A.N.: If anyone's watched The Secret Circle, the character of Mary was inspired by Faye Chamberlain's personality, to an extent. The polished, dark attitude to cover a multitude of heartaches, the best defence a bitchy, uncaring offence. Also, Gemma from Sons of Anarchy is a big inspiration sometimes, the way Mary interacts with Derek and the others in his pack.

Since TW S3 hasn't started yet, I'm just going to come out and say, I wish Garrett Hedlund had a twin-brother so that they could play Aiden and Ethan, the twin-Alphas. Some of the back-story for Mary gives her history with them.

Summary: That's my sister Mary. She hates our parents for making us move here. She was really happy in San Francisco…after her accident, she made some new friends. A few weeks before we moved, something changed again. I'm kind of worried about her…it's not like her to be uncaring.

Jekyll and Hyde

01

Mary, Mary, Quite Contrary

Studying with Allison. Scott couldn't think of any idea more terrifying—except if he was to add a poisoned werewolf hell-bent on ripping his best-friend's throat out if Scott didn't find some magic bullet to cure him. A magic bullet that just happened to be hidden in the Argent household. The home of werewolf-hunters, one of whom had already shot Scott with a crossbow, he thought, as he tentatively stepped over the threshold.

"So…d'you want a tour?" Allison smiled, her styled curls bouncing as she danced toward the back of the house. "C'mon, I'll get some snacks. Lots of carbs, right? I heard athletes need all the carbohydrates they can to build up energy."

"Uh…whatever you have is great," Scott said.

"'Kay, but, just to warn you, my family aren't really the type to bake cookies," Allison said, with a bright smile, as Scott followed her to a wide, open kitchen.

"What do your parents do?" Scott asked.

"Well, my mom was a teacher at an all-boys' school for ages," Allison said. "Before I was born. Now she's the overseas consultant for my dad's company."

"An overseas consultant?"

"Yeah, she travels a lot. I guess I should explain," Allison said, drawing a large glass pitcher out of the enormous refrigerator, pouring two glasses of iced tea. "My dad sells guns to law-enforcement." Scott stared at her. Allison half-laughed as she pushed the glass of tea toward Scott.

"Whoa," was all he could think to say. He frowned. "Is that why you move around a lot?"

"Yeah," Allison sighed. "I mean, I don't get why we have to, I'm sure my parents could've run the business from back East."

"Is that where you're from?"

"Well, I was born in Montana," Allison said. "We've moved at least twice every year since I was born, my parents moved a lot even before."

"Jeez," Scott said, gazing at her.

"What about you?"

"Oh, I've…never been anywhere," Scott said sadly. "I've never even been out of California."

"You're lucky," Allison beamed. "I'd kill to have lived in just one place my whole life… The friendship you have with Stiles, knowing everybody in your classes…"

"But, I mean…you must've been to some amazing places," Scott pointed out.

"Yeah," Allison nodded. "But it drags after a while. Comes a point where you wanna put down roots, you know? So…are you a Doritos man or do you prefer Cheetos?"

"Either," Scott smiled. "Whichever you don't mind sharing."

"Doritos it is," Allison smiled sweetly. "Come on, I'll give you the tour… So, this is the kitchen…" She showed Scott around the house; he kept an eye out without trying to be unsubtle, for any sign of a place where someone would hide magic bullets that could kill a werewolf within forty-eight hours. The Argents' house was huge; Scott bet he could fit his own house inside it easily with room to budge. They peeked into Allison's parents' bedroom, but everything was sparse, despite the rich wallpaper, the polished furniture and lamps, it was… "My mom is minimalist," Allison explained. "We move so much, she doesn't tend to accumulate much clutter."

"How does that work for you?" Scott asked curiously.

"Well, my parents try and compensate for all the moves by giving me anything I ask for," Allison said, with a tight smile. "So I have a lot of stuff."

