Background: [Thor AU] Odin exiles Thor to Midgard as punishment for invading Jotunheim against his express wishes, but Loki follows Thor in self-exile out of loyalty for his brother. On Earth, the kindly Jane Foster takes them in and her research assistant Darcy Lewis proceeds to show them what Earth has to offer.

Author's notes: In the spirit of Halloween, I present my very first Loki x Darcy story! This story was inspired by mizravamp's prompt. I hope you all enjoy this!

Disclaimer: I don't own anything. All characters, settings, and proprietary language are owned by the author of the work from which this is derived.

"Dude, you seriously have to slow down." Darcy's upper lip curled in equal measures of bemusement and disgust. She couldn't believe it as Thor tore through the packages of Halloween candy they had on standby: assorted flavours of candy corn, Reese's', chocolate bars, M&Ms, marshmallows in the shape of pumpkins and ghosts, popping all their bite-size goodness into his awaiting open mouth. To think she had told Jane that they might have bought too much candy! At the rate Thor was inhaling their confectionery, there wouldn't be anything left for rats, much less trick-or-treating children.

"Lady Darcy, this is excellent nourishment!" Thor proclaimed with his voice slightly muffled from all the candy he was eating. Yet, he still flashed her a wide smile, little smudges of caramel and nougat clearly seen on his teeth as he waved a liquorice wand. It was an odd sight indeed, a man of Thor's stature dressed in jeans and a shirt that looked a tad too tight with his feet propped up against the coffee table, enjoying candy as if he were ten.

"Well, I'm glad you're enjoying it." Darcy's tone softened considerably. As much as she was annoyed that Thor was decimating her supply of candy, she couldn't help but have a soft spot for him. Hanging out with Thor was like having a gentle giant for a brother, kind and generous and incredibly chivalrous without a malicious bone in him. Thor and his brother probably didn't even have Halloween in Asgard, or wherever it was they said they were from; surely she wouldn't begrudge Thor a few pieces of candy.

Loud, high-pitched screams echoed throughout the house and then laughter, almost maniacal, filtered through. Darcy sighed as she heard Jane run out of the house and into the street, shouting apologizes along the way. This was the fifth time tonight that Loki managed to scare the bejesus out of the neighbourhood kids. God, she was going to get so many complaints from their parents in the morning! She grabbed a Twizzler from the pile of candy Thor had assembled on the coffee table and flopped down beside him on the couch.

"You were right." Darcy heard Loki say as he walked calmly into her line of sight. In the background, she heard the front door closing and Loki came to sit in the chair in front of her. He had a smug look on his face and Darcy wished she could just wipe it off. "This is an exceptional tradition you have here in Midgard."

Darcy rolled her eyes. "Only because you've set your sights on becoming the terror of the town." Though, she had to admit, he was becoming quite the attractive terror of the town. Being of leaner build, he had no trouble fitting into her brother's clothes when Jane first brought the two strangers into her house. Initially, she hadn't approved of her mentor's decision to take in two strangers she had earlier found wandering in the desert. In fact, she thought the three of them to be downright psychotic, particularly when the two men started talking about Asgard and Odin and something called mew-mew. But Jane's apartment was too small for all three of them and with Darcy's parents on an extended vacation travelling around the world and her brother living in another state, Darcy saw no harm in opening her home to them. It felt a little strange but at the same time, homely, to have all four of them living under the same roof, like some weird offshoot of the Brady Bunch family.

Though, she probably would never eye Greg Brady the way she was eyeing Loki now. His black hair was combed back to create a slick and neat 'do and perhaps it was the season, but did he looked extra spooky with his pale skin and deep green eyes? Unlike Thor, he was dressed in a more fitting green shirt (his favourite colour, apparently) and a pair of skinny jeans that seemed to elongate his already-long legs. Now, they looked like they went on for miles. She wondered, rather indecently and uncharacteristically, at how it would feel to have them wrapped around her.

"Have I upset you, mortal?" Loki's question brought Darcy out of her daydream as he looked to her with a quizzical expression. "I seem to have misunderstood your intentions."

Darcy huffed, crossing her arms across her chest. "First of all, I have a name and it's not 'mortal'." Thor snorted ungracefully beside her. He had been trying to get his brother to be nicer to their human hosts. "Secondly, yeah, you're scaring the children half to death!"

"I do not understand." Loki shook his head once, puzzlement evident in his face. "You explained this tradition to be one of mischief and fright. When you said you wanted me to partake of it, I assumed you wanted me to scare the children."

