you are," Loki whispered, a vicious grin twisting his lips—his head actually hurt. Whoever this man was, he would pay. "But this girl is mine!"

Bucky swung as Loki climbed to his feet. He nearly expected it when Loki caught the shorn hunk of metal in his bare hand. He didn't need to knock Loki out—there wasn't time for that, he had to get that girl away from here—he just needed to stun him, again.

I do not know who you are, Loki'd said. Good, then he wouldn't know what was coming. Pulling on the beam with his right arm, Bucky swung around with his left, catching Loki in the jaw.

Shocked, more than hurt, by the force of the punch—this was no simple Midgardian—Loki slackened his grip.

Bucky took the opportunity, wrenching the beam from Loki's grasp. He swung again, striking Loki hard enough to propel him several feet. Loki landed hard on his back, a surprised cough tearing out of him, but Bucky was already moving before Loki had hit the ground.

Rushing to the girl's side, he hoisted her up; he didn't have the luxury to worry about her dazed expression, or the crimson trickling along her temple, at the moment.

As he tossed her over his shoulder, he flipped through the mental catalog he'd made of the area. He took off at a run, still hefting his makeshift weapon in his free hand.

Bucky glanced back just as he rounded a building on the nearest corner. He had to move faster, Loki was getting to his feet.

Dropping the beam and shifting his hold on her to carry her in front of him—the last thing he needed right now was for someone to think he had hurt this girl—he spied a man just pulling up in a car that would have to do.

As the man switched off the ignition and climbed out, Bucky ran to him. The driver was too startled to react as Bucky snatched the keys from his hand and opened the door. He could just dump her in the car and drive off, but maybe a more human approach was likely to buy them a little time before anyone alerted the authorities.

"I'm sorry," he said, purposely rushing his words so the man had no moment to gather his wits and argue. "She's hurt bad, I need to get her to the hospital. I'll bring your car right back here once I drop her at the ER. I promise."

He pushed the girl through onto the passenger seat and hopped in, slamming the door shut. At this rate, he was going to kill her by accident.

Shoving the key in the ignition, he started the car and peeled off. In the rear view mirror, he could see Loki rounding the corner just behind them. There was little relief in the image of the now definitely angry Frost Giant-slash-Asgardian growing smaller, and eventually vanishing in the distance.

After several minutes of non-stop driving, he pulled to a halt at a red light. Looking at the girl in the passenger seat, Bucky frowned. She was worryingly still.

Reaching out, he touched a two fingertips to the side of her throat. He let out a breath. She was alive, that was good, just unconscious.

Taking a moment, he leaned across her, securing the passenger side seatbelt around her and wiping the blood from her face with the sleeve of his jacket. He couldn't exactly pop up on SHIELD's doorstep. His own history with that organization—they weren't likely to believe a word he said about anything without Steve there to back him up— and the team's choice to leave Fury out of their decision to bring him in on this had seen to that. Bringing her to a hospital, though it would be the smart thing, didn't seem like an option, either. What he'd overheard Loki say to the girl made it sound like perhaps she was on the run from something.

I do not know who you are, but this girl is mine! Whatever that something might be, it was clear that she was what Loki was after.

He had to put her somewhere safe, out of Loki's reach, until the others came back. Bucky winced at the thought as he glanced out each side of the car, in turn. Would that mean leaving the city?

The light turned green, and he hit the accelerator, shaking his head as he locked his gaze on the road.

He'd just kidnapped a girl, and stolen a car. He doubted that doing those things in the name of saving the day made any of it right.

His shoulders slumped and he chewed the inside of his lip. Yup, Steve was going to kill him.