"Whose room is this?" Scott asked, as Allison ushered him into another bedroom. Dusky purple walls greeted him, the tangy scent of fresh paint lingering, mixing with the subtle scents of cosmetics and a rich rose perfume, candles scented with fig and rosemary; he could even smell the paints used in the numerous, staggeringly beautiful, complex and warped pieces of artwork propped against the walls. The large bed was draped in dark sheets, decadent midnight-navy, a hint of blood-red crimson, deep purple, and a shelf on one wall featured an array of jars, each containing trinkets and tiny photographs. The shelf also featured a large plastic T-Rex that doubled as a jewellery-holder, draped in dainty gold necklaces, a large, battered black box covered in decoupage and colourful puff-paint with a tiny gold clasp, a rectangular bottle of rose-red perfume and a single, plainly-framed photograph. On the shelf below, there was a collection of hardback books, cloth-bound and beautifully colourful, Scott could see they were Penguin books, and they bore the titles of the Classics.

A decadent, polished dressing-table, very old, was what drew the most attention, topped with a very large mirror, the top covered with beauty products, composition-notebooks stacked, a jar containing paint-brushes and Micron pens, cosmetics arranged neatly, and beside the dressing-table on the wall, three photographs had been transferred onto small canvases; a few novels were piled up against the side of the dressing-table. Scott caught a few of the titles: White Fang, Relic, Madame Bovary, Stardust, The Master and Margarita, Ask the Dust, Everything is Illuminated, Gravity's Rainbow, Vellum, Less Than Zero, The Book of all Hours, The Code of the Woosters, and on the top of the pile, East of Eden by John Steinbeck. A dream-catcher, full of dainty beads and texture from crochet, lace and soft feathers, tiny shells, silk flowers, braided hemp and ribbon, dangled in the corner above a squashy chair draped in a single blanket, with a small cushion and an artist's board leaning against the leg of the chair. At the end of the large bed, a leather weekender-bag sat, and in one corner of the room by a laundry-hamper, several pairs of shoes with killer heels that could easily maim someone had been tossed aside.

The whole feel he got from the room was edgier, more mature, darker than Allison. The art on the walls made the fine hairs at the back of his neck prick up, unnerved, and he dared not stare at any particular painting too long or be sucked in, drawn by the emotions the unfamiliar yet staggeringly personal scenes the paintings evoked.

Whoever lived in this room already seemed older, much more warped than Allison. He didn't know how he could tell that, just from the way a bedroom was decorated, but it was telling that, just a month after Allison's family had moved in, this room had been put together as if he had been this way for years. Someone knew how to handle the routine of moving around so much, by unpacking and settling down as quickly and fully as possible.

"What are you doing?" A voice spoke up from behind him, and Scott jumped; he hadn't heard anyone move, hadn't even sensed the girl's approach, and he doubted Allison had either, because she jumped.

An incredibly beautiful young woman with a striking heart-shaped face, high cheekbones, lovely hazel eyes and dramatic, highly-expressive eyebrows gave Scott an imperious look as she strode past them into the bedroom, taller than Scott by several inches. She had dark hair, though hers was lighter than Allison's and fell just past her shoulders in natural waves that shone beautifully, slightly mussed from the day's passing, as she dumped a mini black Dakine bag on the deep-purple comforter, stripping off a lace-sleeved black cardigan. Like Allison, she had the striking contrast of dark hair and fair skin, and despite the strength in the other girl's incredibly long legs, her visible cleavage where Allison was completely slender, her height, Scott could see the resemblance between the two girls.

"Uh…this is Scott," Allison said, biting her lip, glancing at Scott with an unreadable expression, and Scott's eyebrows rose and he flushed as the girl stared at him, right in the eyes. She had a staggeringly beautiful face. It was hard to look away from her. And she was regarding him with a slight tilt to her chin, as if she didn't quite know what to make of him yet. As she turned and pulled off a heather-green top, revealing the interesting T-bar lace back of her black bra, Scott glanced away, but not before he scented her on the air. It was a scent similar to the one he picked up from Derek…only different, somehow more feminine, and altered due to her rich rose perfume. But it was irrefutable. Allison cleared her throat. "Um…are you…what're you doing?"

"I'm out tonight, don't expect me back till late," the girl said carelessly, as she strode to her dresser, tugging open the two topmost drawers.

"You're not doing anything dangerous, are you?" Allison asked worriedly, and the other girl chuckled so low under her breath only Scott heard it as she tugged out something black; in a flick of wrist, she had her bra tumbling onto the bed, and with her back turned she tugged on a tight black sports-bra, fiddling with the clasp at the back.

