A/N: Hi, it's been a long time but here I am. I've hit somewhat of a writer's block recently and I'm sticking with that excuse in case you all hate this chapter! Let me know how you feel about it and what you would like to see :)

—

There was something unsettling about not being around Casey.

In just a few short months he had gotten used to her constant presence, subtly following him around, observing him with her attentive eyes. If she was trying to embody his long-absent conscience, she was definitely succeeding, because no matter how hard Derek tried to go against her advice or her judgement, she was already embedded in his mind. Some times he would catch himself questioning his own decisions, or rethinking arguments, in a way he had never done before. It was all her fault. Her perfectionism was apparently contagious, and even without her around, she still played a part in reviving his morals. Suppressing the 'Casey' nagging side of his brain was actually really fucking hard.

At least she wasn't always that over-achieving know-it-all. Her moral compass had gotten severely off-track since meeting Derek, and if she had tainted his thoughts and way of being, Derek could only hope he had made much of the same impact on her. Unfortunately though, he couldn't take all the credit for her Derek like behaviors: Casey was a natural. Her put-together front was just that, because she could be just as reckless and vicious as him, you just needed to know what buttons to push.

And Derek knew; that's what made it so fun.

Now being without her was awkward, like trying to walk around with your hands tied. He felt like he was on the lookout for something at all times. There was this unnerving sensation that their war had merely been paused, and he felt as though it would restart every time they crossed paths. The tension was palpable; he could smell it just like you could smell a thunderstorm right before its first rumble.

Their last conversation replayed itself mercilessly inside Derek's mind, bringing him back to the exact moment their performances started. They didn't know each other.

The new girl? Blue eyes? No, I don't know her, he would have to say, half wishing it was actually true.

It was stupid how hard he was fighting to keep his character intact. It should be easier to know who he was without her, those seventeen years should have taught him something. He was Derek, the reckless, cool fucker most guys wanted to be when they didn't know themselves well enough. He was DE-REK, the cruel step-brother that suburban princesses did not ask for. He was Derek, disappointing son and step-son, with edges yet to be polished.

He was his own person, sure, but the weight of other's expectations over his life often had him wondering just who the hell that was. Truthfully, he enjoyed the attention. Not in the same ways Casey did, he hardly ever sought out anyone's approval, but simply because it was fun. Some times he didn't even want to be the leader, it just happened. He was a bad influence, as some may suggest, yet someone people like to be around. His step-enemy was the obvious exception to the rule, as she often reminded him that she would rather be quarantined than be in the same space as him. It was bullshit though, Derek didn't doubt it, because even after begging to be left alone, she always seemed to end up on the other side of his bedroom. Maybe Casey didn't crave his attention, maybe she wasn't longing for his company, but she enjoyed it. So did he, at least it was never boring to be around her. And that seemed to be enough then.

But now everything was fucking boring.

Casey would always sit on the first row, but never in the center, since that would make her eagerness to learn way too obvious. She'd curl her hair around her fingers, nibble on her pencil with her glossy lips, and she would always mumble the answers of every question, even when she didn't raise her hand. Her legs always dangled underneath her table, and some times her restlessness would guide her feet to rapidly tap on the wooden floor, a sound all too familiar in Derek's ears. He hated how much he observed her. He knew he kept it cool and discrete, but he was still paranoid that someone would notice the way he looked at her, or even worse, that someone would realize they knew each other.

If that had already happened, he didn't know of it. Until then no one had suspected it, even if his new group of guys would often talk about Casey. Half of the comments were about how obsessive she was with her studies, and the other half were obscene half-hearted 'compliments': Her fucking legs... She definitely has blowjob eyes… I wanna rip her skirt off of her… I would show her something much interesting than those fucking books of hers.

In times like that, all Derek could do was remain silent. He had already spent months quieting down his own slightly dirty thoughts about her, and ignoring the twitch in his dick whenever she walked around the house with only her towel wrapped tightly around her. He refused to agree with the guys, not out loud at least, because besides being his step-sister, Casey hated him. And he hated her too, not only because he was supposed to, but also because he absolutely had to- otherwise things wouldn't make sense. This was their normal, and Derek wouldn't dare to change it.

Still, Casey was doing much better than what he had anticipated. He half expected her to give up before their first two weeks there, by losing her temper and cussing him out in front of everyone over some dumb shit. But now almost a month had passed and Casey was still ignoring him with the exact same ease- which bothered Derek to no end. Was it really that easy for her to pretend like he didn't exist? If so, why wasn't it as effortless for him?