Darcy sighed and her lips pursed in slight exasperation. Yes, she had said that but how was she to know he had the ability to shapeshift his head into that of a fearsome wolf or a vampire bearing its fangs? Like any sane person, she thought he was just going to yell, "Boo!" at the children while wearing a mask.

Then again, her life hasn't been sane since the two of them dropped into it about a month ago.

"Well, yes, I did say that but I thought you'd be wearing a mask," she conceded, her harsh tone diminishing somewhat. "But I'd really appreciate it if you stopped doing that. Our children aren't quite used to your kind of magic just yet."

Loki cleared his throat and shifted uncomfortably in his seat. "Very well then…Darcy." He gave a slight nod and Darcy found it strange for her name to be on his tongue, the words so stiff and rarely used. "I shall adhere to your request, and stop scaring the little ones."

"Thank you." She gave him a small smile, hoping she hadn't offended him; but judging from the somewhat pensive look on his face, his eyes now staring into the distance, she guessed that he was probably just sullen from the fact that he couldn't scare anyone anymore. Turning her attention to Thor, her smile widened on its own accord; Thor was amusing himself by squishing gummy eyeballs between his meaty fingers.

"Well!" The front door swung open and Jane crossed the threshold, taking off her coat at the same time. "I did what I could and…" She fell silent when she saw the other three occupants had turned to face her, unaccustomed to such attention.

"Yeah?" Darcy prompted.

"They think Loki did some really cool magic tricks with a recorder for the wolf's barks, so you probably shouldn't get into any trouble." Jane came over to sit by Thor and her face paled at the sight of the amount of candy he had digested.

"Brother, look at Midgard's version of Hel!" Thor declared as he held up a few liquorice candies in the shape of skulls to Loki's scrutiny, laughing heartily. "She would not be pleased by this!"

Picking up a hairbrush from her dresser, Darcy proceeded to run it through the unruly wet tangled mess that was her hair. She had changed after her shower, trading her glow-in-the-dark witch motif shirt (worn in the spirit of Halloween) for a simple camisole and sweatpants for bed. Looking into the mirror while she tried working the brush through her hair, she struggled furtively. How silly she must look, battling her hair with a hairbrush! She probably needed to invest in some new conditioner.

A shadow crossed the light that was spilling out of the hallway and into her room, startling her momentarily, and she turned to face Loki, hairbrush still stuck in her hair. "Loki!" she exclaimed, more out of habit than of genuine surprise, because he did have a tendency to appear out of nowhere.

He cleared his throat once, and subtly tilted his head to the side. Darcy's hand flew to her head, embarrassed that she was seen in such a ridiculous state; hairbrush stuck in her hair. She grappled with the handle for a few moments before finally managing to remove it; her hair a total mess of course.

"Loki, what's up?" Darcy tried in her not-so-subtle way to change the subject, yet her hands went to smooth out her curls.

"I thought you might like to know that Thor is finally asleep, and Lady Jane thanks you for your help earlier." His demeanour was, as always, reservedly polite, with his hands behind his back, shoulders stiff, head held high. He reminded her very much of those gentlemen she had read in Jane Austen's novels.

"It's nothing." She shrugged. After Thor had finished their considerable cache of candy, Darcy thought it fun to introduce him to Bloody Mary, but only because it looked a little like blood, and it was in the spirit of Halloween. Who knew Thor would be so fascinated by the tradition that he downed enough alcohol to tranquilize an entire zoo, leaving the three of them to carry his unconscious self back to his room? Loki was the only one who barely had enough strength support Thor's weight up the flight of stairs, but Darcy felt bad, so she took over by half-dragging and half-shoving him from the landing to his bed. Already, she could feel her muscles aching.

Darcy and Loki stared at each other for a few moments before the gaze felt uncomfortable and Loki broke it to stare at a spot on the open door beside him. "Um, is there anything else?" Darcy asked.

Looking at Darcy now, Loki was bewildered at the realization that he was at a loss for words. It was not due to the fact that Darcy was beautiful, though she did have a certain kind of beauty about her, or the fact that she always seem to be able to best his brother in combat. It was her fearlessness, now and even when they first met, that impressed him. She was no one like he had ever known. She gave comebacks as good as she got them, and never once tiptoed around him. He had expected such behaviour from mortals, and even Jane seemed afraid of both Thor and himself at times, but this woman… No, Darcy Lewis was most certainly something else entirely.