"Nothing you need to worry about," she said, with a secretive, highly seductive smile at Allison over her shoulder as she took off her jewellery and placed it either on the plastic T-Rex or in the battered black box on the shelf.

"I thought you might be staying home tonight," Allison said hopefully, her cheeks a little flushed at the girl's blatant disregard for company while getting dressed, as she stripped out of a pair of tight dark jeans, revealing a hint of tiny black lace underwear, not quite a thong but not panties either, before tugging on a little pair of black running-shorts.

"Why's that?" the girl asked unconcernedly, glancing at Allison as she deftly plaited her hair away from her face, tying it in place with a thin black elastic.

"It's just…Aunt Kate's here," Allison said hesitantly. The girl stilled for a second as she reached to put the delicate gold dangle-earrings she wore into the box on the shelf, and in the mirror Scott saw her expression; wariness, anger. And her eyes glowed the same vivid electric-blue that Derek's had earlier today.

His stomach cramped. She's…

"So?"

"So…I don't know, it might be nice to have dinner together."

"Like we're a happy family?" The girl smirked, and it was an almost vicious smile that reeked of irony, a curl of her lip that was almost predatory; Allison's expression faltered, and the girl tossed her finished braid over her shoulder.

Gazing straight-on, she was very tall, with a beautiful figure, a trim waist, strong, toned and incredibly long legs, and those expressive eyebrows quirked as her smirk broadened to a smile. Scott noticed the tiny glint of a little plain silver bar at her navel. She also revealed numerous ear-piercings, those in her ear-lobes decorated with tiny ruby-red studs, the triple pinna piercings to her right ear decorated with tiny little diamonds, the single pinna piercing in her left ear with a tiny gold hoop, the tragus piercing with a tiny diamond, and a tiny opal to the second lobe piercing. She also had a tattoo on her right forearm, but Scott couldn't make it out. "I think I'll pass on the Hallmark reunion. Who's this?"

"Uh…this is Scott," Allison smiled, and Scott shook himself internally, forcing himself to focus, and to smile uneasily. She was a…here?…in this house? With her father who had shot Scott? "We're study-partners."

"Uh-huh," Allison's sister replied, with a too-knowing smirk that really seemed to lift her stunning features. Her intense hazel eyes sparkled with mischief. She stood, facing them, her elbows bent, hands on her very little waist. She was very toned, her skin a warm, healthy light-gold. And, something about her posture, the bent elbows, the slight tilt of her chin, the sparkle in her eyes, Scott knew instantly…she wasn't a threat, at least not at the moment. She was smiling, teasing, despite the edginess coming off Allison, a little uncomfortable around this other girl, unsure how to act. "Natural selection?"

"Chemistry," Allison blushed softly.

"Biology tends to follow," the other girl said, her cheekbones pronounced as she smirked indulgently. Scott found himself blushing now. He knew Stiles had given him a hard time about not taking advantage of the situation to cop a feel, but here this girl was assuming they were going to…well, follow the natural spark that had set off between Scott and Allison the first time he had seen her, with the natural next-step—the driving urge to procreate and further the species.

To get a little frisky.

"Scott," the other girl nodded, and as she stalked past, Scott tensed, his heightened senses screaming, and inhaling subtly, he felt his canines strengthen, sharpen. How he knew, he didn't understand, but when she had disappeared into the hall, after giving him another irreverent, imperious look, he confirmed what he had earlier guessed…She's a werewolf too.

But how was that possible? Derek said the Argents were werewolf-hunters… Scott had been shot by Mr Argent.

Scott tampered his senses, uncertain what to do or say, left in the girl's wake. Her beautiful face, the trimness of her waist, the toned look of her long, lightly-tanned legs, her irreverence, the anger he had felt coming off her when Allison had mentioned her Aunt Kate, it all stuck in his mind. And he noticed how Allison had responded to the other girl's blasé attitude; she looked upset, licking her lips, and turned to the hall, guiding Scott silently to her own bedroom while he heard the front-door open and close, a soft, throaty chuckle, and footsteps padding off lightly.

