Written as a gift-fic for dancewithwolvesx on AO3 for the Loki/Sif Mischief and Mistletoe fic exchange! The prompt was essentially "write whatever you want, just don't kill them." So here's my attempt at a heist/spy AU. Everyone should go check out all fifty of the works created!

Sif had a shadow. A sleek, annoying, arguably handsome shadow. And she desperately wished to be rid of him.

Swirling her whiskey in its glass, she sighed trying not to dwell on his latest appearance. This was an undercover job with the feds. It was supposed to an easy task, grab the jewels before a private party found out about them, in and out in no time. But she had barely cracked the code on the outer security doors of a vault before he had waltzed past her with a sack slung over his shoulder.

"Sif!" he had greeted her as an old friend, when in fact they were no such thing. In truth, she considered him the opposite. "Lovely to see you again! When was it last? Prague? Must say I much prefer this color hair on you, that blonde wig was absolutely atrocious."

His posh voice grated on her nerves almost as much as it seemed to warm her cheeks.

"Fuck off, Odinson."

"Ah charming and eloquent as always." He bowed in her direction. "Now if you'll excuse me, I have a client waiting for me." The wink and smug smile he'd given her had made her want to punch his face in. Sif always felt confident in her abilities and knew she was one of the most capable professionals in the world. Except for when he showed up.

The name of the game was extraction. Money, goods, and occasionally, people.

Sif was no secret agent but her skill set was valuable nonetheless. Her chosen profession left her balancing on the edge between criminal and hero. And working for a company that the government occasionally contracted with had certain perks. Namely free reign to do what was needed and a hefty paycheck for most assignments, both from private parties and from Uncle Sam.

She had quickly risen to the top of her rather infamous field, gaining notoriety for being one of the few females in the business. She was proud of her accomplishments and worked hard to maintain her client list.

The only time she had ever lost a job was when he was involved. Of course it was to be expected that other countries or organizations would be trying to get their hands on some of the targets Sif went after. But most of her competition was no competition at all.

The first time she saw him was at hotel bar in Paris, and she was browsing the room in heels and a blonde wig. She had actually been quite flattered when the dark, strange man had approached and began chatting with her, flirting with her.

She should have known better, been focused on her task, but she'd found it hard to reject this man who placed a warm hand on the small of her back as they moved to a quieter corner with their drinks. It was hard to remember why she was there at all when he whispered flattery into her ear. Until he had suddenly asked, "You don't mean to run from security in such ridiculous heels, do you? I was told you were smarter than that."

Sif was left shocked as he turned from her. His charm had effectively distracted her, allowing him to lead her across the room from the door she was trying to get to before he'd disappeared into the crowd. When she made her way back towards the door, he had burst out of it with a wild grin and a ruby in his fist.

"Au revoir, ma chérie!" He'd tugged on a strand of blonde hair on his way past, pulling the wig off of her head and effectively blowing her cover as he darted out into the busy streets.

Furious, she had drilled Darcy, whose skills as a hacker also made her extremely employable to a certain group of people and whom Sif often worked with before a job, for information.

"Who is this asshole?" she'd fumed.

Typing wildly, Darcy had spewed off all the data she could find on him. "Looks like the name is Odinson. Loki. Actually I can't tell if that's his real name or a nickname. Low Key? Loki? I don't know which one came first...also pulling up the name Silvertongue." She snorted. "Did he give himself that code name? What a douche."

And his appearances hadn't stopped. He had dropped out of the ceiling on the job in Berlin. He'd literally snatched the necklace from under her nose in Johannesburg.

She threw back her whiskey and tried not to let thoughts of this infuriating man keep her from enjoying the gathering, wanting to revel in the Christmas party in the city. But she couldn't muster up the holiday cheer with a bruised ego at having another treasure snatched out from under her nose.

"Noooo, you can't go!" whined Darcy. "Do you have any idea how hard I worked to organize this party? To even get Jane to agree to leave her lab for one night?"

Sif repressed the urge to sigh at her friend as she shrugged into her peacoat.

"I worked really fucking hard. And this is a kickass party!"

"It is. And I know you did. But I am tired and I don't want to be a black spot on your night."