—

Casey was bored.

She'd been bored since the end of her first week on campus, which was around the same time the magic of the boarding school decided to fade away.

Her room was the last one on her floor. It was after the leisure spaces and shared kitchen, at the end of the long hallway with all the bedrooms. It felt more like a closet than a room, even if Mrs. Hastings had guaranteed her they would make adjustments throughout the school year. The walls were a dull white, and the fluorescent yellow light hanging from the ceiling gave her headaches if she stared into it for too long. Her bed was comfortable enough, thankfully she wasn't one of those people who could only sleep in their own bed, but it wasn't any more spacious than the one back in London. She had only one shelf nailed to the wall, which she sincerely hoped wouldn't collapse under the weight of her books since it didn't look all that secure. The two posters she brought from home were also hanging proudly above her bed, as a sad attempt to brighten up her room. The closet they provided her was absolutely tiny, which made Casey thankful that her mother nagged her to leave most of her clothes behind.

The only thing she really enjoyed about that room was the large, and only, window in front of her bed. The faint orange sunlight reflected all around her room right at dawn, Casey's favourite time of the day and her view wasn't all that bad either: she could see the back of the campus, where a grand grass field stood, possibly for soccer or lacrosse.

Her living situation was the least of her concerns though. If she had heard correctly, there would be a Halloween party that Friday night. As if that wasn't stressful enough, she'd have to wear a 'costume' as well. By the sounds of it, and by the encouraging words of her new friends, it was a party that Casey just couldn't miss, even if she wanted to with a burning passion. With her reputation on the line (the word had already spread that she was a keener), Casey realized she really couldn't miss this party, or rather the opportunity to show she knew how to have fun too.

Let it be clear that a part of her actually wanted to go, but that the anxiety-driven side of her was screaming louder for her to stay home.

The left-over panic from the last time she attended a party was eating away at her. The horrible way it ended was the exact she was now in that school and in that situation. If something were to go wrong this time too, what would be the next punishment? Being expelled? Prison?

Okay, maybe she really did need to relax. Maybe it would even be fun, even if didn't have the highest of hopes for it...

Because Derek would be there, of course he would, life simply wasn't that kind. The image of him there made her skin crawl. He would get in trouble, of course, and she'd have to help him fix it. She was counting on it, Derek would always stir up trouble as if his life depended on it. It was overwhelming but something she had grown accustomed to.

And maybe this time she wouldn't be there for him, which was a thought a that made her as uncomfortable as it made her feel relieved.

In all honesty, it was weird to pretend she didn't know Derek, even if she had long dreamed of it. This was her chance to un-meet him and press reset on her life, yet it didn't taste nearly as sweet as Casey once pictured it. Derek didn't seem completely satisfied with their new reality either, given his desperate and obvious attempts to get her attention. He always stared at her and her friends, with those shark eyes of his, and it made her really uncomfortable. Her friends, on the other hand, would get giggly just by sensing his presence. Not all of them, but just enough to inflate his already monumental ego.

Casey still refused to play his games, even if it made her blood boil when he talked up all of her friends except her, or when he would say stupid shit in class just to get her to turn around and roll her eyes at him. If it bothered her, she barely let it show, because there was no way she would ever give Derek the satisfaction of getting under her skin. This way was more convenient anyway, at least no one would find out the abnormal relationship and past they shared, which in itself was already a huge relief.

Of course there were moments when Casey really thought she would cave in and ruin her act, especially when those same girls commented on how hot and cool Derek was. Really? Casey would say, scrunching her nose in slight disgust- Definitely, they all agreed in-between giggles, something that always made her think back on Emily and on how well she would fit in there. At times like those, all Casey could do was shut up before she completely crumbled down and told those girls what Derek really was like: a problematic, hygiene-troubled young man, that never flushed the toilet and whose room hadn't been cleaned since 2003.

Really, what the fuck do they see in Derek anyway?

—

The ultimate point was that she was stressed. Stressed about the party, stressed about having to share a space with Derek once again, and absolutely fucking stressed about the outfit her friend was insisting on her to wear.

"You're Catwoman!" Lindsay laughed, watching Casey stare confusingly at the clothes. "Or a sexy black cat if you'd prefer."