For some reason, the other girl was confident, unconcerned about modesty, playful and teasing, but Allison didn't know how to act around her. There was a distance between them, Scott thought. They lived under the same roof but Allison didn't know how to behave around her. Wasn't afraid of her, but wasn't particularly close with her either.

Allison's bedroom was a stark contrast to the other girl's; there were cardboard-boxes everywhere, paint swatches on the wall with wallpaper samples, a poster tacked up.

"Uh…so…who was that?" he asked, frowning, because he thought he might have seen her before.

"That was Mary," Allison smiled sadly. "My older-sister."

Scott's eyes widened, a little surprised. "I didn't even know you had a sister. Does she go to Beacon Hills High?"

"She's a senior," Allison nodded, with her sweet smile. She sighed, bouncing on her mattress. "But not by choice."

"How's that?"

"We move around a lot in our family," Allison said, with a sad smile. "But she managed to never get held back at school, until this past year. She should've graduated in June. A year ago, about four months after we moved to San Francisco…she was in this horrific car-accident. Afterward, she ran away from home for like a month. She was just really messed up for a long time."

"She was in an accident?" Scott murmured.

"Yeah," Allison nodded, her styled curls bouncing as she sighed, her features softening as she grew sad. Her eyelashes fluttered as she gave Scott a sidelong glance. "She was the only one who survived. Her boyfriend was driving; her best-friend and her boyfriend were in the back."

"Was Mary okay?" Scott asked, his mind whirring. She's a werewolf too… How is she a werewolf too, with Hunters for parents?

"She had concussion," Allison said sadly, her eyes on the carpet, faraway. "I never asked what exactly happened to her friends, but my dad said not to. He said it was…pretty horrific… She was fully-conscious when the rescue-team arrived. They air-lifted her best-friend out, but she died during surgery."

"I'm sorry," Scott said honestly, glancing at Allison. He heard a lot of horror stories from his mom; being a nurse she saw them all when kids came in after crashing their cars, messing around now they had the freedom to get around town by their own steam, and forgetting not to drink when they went to parties.

Allison was quiet for a moment, her eyes glassy, and as with Mary's anger and teasing playfulness, he could sense Allison's sadness. He bumped her gently with his arm, and she gave him a watery smile. "After the accident…Mary was a mess. I mean, I guess…we were never really very close, you'd think we would be, as the only ones we've really had growing up, but Mary's always hated…well, our family. The way we're forced to exist, but never allowed to really live. But I guess she got better, when she started hanging out with some new friends," Allison shrugged. "She was happy. Mary was always the outgoing one." Scott frowned, remembering the first day he had met Allison, he had been watching her across the hallway while she tucked things into her locker, and Lydia Martin had strutted over.

"That jacket is killer," she said casually, twiddling her long 'strawberry-blonde' hair. "Where's it from?"

"My sister worked in an amazing boutique in San Francisco," Allison answered, blushing, pleased, at the compliment.

"And you just became my best-friend," Lydia smirked, as Jackson crept up to her, stealing a deep kiss.

"She's not anymore?"

"She's just…different," Allison sighed. "Growing up the way we did, always moving, I was the one who sat at home playing Apples-to-Apples with my parents; Mary…went out and grabbed life with both hands. Even if it pissed my parents off—I think she sometimes did it, especially last year, just to piss them off."

"They don't get along?"

"Not lately," Allison sighed sadly. "I mean…Mary always hated the way our family moved around so much, we never had the chance to make lasting friendships, have boyfriends, even just put down roots for a home. But she was close with my dad when she was little, they're both kinda the same tough, warm personality." Scott smiled at the way Allison spoke about her dad, even if he had shot Scott with a crossbow. He could tell Allison really loved her father. Which sucked, as it reminded Scott of how little he even thought about his own since his mom had thrown him out. "But Mary's…rebellious. She's a lot tougher than I am, she's not afraid of upsetting our parents if it means she can actually have a life of her own."

"I think you're pretty tough, to always be able to walk into brand-new schools," Scott said honestly. The first-day jitters were bad enough for him to deal with; he couldn't imagine having to pack everything up and do it all over again, rebuild in town after town. "I don't think I've seen Mary at school, though," Scott said, frowning, scanning his memory. "She's beautiful."