"Alright, Scrooge," Darcy patted her arm sympathetically. "Try not to let him get to you too much, yeah?"

Sif smiled weakly before making her way towards the exit. She ran out into the snow, pulling the collar of her black coat up to shield her face from the swirling fluff. She stuck her hand out, waving for a taxi, her open coat fluttering in the harsh wind and cursed Darcy for insisting everyone wear their most "bodalicious" outfits out.

When the yellow cab pulled over, she quickly fumbled the door open and slid into the warmth of the backseat. Just as someone else slid in from the other side.

"This one's taken, pal," she chattered, rubbing her hands together.

"Might we share?" a smooth, maddening, voice intoned.

"Oh for fucks sake," she snarled, her head whipping around to see the one person she wished to permanently be rid of seated next to her. She could not believe this was happening. "Get out of my cab, Odinson."

"Come now," he crooned. "What harm is there in sharing a cab? We are both off the clock. Or at least I assume you are." He let his eyes rake up her body, from the smooth lines of her bare legs to where the silver sparkle of her dress brushed against her thighs to the spill and tumble of her loose hair. Sif rolled her eyes at his disgusting leering.

"No need for competition here." His eyes flicked back up to hers and his voice was condescending, as if he was reasoning with a child. "We can even drop you off first so you don't have to spend an extended amount of time in my presence."

"Oh no," she shook her head, "so you can case where I live and harass me there? I don't think so."

"So you live here?" he smirked, eyes dancing with delight.

Shit. "No," she snapped too quickly. Fuck. His grin spread.

"Right, well to my hotel first then." He leaned forward and gave an address to the cab driver before falling back against the seat. He turned towards her, angling his body so he lounged against the seat. His legs took up too much space.

"You look lovely. Celebrating Christmas Eve with family? Friends? A boyfriend?" he asked conversationally.

Sif slid her eyes over to him and smirked. "First you take my job, then you stalk me, and now you're trying to hit on me?"

"Trying? Oh no, my dear, I am doing better than that." Sliding across the backseat, he crowded closer to her, slinging an arm across the back of the seat, and Sif glared, her nose filled with his cologne, something minty and sharp, like snow. Confidently, he placed a long hand on the bare skin of her knee.

Perhaps it was the alcohol she'd imbibed at Darcy's party but Sif couldn't bring herself to push his hand away, to break his arrogant fingers. There was something undeniably attractive about him, all sharp edges and smooth lines. He looked elegant, dressed in a dark coat with the high collar turned up over a white button-up shirt and green scarf draped around his long neck. Sif found herself drawn to him.

"What's an attractive, dangerous woman such as yourself doing alone on a night like this?" his voice was silky as his hand moved up and under the hem of her dress.

"Flattery will get you nowhere," she remarked in a bored tone, ignoring the urge to squirm under his hand.

"On the contrary, my dear. I've found that it gets me everywhere. Including through doors and security to beat you to a target." His grin was smug, pompous. "Perhaps you should try it sometime."

"Don't act like you know me."

"I do enjoy watching you work. All of your clever lock picking and your brute force."

His hand slid slowly up her muscular thigh. And paused.

"I don't believe such a blade is government issued?" he wondered, his long fingers tracing the edge of the knife strapped to her thigh.

"It's from my personal collection. And I don't work for the government. Just with them on occasion."

His voice hummed in satisfaction. "So you're still a free agent like me?

"I am nothing like you," she tried to snap, but found herself growing short of breath at his teasing touch.

"You wound me," his hand slid higher and Sif contemplated the benefit of kissing him. To just get it out of her system and then move on. Stop thinking about the bastard.

"Shut up," she breathed out, frustrated.

He leaned closer to her, his eyes on her lips. "Make me." Sif's eyes fluttered closed at the sensation of his breath against her mouth and her heart jumped in anticipation.

Lurching to a halt, the cab pulled up to the curb and the driver rapped his knuckles against the plexiglass. Sif startled, pulling back and looking out the window towards the tall hotel building. Loki sat up, smoothing his coat, looking infuriatingly composed.

"Good evening, my lady. Merry Christmas." He lifted her hand to his lips before opening his door to the cold night air. "Until we meet again."

