It's a Werewolf Thing

The lacrosse match was fierce and ended with Beacon Hills smashing their opponent, thanks mainly to the four werewolves that were on the pitch. To everyone's surprise, Coach Finstock had let Stiles play for the last few minutes and that surprise had quickly turned to excitement, when Stiles had managed to get the ball in the back of the net.

Once the match ended, Kacey, Derek, Allison, and Erica waited for the others to get changed, ready for movie night at Derek's. It had become a tradition, something they did after every lacrosse match and it was good for pack bonding.

As they waited, Kacey's phone vibrated in her pocket and she pulled it out to find a new message. Not recognizing the number, she opened it and froze as she read it. 'Being human can be a huge disadvantage in this dangerous world, especially in a world roamed by wolves... what a shame that Mr. Stilinski will have to learn this the hard way.'

Kacey was running before anyone could ask what was wrong, heading to the changing room and nearly crashing into Scott as she threw the door open. Her eyes scanned the room, but Stiles wasn't there and panic began to rise through her.

"Where's Stiles?" Kacey asked.

"He left his phone down by the field, so he went to get it..." Scott replied.

Ignoring the calls of her name, Kacey rushed off towards the field with the pack on her heels and felt her heart drop as she spotted Stiles lying on the ground. Falling to her knees at his side, she didn't have to look properly to know he had been beaten up and it made her blood boil.

"Stiles?" Kacey whispered as he opened his eyes with a groan.

"Ow... Jesus, did I get hit by a bus?" Stiles mumbled, taking the hand that Kacey offered and grimacing as she carefully helped him sit up.

"Not quite... I'm pretty sure it was my dad," Kacey told him, feeling guilt wash over her and backing off so that the pack could get to him.

While they were concentrating on Stiles, Kacey headed back towards the school and found her dad leaning against Stiles' jeep smirking.

"The supernatural world is a dangerous place for any human, but if you run with the dogs you will end up getting hurt..."

"You're seriously twisted in the head... what hell did Stiles do to deserve what you did to him?" Kacey shouted, feeling the familiar electrical charge spark within her, "You can't just go around attacking people."

"Why not?"

"Being a hunter doesn't give you the right to go around hurting whoever the hell you like," Kacey added.

"It gives me the power to make my point very clear, that is how it's going to go if you don't join me," her dad growled, pushing off the jeep and stalking towards her.

"You're nothing but an animal. I don't need until the full moon to know where my place is and if you ever lay so much as a finger on any of my family again, I won't hesitate to end your life like you ended my mothers," Kacey warned.

"Don't threaten me, little girl, because it won't take much for you to disappear," her dad seethed as he moved into her personal space, "Your dogs won't always be around to protect you."

Swallowing nervously, Kacey quickly relaxed as a low guttural growl sounded from behind her and watched as her dad backed away.

"Are you okay?" Derek inquired, walking over and standing at her side.

"Yeah, I think we're done here," Kacey replied as the rest of the pack, including Stiles, gathered around them.

"We're not done here, Kacey-Jae," her dad snapped, stepping forward and pausing as the pack growled.

"I suggest you back off," Derek warned, snaking his arm around Kacey's waist and pulling her closer to him.

"Stay out of this mutt."

"There's nothing left to say, I made my decision and you won't change my mind. I will always choose to stand with the pack..." Kacey announced, feeling Derek relax a little at her side.

"That makes you my enemy and you will be treated as such, from now on I have no daughter... you're dead to me."

"You lost me way before today," Kacey stated, watching as her dad got in his truck and drove away.

Looking up at Derek, Kacey followed her over to the Camaro and climbed into the passenger seat. Arriving back at the Hale house, she took Stiles straight into the kitchen and ignored his complaints as she cleaned up his face.

"What are we watching?" Jackson asked.

"Not the Notebook," Kacey and Stiles shouted in unison.

"Why not?" Lydia whined.

"We've watched it five times already and it doesn't get any better, can't we watch Transformers or something," Kacey added.

"Fine," Lydia agreed reluctantly.

Kacey finished cleaning Stiles up, before they both sat on the sofa and waited for the film to start. It wasn't long before the pizza arrived and they paused the movie to eat, but Kacey wasn't hungry so she remained curled into Derek's side as everyone else tucked in.

"Kace, you not eating?" Stiles asked through a mouthful of pizza.

"I'm not all that hungry to be honest," Kacey mumbled, covering her mouth as she yawned, "I feel like I could sleep for a hundred years though."

"You've been tired a lot lately," Derek commented sounding concerned.

"I'll be alright once everything is dealt with and I can get my sleep pattern under control," Kacey reassured everyone with a small smile as Jackson put the film back on.

Almost everyone was asleep by the time the film had finished, except for Kacey and Stiles who were sitting out on the porch. The first wave of nausea hit abruptly, causing Kacey to double over and grimace as pain shot through her stomach.

"Kace?" Stiles said with panic clear in his voice.

"Derek," Kacey groaned as the door opened and Derek appeared at her side.

"What's going on?" Derek inquired, crouching down and rubbing soothing circles on her back.

"I don't know, but I really don't feel good..."

"Perhaps Deaton will have some answers," Stiles suggested, watching as Kacey doubled over again and moving forward to help Derek get her to her feet.

Helping Kacey to the car, Stiles jumped in the back with his phone to his ear and held on tight as Derek pulled away from the house. Deaton was already waiting for them when they arrived, clearing off an operating table and motioning for Derek to lay Kacey on it which he did.

"How long has she been like this?"

"About half an hour," Derek answered quickly, watching closely as Deaton examined Kacey, "What's going on?"

"The energy that Kacey will use when she has her full powers is somehow already growing rapidly," Deaton explained with a frown, "I'm not sure how, but I do know that if it gets too strong it will cause Kacey's heart to give out and she will die."

"We can stop it though, right?" Stiles inquired.

Deaton was silent for a few minutes, watching Kacey before nodding and turning to Derek.

"You have to bite her," Deaton announced hesitantly, "It's the only way to stabilize the energy."

"Hang on, it's not a full moon tonight," Derek argued, "You said that it had to be done on a full moon."

"She won't see another full moon if you don't bite her, do you understand that?" Deaton replied, "You have two choices, you either bite her or she dies?"

"Are you sure it's the only way?" Stiles asked earning a nod from Deaton.

"Derek... do it," Kacey told him with tears running down her face.

Walking over, Derek pushed a stray hair out of her face and kissed her head. Glancing over at Stiles who had tears in his eyes, he took a deep breath and returned his attention to Kacey.

"Okay," Derek agreed, knowing that he didn't have any other option, "This is going to hurt, baby."

"Just do it," Kacey mumbled, holding out her hand to Stiles who took it and gave it a squeeze to show that he was there.

"I love you," Derek whispered in her ear, before shifting and sinking his teeth into her wrist.

Screaming as his teeth cut through her skin like sharp knives, she gripped hold of Stiles' hand until her body fell limp and her heart slowed down. Listening closely, Derek heard Kacey's heart beat a few more times and felt a wave of grief hit him as the room fell silent.