I'd prefer to not wear it, she thought, embarrassed.

"Thanks," Casey nodded awkwardly, trying to make sense of how that miniature of a skirt would ever reach her knees "I'll try it on."

Before locking herself in her room, Lindsay touched her shoulder "There's a mask too!"

Casey felt a roaring scream make its way up her throat, but she swallowed it back down just in time. She forced a smile before closing the door on her eager friend. Just the thought of her wearing that, in front of people, made her want to laugh. Or cry. Or both. It was ridiculous, but apparently she wasn't the only one insecure about it. All of the girls on her floor were dressed somewhat racy, and even though Casey did not consider herself a prude, she felt sweaty just thinking about putting it on. Given the short time they had to look for an actual costume, and the effervescent desire to wear something besides the school uniform, all the girls in her class had put on half-hearted attempts at an outfit. None of them had put any real pressure on Casey to wear the all-black clothes that she was now holding, but she felt obligated to, since they had been that kind as to offer it to her. Being the new girl would always be difficult, but they really were making it much easier for her to fit in.

Somehow Casey did feel a little better when she finally tried it on, despite the fact that the girl on the reflection seemed to be mocking her.

The black top fit her rather well, it was (thankfully) long-sleeved and tied at the front with a knot positioned a little further down than what Casey expected. Nonetheless, she looked good. Sure, her boobs seemed to be staring at her, begging to be noticed, but other that, she felt good. The skirt was still a no-go though. Black jeans would have to suffice, it was fucking nearly November in Canada after all, and Casey did not intend to suffer from hypothermia. And the norm for the event seemed to just be to wear something that would cheat the school's dress code, which Casey was more than okay with.

The mask sitting on top of her bed was calling out to her too, and she tried it on with a sly smile. It covered most of her face, from around her eyes to the tip of her nose, and Casey suspected it was the only official part of that costume. Did she truly feel Catwoman? Or anything remotely close to a sexy cat? No, but she was already pretending so much those days, surely she could also pretend that she was fucking hot and ready for a good time. Hopefully no one would immediately recognize her either.

—

Derek was skeptical when his friends mentioned a Halloween party, mostly because a party at a boarding school full of minors seemed, at the very least, fucking lame. But when the rumor reached him that people would sneak alcohol in, as they did every year apparently, Derek was suddenly hopeful. He desperately needed to relax and let loose, and that night felt like the ideal time to do so. Especially since at this party nothing could go wrong like at the last one. The absence of responsibility pleased him endlessly and without his nagging conscience around, he could truly be himself (whoever that was).

Because of course Casey wouldn't be there, life simply wasn't that kind. He'd adore to see her though, he'd pay good money to have her there, awkwardly tip-toeing around, judging all those she deemed beneath her- because that's what she did. He must have been dreaming the moment Casey admitted to him that she did have fun that night, when they were locked away in the bathroom. It was so out of character for her to be irresponsible and chilled, so Derek knew he must have dreamt it.

Being at the school felt more or less the same, they were also locked away from everybody else, forced to be together, even if they tried so hard to pretend they weren't. Still, that night had maybe opened his eyes to the possibility that Casey could actually be fun, and he wasn't letting go of the idea that there could a sequel.

He had put on a lame Devil costume, wearing all red clothes with horns and one of those typical sticks to match. If George could see him then, he sure would have a good laugh. He'd been telling his son he was the devil ever since Derek was little, repeating the story of how he managed to scare away all his baby-sitters just so he could watch tv into the late night with Edwin. Those times had come and gone, but Derek couldn't be sure if he had grown out of that phase or grown into that costume. And tonight, he wouldn't care either.

"Venturi!" Someone called out from behind Derek, as soon as he walked into the school's so-called 'event building'. "You came!"

"How could I ever miss this lame party?" He huffed, throwing in a thin laugh for good measure "So, this is the rather charming event building?"

Derek looked around, not sure if he was disappointed or amused at the situation. He was standing at the vast hallway that must lead to the actual site of the party, given that he could already hear the faint hum of rock music and muffled conversations. Fake spider webs hung from the ceiling, along with some Derek admitted must be real, and small pumpkins were planted in every corner. It all looked a little corny, especially with what must have been a teacher dressed as a vampire guarding the door, but the promises of alcohol and good times were enough to shut Derek up.