"There will be no again," she muttered to herself as the door slammed shut. She watched irritably as he glided through the sleek doors of the bright hotel before giving the cabbie the coordinates to her apartment, cursing the way her heart continued to hammer in her chest and the disappointment burning in her gut.

She was being ridiculous she told herself as she wrenched the door of her apartment open. He was just playing with her. As always. She angrily kicked her heels off and let her coat drop to the floor. She reached for the hem of her dress as she crossed the living room of her small flat heading towards the bedroom. As she pulled it up her hips, she froze. Something was not right. Something was missing.

She looked down and swore.

She inserted the magnetic key into the door of the hotel room as silently as possible before pushing the heavy door open. It had been easy to convince the man at reception that she had been out with her husband at a party and that the silly man, surely they had seen him just walk in, had taken her key with him and if it wouldn't be too much trouble to give her another copy, no need to wake up her beloved.

The room was dark, quiet and Sif pushed her back against the wall as she crept inside. She paused only briefly to let her eyes adjust to the darkness before moving forward, ready for an attack. Her eyes scanned the shadowed room, taking in the smooth white sheets of the empty bed.

"Ah, my lady. I did not expect to see you in my bedroom so soon." his voice came from across the room, but still she could not see him.

"You have something that belongs to me. You will give it back."

"And what's in it for me?" His voice seemed to slide down her spine.

"I don't kill you." Sif's eyes continued to sweep the room and she grew increasingly furious as she couldn't locate his long frame.

"Ah but I am the one with the weapon. I believe, I will be setting the terms of our exchange."

"What do you want? Information? The details of another mission for you to crash? You can't have it." She crossed her arms in defiance, prepared to stand her ground against his demands.

"Oh, no. No no. Something much simpler." His voice was the definition of nonchalance as he seemed to appear out of thin air, stepping into the soft moonlight near the large windows across the room from her, twirling her blade in his hands.

"You may have your blade," he intoned, "in exchange for a kiss."

Sif balked. "Are you serious?"

"Quite."

She sighed. This was ridiculous. Just another game, she was sure, but she could not discern the stakes. Her mind flashed back to the cab and his long fingers against her skin. She found all arguments dying on her tongue.

"Do we have a deal?" He continued to twirl her blade.

"Fine. Yes. We have deal."

As soon as the words had left her mouth she saw his hand flick, smooth and graceful. The blade sang as it flew through the air. Sif did not have time to react, only saw the silver streak whiz past her face.

The knife buried itself into the wall next to her head. As she turned to look at it, a long lock of her dark hair fluttered to the ground, sliced from her head by her flying blade.

Before she had time to lift her hand to free the knife, he had crossed the room in long graceful strides, looking every bit the predator. He invaded her space, placing one hand against the wall near her head as the other reached up to toy with her shorn lock of hair. Sif felt breathless.

"Apologies, my lady." He tucked the strand behind her ear before cupping her neck, his thumb against her racing pulse. "Now, I've made good on my side of the bargain..."

He leaned down until his face loomed over hers. Perhaps this is what she needed, she reasoned with herself again. To fuck him and get it out of her system. Get him out of her head.

With that thought leading her, Sif closed the small distance between them and kissed him fiercely. The growl that left his throat was pleased and his hands carded back into her hair. Never one to do something half-assed, Sif buried her own hands in his dark hair and pulled him against her.

A furious rage drove her and his mouth opened under the demand of her tongue. For months, he'd driven her crazy, made her blood boil. Her blood ran hot now, but she found the circumstances much more agreeable. There was that saying about keeping your enemies closer...

He pinned her to the wall with his long body and let his hands wander across hers. Sif quickly lifted her leg to wrap around his hip, letting the sharp heel of her shoe push into the meat of his thigh. Loki moved his lips to her throat, his hips grinding in an unsteady rhythm against her. Sif tried to move her own hips, seeking the pressure she craved but his long hands held her still.

Irritated, Sif pushed off from the wall, shoving him backwards until he fell across the white sheets of the grand bed. She wasted no time climbing astride him and tore the buttons of his white shirt open.

"Oooh, my lady," he crowed. "So aggressive."