"Yeah, Mary's got a face you never forget," Allison beamed. Allison's face was much squarer, but she and Mary both shared dramatic cheekbones, and the dark hair-colour; Mary just seemed to embrace the California sunshine a little more. "I don't know… A few weeks before we moved here, she just…reverted."

"What do you mean?"

"It's like…after she was in the car-accident, just before she ran away, she was…catatonic. She was really in love with her boyfriend, she had a best-friend for the first time in her life…and then they were just gone. One slip of the steering-wheel after a freak shower, all dead." Allison's eyes were glazed as she glanced at Scott; he could tell how much it upset her just thinking about her sister's accident. Did she feel that way because she had come so close to losing her sister, or because she sympathised with Mary's pain? "And they had to tell her at the hospital that her friends were all dead… Just before she ran away, she and my parents got into this huge fight, it went on for hours; my mom said it was their own fault Mary's friends died, because they'd been drinking at a party. Dad always warned us against getting in cars with people who've been drinking, you know? But Mary knew her boyfriend hadn't had a drop, that the first rain for months had made the road slick unexpectedly, it was just…"

"An accident," Scott said softly, and Allison nodded, gazing miserably at her hands, clasped in her lap.

"We didn't know it, but Mary packed a bag that night and left," Allison said, glancing up at him. "When we woke up to get ready for the day, she'd been gone for hours."

"Where'd she go?" Scott asked, his voice sounding horrified and breathless even to himself. Her boyfriend, her best-friend and the best-friend's boyfriend, all dead in one horrific accident, Scott didn't know how he would ever survive something like that. The thought of losing Stiles…

"We don't know," Allison said, and a tiny smile fluttered on her lips as she shrugged her slender shoulders. "And I doubt she'll ever tell us. Mary is a mystery." Scott smiled, chuckling softly.

"But she came back," he said, slowly twisting on Allison's desk-chair.

"Yeah, after about a month," Allison sighed. "When she came home, she was…different. Not exactly her old self…better. She was amazing." A small smile curled at the corners of Allison's lips. Scott wondered what Allison's measurement of 'amazing' was. "I mean, she's spent almost twenty years perfecting ways to evade our parents; if Mary doesn't want us to know something, we don't know about it. She's perfected secret-keeping down to an art-form. She could be a 007 for all we know."

"That would be hot," Scott said thoughtfully, and Allison giggled softly.

"We got along better last year, more than we ever have."

"Why d'you think that is?"

"I don't know… Whatever the reason, I loved it. But she was hard to keep up with. And we only hung out once or twice every other week. I would always fall asleep to her climbing out the window. I'd go downstairs for breakfast, and she'd be there already in a new outfit, still high from the night before."

"She was a party-animal?" Scott smiled.

"I guess, but it was her attitude," Allison beamed. "Then…a few weeks before we moved here…it was like she'd been in the car-accident again. Only worse…she didn't cry this time. She just…she was catatonic. She still won't speak to our parents. She hates them for making us move here." Scott remembered how that fierce, ironic smirk had imprinted on him; he remembered feeling her anger, her…grief. Allison sighed. Her features grew thoughtful, troubled.

"She liked it in San Francisco?"

"She loved it," Mary smiled. "I think of all the places we've lived, I've liked San Francisco one of the most. There was so much going on, we could get to so many places, there was always something to do, clubs and things we could join. We were there for about sixteen months, that's the longest we've ever lived anywhere. We built lives." Allison sighed heavily.

"And Beacon Hills isn't exactly San Francisco," Scott guessed. He knew Beacon Hills was a small town.

"Yeah…I'm sorry, I know you've lived here your whole life," Allison winced, but Scott smiled.

"It's okay. If you felt about San Francisco how I feel about Beacon Hills, I can understand how you and Mary feel about being ripped away from it," Scott said honestly, and Allison rewarded his thoughtful words with a bright smile.

But he couldn't help wonder…when had Mary Argent been bitten by an Alpha? Where was that Alpha now? And what had happened to her pack? How had she kept it from her parents that she was the very thing they hunted—did they even know? Did she know what they were? If she had spent all her life trying to get away from her parents, learning the best tricks to keep secrets from them, was it possible she had kept it a secret from her own family of werewolf-experts that she was one? He knew things changed with the Bite; he himself was a shining example, first-line on the Varsity lacrosse-team, a beautiful new girlfriend… Had Mary's personality changed due to her werewolf bite?