He cleared his throat once more. "No, but…" he hesitated before speaking again. "I wish to apologize for my earlier behaviour. It was rude of me to not have addressed you by your name and I shouldn't have scared the children."

Darcy let out a short – almost feminine – snort, which gave rise to a small smile from Loki. "You should have just used a mask."

"I have no need for two." Loki blurted out the words before he could stop himself. Immediately, he regretted it yet before he could leave the room, Darcy walked slowly towards him, an impish look about her.

"Are you telling me you're wearing a mask now?" There was a slight quirk in her mouth as her eyes practically gleamed at the prospect of another magic trick.

In a way that Darcy didn't think possible of him, Loki sauntered past the threshold and into her room, closing the door behind him and prompting her to instead retreat further into her room. There too was a glimmer in his eye. "Would you like to see it?" he teased, with an almost-smug smile upon his face. He didn't usually behave like this. Often, he was simply too closed-off to everyone but Thor, but it seems tonight was a little different. Perhaps he was using the opportunity to scare Darcy a little, to teach her the propriety between mortals and gods. Regardless, when he stepped across the threshold, there seemed to be no going back.

The lights in Darcy's room began to flicker, an electric buzzing sound in the air. Darcy glanced around the room, almost convinced that a Weeping Angel was about to appear. When none came, and Loki maintained his strides leaving her walking further and further back towards her bed, she guessed what he was doing.

"Are you trying to scare me?" she asked somewhat assertively.

"Is it working?"

"No," came her simple answer, along with a raised eyebrow that seemed to challenge him for something more.

To Loki, it seemed Darcy had passed a test that he wasn't aware he was setting. He only played with the lights because he saw it in a movie the night before, but as they flared and he saw neither fear nor panic in her eyes, Loki knew that perhaps she would be able to handle his secret after all.

He gestured for her to sit on her bed, and as she slowly took a seat, she watched with incredulity, as Loki's human features melted away and in their place were etchings on blue skin and orange eyes.

Frost giant immediately came to her mind. In the first few days of meeting Thor and Loki, they were all Thor could talk about, especially about how they had lead to his banishment. He spoke of menacing, colossus creatures with clubs and icy stares and staring at Loki now, it was clear that he resembled them, except for their height.

Taking a seat beside her, Loki watched as Darcy's eyes widened, and waited for the revulsion and horror to take over. Yet, they did not come; instead, her jaw widened in surprise as though she had just seen a magic trick she could not comprehend.

"Does Thor know?" she whispered, unsure of how her voice might sound if it were any louder.

"No." He looked grave as he answered her. "But I think I've known for a while now, especially after what happened in Jotunheim." His eyes took on the appearance of a soldier recalling past battles. "I was always different from my family."

In that instance, Darcy felt compassion for Loki. He sounded so dejected. From what she had gathered from Thor, it seemed that the Frost Giants were their family's nemesis and for Loki to become that which his family despised? There wasn't enough comfort in the world for Darcy to offer to Loki.

"So you have blue skin and orange eyes. It's not that big of a deal. You're still like everyone else." She tried to lessen the tension, but even she could tell that it wasn't working.

"Not quite," he responded sadly. He looked down to where their hands were, just a narrow space apart, and his hand inched forward. Darcy followed his gaze and stared as his blue fingertips touched the back of her hand ever so lightly, her bottom lip quivering from the anticipation. While nothing was happening outwardly, she could feel coldness spread within her, through her veins and her muscles, the ice locking her into place. She thought it as another one of Loki's mind tricks, but when she lifted her head and her gaze locked with Loki's, she saw her shaky breaths coming out as little white puffs of steam.

Loki quickly withdrew his hand and Darcy took a few more breaths to calm herself and to regulate her body's temperature. Loki mentally chastised himself; how could he have done something so foolish and so dangerous? He could have very easily killed Darcy and for what? What had he hoped to achieve by showing her his true self? Was he hoping for sympathy, some sort of pity that would make this half-life bearable?

Holy shit, Darcy thought to herself as her body slowly recovered from the cold. At first, she imagined it all to be a trick but seeing the remorse on Loki's face, she knew that this was his way of seeking help and her heart went out to him. He probably never asked to be a Frost Giant, and she could just envision the look on Thor's face when he found out. For some strange reason, she didn't want Loki to be alone. She hadn't known him for very long, but in this moment, she felt a connection to him, something she couldn't explain but distinctly understood.

Her hand reached out to hold his, in the same gentle manner he had touched her and she smiled kindly. "Think of it this way, you get to have a killer costume for Halloween every year."