A/N: This one was another anonymous request on Tumblr, hoping for Cas being protective of Kevin and Charlie, who love him for it. Enjoy! The boys aren't in this one, so it's sort of a TFW 1.5, haha.

Setting: AU, no specific timeline, but Charlie and Kevin both lived and ended up going on adventures together.

Summary: Kevin and Charlie were both good at getting in trouble. Fortunately, there's someone they can count on to come through for them in a pinch.

Besties

"Castiel? Um… Cas?"

The angel cocked his head to the side with a light frown, listening to the anxious prayer. It wasn't a voice he recognized, but she clearly knew him.

"I- I don't know how this works, but if you can hear me, we need your help. And, you know, being best buds with Sam and Dean, I know you're one of the good guys… And in the books you're always jumping in to save people, so, um, we could… you know, use some saving? Oh! Oh, help, please help…"

The voice squeaked in alarm. Grasping that fear like a tether, Castiel immediately spread his wings and followed where it led. He landed in an alley, drenched within seconds as rain poured from the sky in a blinding deluge. Puddles on the cracked pavement reflected the forms of four demons. They stood in a semi-circle, enclosing two humans with their backs pressed against the wall.

One of them, Castiel knew; Kevin Tran was clutching an old book, shielding it nervously as a red-headed woman shielded him in turn with a short knife. It wouldn't do the slightest bit of good against a demon but she wielded it gamely with an expression of terror masked in fierceness.

"Hand it over, there's a good lad," one of t, he demons cooed. "Crowley's gonna want to see you two. Been a while since his kingliness had any fun."

The nearest demon took a step forward; the woman yelped and slashed out with the knife, earning nothing more than a round of raucous laughter from the attackers.

"Fiesty one, ain't she?" another demon cackled. He reached out and grabbed the woman by the wrist, hauling her towards him while she shrieked and tried to thrash away.

"Hey!" Castiel strode forward, invisible wings folding behind him. His glower darkened, a rival to the torrential sky. Lightning dropped from his sleeve in the form of a sharpened blade.

The demons straightened, trading uncertain looks, even as Kevin sighed with relief. The red-headed woman raised her eyebrows hopefully.

"…Cas?"

He lifted his chin in affirmation but didn't turn his gaze from the demons. "Leave," he growled at the hell-spawn. "Or die. I don't care which."

"After we get what's ours-" one started.

She never managed to finish, given the silver blade piercing her throat. Castiel ripped the blade back out so that blood spattered the ground. His expression remained cool.

"Anyone else?"

The remaining three retreated a pace, releasing the red-haired woman. The one who'd grabbed her hesitated, then tried,

"But… Crowley said not to come back without-"

Castiel's blade flashed again, orange spurting from the second demon's gut. The long-dead human host collapsed, empty. He turned to the last two demons, who immediately backed away. Castiel advanced far enough to plant himself squarely in front of Kevin and the red-haired woman.

"And you can tell Crowley," he snapped, "not to send any more demons after these two unless he's hoping to lose more followers. Now get out."

They fled, clouds of smoke chased by the angel's withering glare. Once they were nothing but a bad smell in the wind, Castiel turned to the two humans.

"That was wicked cool!" the woman babbled. "Seriously, the books never did you justice. You're like, Elrond and Obi-Wan mixed into one!"

Castiel raised his eyebrows, no idea what she was talking about but amused at her enthusiasm. He blinked as she punched him in the shoulder, beaming.

"You saved our asses! I'm Charlie."

"I thought you might be." The Winchesters' description of their friend did no justice, either. But he gathered she was not someone who could adequately be explained. "Are you two alright?"

"I think so," Kevin replied shakily, still clutching the book in a white-knuckled grip. "Cas… thank you. How did you know?"

"Charlie called me."

"And you really came," Charlie marveled as she reached out to grip his arm. "Out of nowhere. It was so badass. You're my new hero."

"Yes, well…" Castiel stowed his blade and rubbed the back of his head. He wasn't sure how to respond to the earnest enthusiasm. "They shouldn't trouble you again. Do you have somewhere safe to go?"

"Actually, we're trying to find Sam and Dean," Kevin said. "We didn't dare stop long enough to call. This book," he went on, gesturing to the saturated tome he was guarding. "They need to see what's in it."

Castiel nodded. "Hold tight, then. I'll get you to them."

Kevin nearly crumpled with relief, taking the angel's other arm. "Seriously, man, thank you. I thought they had us for sure. Just- I don't even know how to thank you."

Looking from one to the other, Castiel found himself taken aback by the depth of gratitude in their expressions. He cleared his throat. "Um… you're welcome. It's nothing. You're friends of the Winchesters. That makes us allies."

"Allies? We're besties now," Charlie informed him with a brilliant smile that Castiel couldn't help but find contagious and endearing, not dimmed in the slightest by the pelting rain or the danger they'd narrowly escaped.

His lips twitched and he harrumphed. As close of a family as he and the Winchesters were, he was already sure that he would thoroughly enjoy being "besties" with these two as well.