And what had happened to make her 'revert', as Allison had called it?

Yes, there were some worrisome facts about his existence as a newly-turned werewolf. He had a poisoned werewolf waiting for him to deliver some kind of magic bullet to him so he wouldn't die a horribly painful, strung-out death. But Stiles always took the bad with a pinch of salt and focused on the good. So he had to make things work with Allison despite her Hunter parents, and somehow figure out how Mary had managed to keep it from her family that she was a werewolf, so he could better keep the secret from his mom.

There was another teenage werewolf in Beacon Hills. And the first female one Scott had ever met. He wondered if Derek knew about her.

"That's why Mary's so pissed at our parents for making us move again," Allison sighed. "She's eighteen, and she's had a bunch of part-time jobs, after school, and during summers, you know…but she would've stayed in San Francisco. Our parents promised we'd graduate the same high-school was started. I don't think that Mary's really mad about the high-school thing; I think she's still angry that we had to move. When we were in San Francisco she was out every night, I guess she had a few jobs, too. She was happy, she had a lot of fun, I guess… But she doesn't seem to care, now. I'm kind of worried about her. She spends all her time out of the house, when she's here, it's to change clothes…she doesn't even eat here if she can get out of it…I'd say it's not like her, but this past year, that's exactly how she's been."

"Maybe she's just hit her limit," Scott murmured. He knew his mom had hit her limit when she threw his dad out of the house. "Maybe she's just had enough of all the moves, leaving those friends behind."

"I guess," Allison said softly. "It's just not like Mary to be uncaring."

"Have you told her you're worried?"

"She'll just laugh me off," Allison shrugged. "We were never really close… I don't know what happened to her…"

Scott couldn't stop grinning, even as he bore the magic bullet to Dr Deaton's veterinary clinic. The fact that Allison had stolen a condom from her aunt's luggage, unknowingly concealing the fact he had stolen one of the poisonous 'aconite' bullets, was something he couldn't get off his mind. A condom! He had come so close to…well, if her horrifically intimidating dad and aunt hadn't returned home from wherever they'd been out hunting werewolves, who knows what might've happened.

He almost forgot that he had met Mary Argent.

The blue-eyed female werewolf who happened to be daughter to a werewolf-hunter, the irreverent, viciously-smiling older young-woman who had been missed at the dinner-table, leading to a slight argument between Allison and her parents over them breaking their promises not to move their family while the girls were in high-school, therefore giving Mary the justification to act out, as she had, apparently, ever since the car-accident in which her boyfriend, her best-friend and her boyfriend had all died.

Allison had told Scott that her aunt moved around a lot, like they did, that she hadn't seen her in over a year and that Kate Argent used to live in Beacon Hills. She didn't know why her aunt was here, but then she didn't go out in the middle of the night hunting down werewolves, so she wouldn't have seen her aunt wield an assault-rifle against Derek.

Scott had only seen Allison's werewolf sister Mary for a brief moment, just long enough to scent the fact that she was a werewolf, and to see that her eyes had flashed electric-blue at hearing her aunt was in town. Scott's eyes turned amber; but Derek's turned blue. The Alpha's had been red the night Scott refused to kill the bus-driver. Why did Derek's and Mary Argent's eyes flash blue, while his turned amber?

From her reaction to hearing her aunt Kate was in town, Mary had to know her family were werewolf-hunters. Did she know about the Alpha in Beacon Hills? That Derek was trying to take Scott under his wing to guide him through becoming a Beta? That they were trying to find the Alpha that had killed Derek's sister, Laura, the previous Alpha?

Scott didn't understand this new werewolf world he'd been thrown into. He didn't even know werewolves had different eye-colour; or that they were deathly allergic to aconite; or that there were Hunters who liked nothing more than putting arrows and bullets into people like him.

And he was dating one's daughter.

Again, as he pedalled madly to Dr Deaton's office, Scott thought about Mary Argent. The older, stunning but indifferent female werewolf. The first Scott had ever met. And the daughter of werewolf-hunters.

