Derek sat waiting on the living room couch of the Stilinski home, rather impatiently, he might add, for a wild Stiles to appear. He kept twirling his phone absentmindedly for something to do, but he was ready to go. He had finally been invited to the annual 'Break into Beacon Hills High and Exchange Presents' soirée, and he wouldn't deny he was a little excited to attend. Granted, he hadn't actually known about it until a few months ago when he'd been thrust directly into Stiles and Scott's path when the latter had been bitten by a werewolf of unknown origins, but he was excited nonetheless. And he wouldn't deny that he felt pretty damn cool to be included.

Honestly, Derek found the whole thing adorable.

There was a routine too. They broke into the library, exchanged presents in a game of Dirty Santa, drank enough hot chocolate to throw up, according to Stiles, complete with mini marshmallows, and played some Truth or Dare until the wee hours of the morning.

And the mini marshmallows thing Derek only knew about because Stiles had demanded them. And, of course, that meant Derek had been forced to go another town over to get them since every place here was sold out. And yes, it had to be mini marshmallows. Derek had asked. Multiple times. Stiles would not be swayed, damnit.

Noah walked into the room suddenly and motioned for him to follow. "Can you come in here for a second?"

Derek nodded, even though Noah couldn't see as his back was already turned, and jumped right up. When they were both in the kitchen, Noah crossed his arms menacingly, lowering his voice even further.

"I turned off the alarm, but can you please make sure they don't burn the place down? I know they got some fondue thing for this year and it makes me nervous. I know it's small, but it's technically an open flame. Something I rarely allow Stiles around."

"What?"

"The library," Noah elaborated. "Can you just keep an eye on them? I know you're not that much older, and you're not their babysitter, but it would make me feel better."

"I, uh... sure?"

Noah laughed, shaking his head as he let one of his arms fall. "Do you really think that I didn't know that my son and his idiot friends sneak into the library of their school every winter break and exchange presents?"

Derek shook his own head, realizing very quickly how foolish it was to believe that exact thing, despite the fact that Stiles had insisted it was the truth. No way his dad hadn't always known. The man had raised Stiles. Hell, if he hadn't been paying pretty close attention all his life, Stiles would probably be in jail or dead at this point.

"Yeah, I got it," Derek agreed with a light chuckle.

"Good. We're going out."

Derek's eyebrows perked in surprise when he noticed Melissa McCall standing a few feet away in the formal dining room no one ever used. "You're both going out. Like... together?"

God, this was not Derek's business. But clearly Stiles had rubbed off on him or something.

"Yes, on a date," Noah answered decisively. "Hence why I'm asking you to keep an eye on them. I'd like very much not to be interrupted."

"Ah."

"A date?" Stiles screeched from somewhere upstairs, causing Derek to roll his eyes. "You guys have a date? Like a date date? Where?"

Derek said his name like a warning next. Which it usually was.

"Stiles. Time to go."

"No," Stiles whined. "I wanna hear more about this date."

"Stiles, seriously," Derek tried again, ushering him back toward the front of the house just as he rounded the corner into the kitchen with them. "We gotta get to the bowling alley before all the good lanes are taken. You don't want to have to listen to Lydia complain about the one with the broken screen, right?"

"The bowling alley?" Derek gave him a pointed look. "Right, yeah, but..."

"Nope. Going. Now. See you later, Sheriff."

"You boys have fun," Noah called after them.

As Derek removed Stiles from the house bodily, shutting the door behind them both, he began to visibly pout.

"Dude. Not cool. Just because you're bigger than me with all your werewolf muscles doesn't mean you can manhandle me, okay?"

"You like it," Derek teased with a wink.

Stiles growled as Derek hopped down the steps and made his way to Roscoe, which he knew to be loaded down with presents for the whole Scooby Gang, even though the rules were to only bring one. Well, okay, he tried to growl. But it was way too cute to be sinister. Like a little kitten trying to be a lion.

Not that he'd ever tell Stiles that.

"Calm down, all right? The whole point of this ridiculous tradition is to try and hang onto what little bit of childhood any of us has left, right?" Derek asked him over the hood of the Jeep. "I know what it does to a person to grow up too fast. I don't want that for you."

Now it was time for Stiles to roll his eyes as he automatically climbed into the passenger seat of his own car. Something that wouldn't have happened at all in the beginning, but had become more and more commonplace lately.

"Sourwolf, listen," he began as Derek got in as well, "my mom died when I was young too, remember? Younger than you when yours did. It's too late for me. Probably too late for any of us, at this point, but you're right. I want hot chocolate and presents and to act like a dumb kid whose whole world isn't on fire for one fucking night. Did you get the mini marshmallows?"

Derek laughed quietly. It never ceased to make him smile that Stiles could say all that in a single breath. "Did you just say I was right?" he countered, putting on his seatbelt.

"Oh, shut up," Stiles grumbled, making Derek laugh louder as he pulled away from the curb.

Of course, it faded quickly when an errant thought struck Derek like lightning. They had both lost their mothers. They both knew the intense pain that came from that very specific trauma. And since Derek had tried wracking his brain for weeks now trying to figure out whatever this odd connection was that they shared, he wanted to believe this was it. That he'd solved it.

And also, he wished that wasn't the case for either of them.