"Shut up," she breathed against his mouth. She hated him when he spoke. Clever, cutting words. She much preferred action. So she reached for the hem of her dress, peeling it from her skin and tossing it to the floor in one fluid motion. "I have better use for your mouth."

Loki sat up suddenly, using the momentum to roll them both. Sif gasped, and his hand at her neck cradled her head to rest softly against the pillows.

"Yes. Yes, you do."

His mouth worked at her neck, sucked at her collar bones, his tongue flicked across her breasts. Long hands mapped her skin, working down her body, and his lips trailed over every inch of her exposed flesh. Sif's mind flashed back to Darcy's words about a silvertongue.

Taking ahold of raven locks, Sif pushed her hands into his hair, guiding him until he laid between her because this would be a one night stand didn't mean she wasn't getting what she wanted, needed from him. He made no protests.

Moving forward slowly, he kissed her through the fabric of her underwear. She moaned, watching his tongue press against the cotton and his lips tug and slide. She could feel the heat and wetness as he practically made love to her with his mouth, but just barely. The heels of her shoes caught against the silk of the sheets as she squirmed. Pulling hard, Sif tugged his face against her and ground her hips up, seeking more than he would give. Loki laughed.

Sitting back, he cast his own trousers and briefs aside and fished a condom out of the bedside table. Slowly he rolled it on before reaching for her panties. She lifted her hips allowing him to strip her bare.

The dark man loomed over her again, kissing her thoroughly. She wondered idly if this had been his plan. Wondered at her own predictability. But as his hand slid down her body, sparking heat against her center, she found she didn't much care. His fingers brushed feather light against her and Sif found herself tired of his taunting.

"Come on," she rasped and dug her blunt nails into the ridge of his spine in punishment.

Loki smiled down at her, raising an eyebrow. "Was there something you needed?"

"Give me what I want."

"As you wish."

He took himself into his hand, sliding his hard length against her. Slowly, he rubbed himself along her. He brushed the head of his cock against her clit and hmm-ed when she moaned. He continued the slow torture, teasing her.

"Fuck you," she gasped out. She needed more.

"Mmm," he agreed, "yes."

Pushing at her and then into her, he paused to get his bearings, one hand on her hip and the other tucked under her shoulders. Agonizingly unhurried, he moved within her. He would slow his pace to almost a standstill and then suddenly thrust with enough force to knock the breath from her lungs. Playing with her. He was so maddening. Feeling her temper rise, Sif dug the heels of her shoes into his backside. She grinned in malicious pleasure to hear him gasp.

He was always teasing her, taunting, mocking. But she'd had enough.

Surging forward, she spun them keeping her body pressed against his. She rolled her body and his groan dripped from his throat.

Sif experimented with that, rocking and grinding against him and finding that he could be so delightfully noisy. After all of the teasing, she knew he had to be as wound up as she was, and his poise was beginning to crack. She lifted herself up and rode him hard, greedily taking in his whimpers and aching cries.

She looked down on him and smiled, glad to see him come undone underneath her. He had planted his feet against the bed and was thrusting up against every roll of her hips, feral and desperate and so uncomposed. Sif reveled in it.

A hand slid down from where he cupped her breasts, fingers rubbing and circling against her clit. Her hips bucked hard and he let out a groan that was a punched out sound, deep and carnal

She gave a laugh that turned into a gasp, and let her climax crash over her.

Yes, she thought. This is what she needed. This was good. She would take this night and the release of all her pent up frustration with him and not look back. She had worked it out and now it was over. She had won. This wouldn't happen again.

She lost her train of thought and the rhythm of her hips as they stuttered with the frantic fluttering of her orgasm. Loki took the opportunity to roll her rigid form onto her back and thrust into her at a frantic pace, chasing his own release, driving her down into the mattress. The new angle of his hips made her cry out and she peaked again. She shouted wordlessly as he tucked his face against her neck and groaned out his own climax, hitched and broken, panting against her skin.

"I need you," he gasped, his hips pressing impossibly tighter until he collapsed on top of her.

Sif blinked through the haze of her pleasure trying to make sense of his words.

"What did you say?"

"I need you," he breathed, "to help me with a job."