He scented the air as he threw himself off his bike, glad Stiles had left the back-door unlocked; he could scent sweat and pheromones on the air, someone's panic and hesitancy, Derek's pain. The other animals in the back started acting out as they sensed him—and he could hear voices, Stiles', "Alright, here we go!"

"Stiles!" he called, careening into the surgical theatre. He did a double-take, jaw dropping; Stiles held a small electrical bone-saw to Derek's enormous bicep, paused as if waiting to pull the trigger and start sawing.

"Scott?" Stiles' pale face brightened subtly, hope and relief spreading across his features.

"What the hell are you doing?!" Scott blurted, and Scott gave him a watery smile as he set the saw down.

"Oh, you just prevented a lifetime of nightmares!" he said, looking weak-kneed as he clung to the edge of the metal table.

"Did you get it?" Derek grunted, himself looking unsteady on his feet, paler even than usual, his exposed skin covered in a fine sheen of cold sweat. Scott dug into the pocket of his jeans and passed the round to Derek, who held it in front of unfocused grey eyes as he swayed unsteadily, panting.

"What're you gonna do with it?" Stiles asked.

"I'm gonna… I'm gonna…" Derek dropped; the bullet chinked and tinkled and rolled to the—the drain beneath one of the side-cabinets.

"No! No, no, no, no!" Scott blurted, diving for the bullet as Stiles knelt over Derek, pale face concerned. As Stiles slapped Derek's face, trying to rouse him, Scott threw himself down on the floor, trying to reach his fingers to the bullet he could just glimpse, flashing in the light, just out of reach.

"Derek! Derek, come on, wake up!" Stiles blurted, as Scott frowned and gritted his teeth and tried to reach. "Scott, what the hell're we gonna do?"

"I don't know!" Scott half-shouted, fidgeting and trying to reach the bullet. "I can't reach it."

"He's not waking up! I think he's dying… I think he's dead!" Stiles shouted, utterly panicked.

"Just hold on!" Scott panted, and an idea came to him, he calmed himself down, thinking, he needed that bullet. He needed to reach that bullet. He felt the claws of his thumb and forefinger extending, and he carefully reached for both ends of the bullet. Carefully, so carefully, he lifted his fingers, and the bullet lodged between his claws, out from the drain, delight and surprise filling him as he pulled the bullet out, cradling it carefully in his palm as he jumped to his feet.

"I got it!" he grinned. "I got it!"

"Please don't kill me for this!" Stiles prayed, before punching a prone Derek in the face. "Ow! God!" As Stiles swore, shaking his hurt hand, Derek was shocked into consciousness and they quickly hoisted him off the floor.

"Give me that," he murmured, eyes hazy but already reaching toward him for the bullet. Scott handed it over, ready to go diving for it again as Derek leaned against the table, panting, and bit the end off the bullet, tapping out the contents, a powdered blue substance that he set a light to with a lighter Stiles kept in the glove-compartment of his Jeep for emergencies. With a pant, Derek blew on the sparking powder, extinguishing the flame, and, still panting, swaying on his feet, he swept the powder into his palm, took a deep breath, seemed to steel himself into doing something, and pressed the palm full of burned aconite onto the bullet-wound spreading a black infection up and down his arm. As he pressed the powder into the wound, he roared in pain, falling onto the floor with another, more bestial roar, writhing in pain on the floor. Scott watched, shocked and almost nauseated, as the wound itself…disappeared. The black infection, the bullet-wound, it all just disappeared in a tiny wisp of bluish smoke.

"That…was…awesome!" Stiles declared. "Yes!"

"Are you okay?" Scott asked dubiously, eyeing Derek, as he climbed off the floor, already going for the elastic blue tourniquet he had borrowed from Dr Deaton's medical supplies.

"Except for the agonising pain?" Derek snapped back, glaring at him.

"Guessing the ability to use sarcasm is a good sign of health," Stiles remarked tartly. Derek glowered at him.

"Okay, we saved your life—" Scott blurted, on edge and a little stunned by what he'd just seen. "—which means you're gonna leave us alone! You got that? And if you don't, I'm gonna go back to Allison's, maybe her sister can teach me—"

"You're gonna trust them?"

"Her sister Mary is a werewolf."

"What?" Stiles blurted a laugh.