The guy next to him, Parker, was dressed as a hockey player. How creative of him, Derek thought, since he was the actual hockey team captain. Looking at his friend dressed like that made him slightly jealous since he was the only team captain back home, and now he wasn't even in the team. The truth was that he missed hockey enough to have the urge to steal Parker's very real hockey equipment and steal his spot as team captain.

"Let's meet up with the guys inside and raise a drink to Satan himself." Parker said, bringing Derek back to reality.

"Please. Let's." He begged, licking his lips in anticipation.

Inside the event room, things looked pretty much the same. Dimmed lights with a few neon tones, a disco ball that appeared to be at least 30 years old, and several tables with food and uninteresting drinks. There was a huge white wall at the end of the room, where old horror movie clips were being projected. It was subtle but somewhat charming, and even with his expectations set quite low, Derek was still a little impressed. The room gave off very distinct old gym vibes, with smooth plastered floors that felt eerily familiar, like some old memory Derek couldn't actually reach. There were people dancing at the center, some of them severely uncoordinated, but most of the groups were hanging around on the sides. It seemed like every class from the 10th to 12th grade was there, which made the space look quite full. Most people were wearing costumes, but only a few were actually thought-out and elaborate, since most of them just appeared to be last minute choices, much like Derek's own costume. The girls, who Derek eyed attentively, were mostly wearing regular clothes, with a few kitty ears, masks and some times even a tail. They looked good, so good that he didn't even realize the mumbled hmmm that had escaped his lips.

"There's Kingston and Clark!" Parker warned, elbowing Derek to make sure he followed him through the crowd.

"Hey, guys." Derek greeted, bumping fists with the two lanky guys in front of him. They were both seniors and both hockey players, which is why Derek tried so hard to be on good terms with them.

Kingston was also wearing his normal hockey equipment, with the big twist that he drew a gapping bleeding bullet hole in his forehead, and some blood around his mouth. Clark seemed to have completely missed the memo, or rather ignored it, because he was wearing his normal clothes- jeans and a white shirt tucked inside a big, leather jacket that looked like it had belonged to his father. Thankfully, under said worn out biker jacket, were hidden flasks and some cans of beers. Derek decided it was best not to know what was inside the flasks until he had drunken it.

"A toast," Clark proposed, passing around the flasks discretely between them "To us."

"To raising Hell tonight, and always." Parker added, directing his focus specifically at Derek, who gave him in return the dirtiest, slyest smile he could phantom.

Derek lifted the flask so he could take a sip. Whatever was in it warmed his lips before severely burning the back of his mouth and the whole way down his throat. It tasted cheap, like some imitation of real alcohol, but Derek savored it in contentment anyway. How often do you get to drink something besides regular beer at a private boarding school? So rarely that Derek felt that he had become unskilled when dealing with strong drinks. He felt like a 14 year old who had just stolen dad's beers for the first time. He traded off his flask for the others, trying out every type of liquid it held until all the tastes began to melt together and it didn't burn anymore.

After an hour, he was drunk.

He suspected it hit him sooner than that, when he laughed at some kid wearing a sheet with holes cut out who told him a knock-knock joke. Or when a girl disguised as an angel asked him to dance, and he ended up making a complete fool of himself on the dance floor. Honestly, there were only a few things going through his mind: 1) I hope I don't puke 2) I knew Casey wouldn't be here 3) Why isn't Casey here?

What he didn't know yet was that not only was she there, but she was also seeing everything that he was doing with a big, stupid grin on her face. Casey didn't think she had ever seen Derek drunk, since whenever he drank it was always at other people's parties and houses (to which Casey was never invited), and never at their own. To put it simply, this was as entertaining for Casey as watching a newborn deer trying to walk for the first time. His movements were sloppy, his dance moves were atrocious and his hair stood untamed, slightly damp from his own sweat. She was sure he hadn't seen her, he probably couldn't even recognize her with her wearing mask, so it made it all the more tempting to continue watching him anonymously.

"Is that Derek?" Matilda asked, squinting her eyes at the dance floor confirm her theory "Oh. My. God."

"Yes, it is!" Casey laughed, amused that the topic of conversation wasn't just about how hot he was.

"He looks ridiculous." Lindsay added, shaking her head tenderly "It's so cute."

Scratch that.

