Sam and Dean stood in the doorway of a supposed-to-be-vacant cabin, with Dean's gun drawn on 2 teenage boys and Sam flashing an FBI badge.

"FBI," he said, repeating his older brother. He watched as the kid who tried to attack Dean with the chair backing up to his pale friend.

"Dean, we're scaring them," Sam whispered.
"Good. That means they'll get the hell out of here quicker."
"They're just kids."
"So?" Sam gave him a quick bitchface and pushed the gun down so it was now aimed to the floor. He then stepped forward.
"I'm Agent Sam, and this is Agent Dean."

"Are we in trouble?" The taller of the two teenagers squeaked. Dean stepped forward to regain his position next to his little brother. He was about to say yes until Sam put his hand up motioning him to keep his mouth shut.
"What are your names?"
"I'm Blaine and this is Kurt," the shorter one said.
"Nice to meet you. And no, you're not in trouble."
"Then why is the FBI here?" Kurt asked.
"Because…" Dean stepped in and gave Sam an 'I got this' look. "We are searching for some missing-persons."
"In this cabin?"
"Well, the victims who stayed in this cabin eventually went missing."
The two boys gulped. "How many went missing?" the boy named Blaine asked.
"Thirteen over the past 20 years."
"When was the last disappearance?"
"Two years ago."
"I read that in the paper," Blaine informed, "Julie and Dan Adams? They said it was a bear attack. Not exactly missing-persons." Sam and Dean glanced at each other. "Yeah, it was a bear alright," Dean scoffed.
"You don't think so?" the higher-voiced boy asked.
"As a matter of fact I don't."
"But all evidence led-"
"There was no evidence," Dean cut it, "just a trashed living room with claw marks on the wall."
"Yeah, a bear," Blaine said with an uneasy laugh.
"How do you explain it getting in, huh? No reports of broken windows, and the door was undamaged. Only way in was the door, and most people lock theirs. Last time I checked bears can't open doors, let alone a locked one. What you're looking at is a Wend —"
Sam pulled Dean aside by his jacket collar.
"Calm down," he demanded, "we can't tell them these things. They're just teens."
"Fine," he spurted out after an intense stare down.

"When are you kids heading back?" Changing the subject.

"Kids? We're like, what, 5 years younger than you?" Kurt questioned, a bit offended.
"Yeah, aren't you a little young to be FBI," Blaine asked suspiciously.
"I asked you a question first," Dean snapped, though very non-threatening.
"I asked you first? What are you, seven?" Blaine joked.
"Don't make me come down there, hobbit." Dean was now invading Blaine's personal space.
"Down all three inches. You're not that much taller than me."

While Dean and Blaine were verbally attacking each other, Kurt made his way over to Sam. They both gave each other a look and simultaneously asked, "Are they always like this?" They both nodded. After a good laugh, Sam intervened. "Alright kiddies, time to break it up," he then redirected his attention back to the porcelain-skinned boy and asked, "when are you guys leaving the cabin?"
"Well, we were going to leave Sunday morning."
"But after tonight I think we should leave tomorrow morning instead," Blaine added, waiting for a nod of agreement from Kurt.
"What happened tonight?" Dean asked while nonchalantly raiding the fridge. Sam rolled his eyes.
"Well, the FBI for one. And the bear for two," Blaine answered, watching Dean pull out a loaf of bread. "Can I uh.. make you anything?"
"No, we're fine," Sam said. Dean protested with a frown. "Wait, hold on a sec. You mentioned a bear?" he asked with a mouthful of a sorry excuse for a sandwich,
"Yeah, before you two busted in there was something outside."
"Blaine reckoned it was a bear or something. I saw it run past the window, but I thought it was too fast to be a bear. My dad strung me along hunting once, didn't like it, but we didn't see any bears that were that quick. Maybe a deer, but it was making a lot of noise."

Sam threw Dean a look. Dean leaned in to Sam's ear and whispered, "It already knows someone's here. We need to get them out of here."
"Yeah I agree," he whispered back. "Blaine, Kurt, I think you two should head back tonight."
"Why tonight?"
"You guys are in great danger if you stay the night," Dean threatened.
"It IS just a bear, right?" Kurt pressed.
"No," Dean answered truthfully.
"Dean," the fellow hunter warned.
"Sam," the elder Winchester snapped back. "Just… just go pack your stuff and throw it in your truck or whatever."

The teenagers hesitated slightly, but finally compromised.

-x—

"All packed up," Kurt informed. Dean nodded and motioned them out the door.
"Should we tell them?" Sam asked once he and his brother were left alone in the cabin.
"Not if we don't have to. We'll just let the drive home thinking a bear or something was terrorizing their little vacation. The less they kno—"
"SAM!" Kurt scrambled through the door holding Blaine's hand.
"What is it Kurt?"
"Someone, or something, slashed our tires!"
All four boys ran out to their cars.
"Dean, it slashed the Impala's too!"
Dean rushed over to his baby like it was on fire.
"That son of a bitch!" He turned to the woods and yelled, "No one messes with my baby. NO ONE. I WILL HUNT YOU DOWN. YOU HEAR THAT? Dammit!" He kicked the tire out of frustration.
"It's okay, Dean," Blaine assured, "we'll have them fixed by morning—"
Dean laughed darkly. "No. It's got the upper hand; it's got the cover of night and cut off our only chances of escaping."
"What are you talking about?" the terrified countertenor croaked.
Sam looked at Dean who was too busy stroking his car and soothingly whispering to it. Sam sighed and told them all to go inside, because he'll explain everything.
"Everything?"
"Yes, Dean. About this case."