"That's not possible," Derek scowled. He stared at Scott, luminous grey eyes searching his face for a tell to let him know Scott was lying. Scott stared back at Derek. He hadn't known about Mary Argent.

"You didn't know about her? I was just at the Argent house, I met Allison's older-sister Mary," Scott explained, a little bemused, staring wide-eyed at Derek. "I don't know how I knew it, but the second I picked up her scent I knew she was a werewolf."

Derek stared back at him, as if Scott had just told him something…completely unbelievable.

"How can the Argents have a daughter who's a werewolf?" he murmured.

"How could you have not told me that Allison has an older-sister who's a female-freaking-werewolf?" Stiles gaped at Scott, appalled and apparently delighted.

"Do the Argents know?" Derek demanded. "And are you sure?"

"I don't think so," Scott shrugged. "Allison doesn't know anything about her family being Hunters, she just thinks her dad sells firearms to the cops. She says her sister was in some car-accident a year ago, and she ran away a few weeks after that. And a few weeks before her family moved here, Mary became really depressed and withdrawn. And when Allison mentioned to her sister that their aunt Kate is here in Beacon Hills, I saw Mary's eyes flash bright blue in the mirror, just like yours do."

Derek's eyebrows flew, his eyes sharpening, the cogs whirring in his brain, and Scott wondered again what it meant, that Mary Argent's eyes had shone blue.

He sighed softly. "Allison says her sister's spent her whole life trying to get away from their parents; after this car-accident she was in a year ago, she ran away for over a month just after it happened; they still don't know what she got up to."

"She probably went searching for her pack," Derek said softly, his eyes shining brightly. He glanced up at Scott. "You're sure none of the Argents realise what she is?"

"I guess not, I mean, I don't know, I only met her while she was getting undressed—"

"Whoa, hold on there a second—you met her while she was getting undressed?"

"She looked like she was heading out, sports-bra, running-shorts," Scott shrugged.

"How'd she look?"

"Toned. And curvy. Trust me, when you've seen her, you won't forget her. Her legs are incredible," Scott remarked, with a subtle smile, and a shrug. "Black lace panties."

"You saw her—"

"Stiles!" Derek barked, and he jumped; they both turned wide eyes onto Derek. "If she's a werewolf, she has been for a while, especially if she can pull the wool over her parents' eyes, and she'll know exactly what you are."

"So, what does that mean?"

Derek sighed heavily. "I don't know. And I don't like that I don't know."

"Didn't you know another werewolf was in town?"

"It's not like we meet at Starbucks every Sunday morning for coffee," Derek remarked tartly. "Okay, our lifestyles are private, they have to be. Packs form and they stick together, in defined territories, with clear hierarchies. If she's alone, she's an Omega."

"What does that mean?"

"Either she never found her pack and she learned to control herself on a full-moon, alone, or she was part of a pack but she's been kicked out," Derek said quietly, heaviness lacing his tone. "Chances are if she's still living with her parents, she might've had no choice in leaving her pack."

"Allison said just before her family moved, her sister changed again, like, to how she was after the accident," Scott remembered. "She called her 'catatonic'. I could… I could sense her grief."

"She might've been part of a pack that's been wiped out. With parents who're Hunters, it's possible that's the case," Derek sighed, and he looked troubled. He scrunched up his face tiredly, traipsing over to the sink to wash his face before drying it off, pulling his t-shirt on. "There's also something it would be incredibly dangerous for the both of us not to consider."

"What?"

"That her parents know she's a werewolf and are using her to infiltrate and destroy packs," Derek said heavily. Scott stared at him, frowning, trying to picture the girl he'd just met, for a brief few minutes, working her way into a pack only to see them shot up and cut in half by her parents.

"I don't know," he said softly. "Allison said Mary doesn't talk to their parents, barely talks to Allison. They don't know what she's been up to the last year, she's been…rebellious."

"I am liking this girl the more you tell me about her," Stiles sighed, half-grinning.

"We need to find out what's going on with her," Derek said sternly.

"How?"

"I'll head over to her house," Derek said, and Scott's eyes widened. "If I can catch her scent, I can track her."

"Panty-raid?" Stiles quipped.

A.N.: Please review.