But he forced the very same thought from his mind in the next second, relaxing his body muscle by muscle as he drove through the streets of their town at a leisurely pace, enjoying the silence that so rarely accompanied Stiles. And he was bolstered by the thought that for the first time in what felt like forever, his entire pack, sans Peter, obviously, would be in one place. He could account for all of them. He would know, beyond a shadow of a doubt, that they were all safe. Something pretty damn rare these days.

As soon as they pulled into the spot in the otherwise empty parking lot next to Scott and Allison, Stiles took off, leaving Derek to fend for himself as he made his way to the back of the Jeep to get all the supplies.

"Don't worry, Stiles," Derek muttered under his breath. "I got it. I'll just take everything in by myself. No problem."

Someone chuckled behind him and he turned in time to see Isaac standing there with an amused look on his face. And Derek couldn't help the blush that spread at the idea of getting caught complaining about Stiles.

"Here," Isaac offered, holding out his arms.

And then Jackson and Lydia pulled up next, copying Isaac and helping Derek without complaint and chatting happily all the way inside.

By the time they joined the other three, they'd managed to make room for the festivities. All the usual tables lined up in the middle of the library that people often used to read and study were pushed to the sides. Three had been separated out, though. One for presents. One for food. One just for hot chocolate, according to Stiles.

The rest were far away from the huge, fake Christmas tree whose lights had mysteriously found themselves back on despite the fact that Derek knew the librarians had turned them off and unplugged them before leaving for their two-week vacation.

Derek smiled. Stiles returned it. And it was strange. For once, Derek knew everything was fine. Just as it should be. Everyone was here, enjoying themselves like normal teenagers. Even Derek, who honestly couldn't remember most days what that had ever been like, was comfortable in his ugly Christmas sweater. The very one Stiles had picked out and demanded he wear.

It dawned on Derek that Stiles was doing a lot of demanding lately. And it should probably bother him a little. But it didn't at all. Stiles offered Derek peace in a way nothing else had lately. And no, he didn't care to peel back the layers of their interactions either. It worked. Derek was less grumpy. Stiles was happier. Everyone else fell in line.

But there was still something missing. Peter.

And before he had time to go down that fucking rabbit hole, the door behind Derek opened and Stiles' smile turned to more of a grimace and then an outright frown, meaning that Derek knew who had shown up.

Kate.

Kate, who had basically taken on the role of pack mom without being asked. Kate, who seemed to love and want to protect them all as fiercely as he did. Kate, who hadn't actually done anything wrong, as far as he knew. But just as much as he didn't want to uncover the source of that peace Stiles brought him, he didn't want to deal with whatever was going on between Stiles and Kate either. Derek just chose to ignore it. Especially since Stiles was content to do the same.

Kate came over without prompting and Derek tore his eyes from Stiles' as she tucked herself under his arm and then made her way to the nearest table, helping Allison and Lydia finish setting up.

But it wasn't long before Derek was watching Stiles again, and he noticed all the minute shifts. Like the way Stiles' eyes narrowed for a second and then he turned back to Scott so he could do what he did best when Kate was around. Pretend she was goddamn invisible.

After all the food was laid out, and Stiles' hot chocolate station was to his liking, they began their game of Dirty Santa. And they fought over each and every present that was unwrapped like it was a rare collectible and definitely not a throwaway item from the cheapest sections at Target. It was sweet. Almost... innocent. Exactly what they needed.

After a few rounds, though, Lydia stopped laughing at another of Stiles' jokes rather abruptly. In turn, Stiles' eyebrows furrowed and everyone turned to her. Then her eyes glazed over, as if she was in a trance, and a faraway look took over her face. She stood just as quickly, her movements taking on an almost robotic quality, and she was stiff and rigid as she made her way to the door.

"Lyd?" Stiles called out. "Where are you going?"

He popped a mini marshmallow in his mouth as she pushed the door open, and that was when it seemed to hit Stiles. She wasn't with them anymore. Not really. She didn't even acknowledge that he'd spoken. And if there was anything everyone in this town knew, it was that Lydia and Stiles had a connection so peculiar it rivaled even his own with the pack human.

If she wasn't responding to him, something was up.

Stiles reached to stand in front of her, hands on her arms, stopping her movement forward, though her legs continued to walk in place. He let go with one to wave it her face, but she wasn't seeing anything.

Derek caught up to them quickly, covering the space between them all with a few long strides.

"Stiles, let her go."

Stiles looked first, hurt. Then, confused. And finally, mad. "Wh..."

Derek needed to express to Stiles that they very well might be able to get some of those answers they'd been seeking. Ones that had threatened to rid them of the last remaining shreds of their sanity recently. But he didn't have time. And he had no idea what would shake Lydia from this trance. He couldn't chance saying more than he'd already said.

"Let her go," Derek repeated.

"Let her go?"

Derek nodded. And Stiles did something that Derek would have found impossible when he first met him. He listened. He listened without any other prompting. He just dropped his hands and watched as Lydia turned and continued down the sidewalk. Then he turned back to Derek with questions swimming in his eyes.

"Derek, I...," he whispered.

But Derek just put a finger to his lips and motioned for Stiles to follow Lydia with him, putting a hand on his shoulder and giving it a squeeze. One of the many mysteries that had plagued their town was finally going to come to a fucking end.

Derek Hale could feel it.