Well, that's one word for it. The words pathetic, foolish and even disgusting also came to mind, but Casey settled for silence and a prominent frown. Casey suddenly worried he was somehow hearing her thoughts, because he had just abandoned his dance partner and was now headed directly towards her. She silently prayed to all gods for him to not recognize her, but the damage seemed to be done. He was edging even closer now, stumbling a bit in his march towards her. He had this unreadable expression imprinted on his face that sent Casey into full panic mode. Unfortunately, she had never been the best in dealing with such impromptu situations, so she decided to avoid it altogether. She managed to mutter that she needed to excuse herself to the bathroom before walking away in a hurry.

"Hello ladies." Derek's voice seemed distant now, as she made her way across the room, hiding away in a dim-lit corner.

She was scared he was drunk enough to say something he shouldn't, like calling her sis, or Spacey, or any other stupid nickname that only people who know each other have. Casey thought she was safe enough there, hidden away behind a dusty unused table, but as a stumbling shadow made it's way over to her, she had to reconsider her options. It was definitely Derek, his devil horns had made his silhouette quite obvious. Casey was cornered. He was coming at her fast, straightening out his posture as he walked, and there was really nowhere to escape to.

"Catwoman." Derek mumbled in complete seriousness, stopping only when he was inches away from her. "What the hell are you doing here?"

"I could ask you the same thing," Casey replied, attempting to sound unimpressed. "Shouldn't you be with your buddies? Or at a reunion with Alcoholic anonymous?"

"I thought I would come and say hi." He was smiling now, and it seemed that a small laugh was caught in his throat.

It was the first time they were talking since God knows when, so was it wrong that Casey was enjoying it just a little bit? It would only be wrong to show it.

"And I thought we weren't supposed to talk to each other." Casey scoffed, folding her arms across her slightly bare chest "So why are you here?"

"No, no, you're all confused." Derek shook his head, running his hand through his messy nest of hair "I'm ignoring my step-sister, Casey. But she clearly isn't here right now, because she'd never attend a party like this, especially wearing that…"

"Shut up, Derek." She hissed. Oh, a part of her definitely missed this.

"Sorry, I'm here on a mission." Derek pointed to the plastic horns sticking out of his tangled hair "To raise Hell."

"Actually, I've never seen you wear a more fitting costume. Did you grow the horns yourself?"

"So clever." He admmited "You almost sounded like Casey there for a minute."

"How did you know it was me anyway?"

"Please, Case." His smile was wider and relaxed, which made Casey want to laugh a little too. "I could recognize those baby blues anywhere."

Her heart raced slightly at that observation, but she ignored it. It was simply a manifestation of the tension irradiating from their encounter.

"You were pretty discrete out there too, you know?" She mocked, biting her tongue "Barely anyone was paying attention to the demon making a fool of himself on the dance floor."

"At least someone asked me to dance." His tone was mocking, but the comment stung more than Casey was willing to admit "At least someone noticed me."

Ouch.

Casey stared at him for a moment. She noticed his left hand resting on his accessory stick, which felt more like a cane by the way Derek was depending on it to walk, and the way his eyes looked glazed as if he was in a blissful daze. His lips were shiny, probably coated with leftover alcohol that Casey suddenly wished she could drink too. He smelled absolutely ridiculous, like cheap vodka and Halloween candy that had melted together- it was intoxicating. He was so fucking… Sigh.

Casey paused to think about her next move for a few more seconds, before removing her mask completely, letting the elastic dangle in her hands.

"Well," She cleared her throat, attempting to swallow the knot that had settled in the back of her throat "Masks off, Derek."

And with that, she gracefully removed his plastic horns as well, as a confused Derek stared back at her.

"Now I'm back to being Casey and you're back to being just slightly demonic Derek. Which means that now we can go back to ignoring each other." Casey seriously doubted she had ever acted so cold towards him. All she could feel was pure resentment. "I don't know you, you don't know me."

She didn't wait for Derek to reply, and given his stunned expression, she doubted he would. Casey simply reached out to grab Derek's arm, lifting his open palm towards her, and placed both his horns and her mask on it. And without any other words, she left him there, still stunned and still way too drunk to deal with it.

Her stomach turned as she made her way back to her room. Moments of warmth and casual happiness are not a relationship make, not that she was sure she could call that thing she had with Derek a relationship, it was more like a relation between two individuals who despised each other. Because they did, and maybe they always would. That moment had been more than enough to ground her back to the unwelcoming reality: she would never get along with Derek and that really pissed her off.

Why did he have to make everything so complicated?