Truman High School was about half the size of Kat's school in California. There had been so many people in her grade, she'd hardly known a fraction of them. But Truman seemed to be one of those schools where everyone knew everyone. That wasn't ideal for undercover work. Every new person stuck out like a sore thumb. Or in their case, three.

And yet, small as the school was, Kat was willing to bet that her school had never had this many students in the nurse's office.

"What on earth is going on around here?" Nurse Hannigan demanded as an eighth student walked in sporting a bloody nose. "Go ahead and take a seat, Colby. Louise has the tissues."

"This is ridiculous." Kat sighed, straightening her skirt as she stood up from her desk. At least, it was temporarily her desk while Nurse Rally was out on maternity leave. "I'm going down there to talk to him."

"Oh, I wouldn't bother, dear. It's best to just wait it out. These people are notoriously difficult to deal with."

"Yeah, I'm gonna deal with him alright."

Her new coworker protested weakly, but Kat was already storming out of the room.

It was a feeble case at best. To be honest, Kat wasn't sure why they'd taken it. One bullied girl drowning a cheerleader in the bathroom and then saying she hadn't meant to didn't seem all that compelling to her. But Sam had been all for checking it out anyway, just to be sure. Dean had played right along, and since they were effectively her bodyguards now, Kat had no other choice.

That was one reason she was already in a bad fucking mood. No one wanted to relive high school less than she did.

Her high heels clicked powerfully as she marched down the hallways. The sound made a couple of freshmen loitering by the water fountain scatter. But she didn't plan on stopping to reprimand students. She did not stop until she'd reached the gymnasium.

A wave of bitter nostalgia hit her as soon as she was through the doors. All gyms looked the same she supposed, but there was something about the squeak of sneakers on polished wood floors that always made her gut clench. She tried to stay focused, scanning the room for a teacher, and stopped dead as soon as she'd found him.

Kat hadn't gotten the pleasure of seeing Dean before they'd left for work. Her Prius was far less conspicuous than Dean's car, so she'd been the one up six in the morning to drive Sam the Janitor to school. She'd gotten herself ready, swung by a coffee house for breakfast, and been back on campus before school started at 9:05. Dean had slept in, because Truman High School did not run gym class until second period.

She hadn't expected him to get so into it. On the other hand, part of her wasn't surprised to find Dean in his element bossing around a bunch of teenagers. Back to the wall, he was refereeing a brutal game of dodgeball. As much as you could referee dodgeball anyway. It didn't look like anyone was keeping score. Dean just kept his eyes on the hoard of students and blew his whistle whenever he saw someone get hit. Then they'd take a lap, or head straight to the nurse's office.

No, it wasn't his enthusiasm that caught her off guard. It was his dumbass uniform. He had a school printed polo, striped tube socks, and a sweatband—like he'd just walked out of some corny eighties movie. But the shorts took the cake. Even in her worst nightmares Kat wouldn't have imagined Dean in shorts that tight.

He didn't seem to notice her revulsion. The moment he saw her walk through the doors his face lit up. He abandoned his post, and Kat had about five seconds to brace herself before it started.

"Come on," Dean groaned when he was within earshot. "No lil' nurse costume? If I can't sing 'Hot for Teacher' you could at least make it worth my while."

Her hands curled into fists at her sides. But there wasn't much she could do in a room full of school children. She gritted her teeth, mentally repeating the mantra her mother had left her with.

"God grant me the serenity to accept what I cannot change, the courage to change the things I can, and the wisdom to know the difference."

She gave Dean a tight smile.

"I think I'll leave the outfits to you," she said, giving him another once over. "Nice plum huggers."

"They're sick, right?" Dean beamed with pride, looking down at his shiny new sneakers. "And they just give 'em away to everyone in the athletics department."

Kat was too overwhelmed by pity to correct him.

"And," he added holding up his whistle, "watch this!"

He stuck it between his teeth, letting out a long blast that made even Kat jump. Everyone in the gym froze, the only sound the abandoned balls dribbling and rolling across the floor.

"Half-time!" Dean bellowed to his class. "Everyone take a lap. Finish first and the stragglers are fair game!"

The effect was immediate. Jocks and nerds alike tripped over themselves to make it to the front of the herd, half fueled by bloodlust, half by fear. Dean couldn't have looked prouder. Kat watched him disparagingly.

"People like you are the reason no one trusts authority figures."

Dean huffed, grumpily dropping his whistle once more.

"Whatever. You come all the way down here just to rain on my parade, or do you actually have something to say?"

"I do, as a matter of fact. I have a ton of kids in the nurse's office with bloody noses. Like, a scary amount of kids."

"You think it's related to the case?"

"No," she deadpanned. "No, I don't."

To punctuate this, one of the seniors helpfully pegged his friend in the ankle. The other boy lost his footing, falling forward and slamming face-first into the ground. Kat and Dean winced in unison, watching as the boy limped out of the gym with his hands over his face.

"Hey, good hustle, Johnson," Dean commended. "Get some ice. Keep it up."

"Dean, I'm serious," Kat sighed. "You can't..."

"Hey, that's Substitute Coach Roth to you," he corrected. "I'm not letting you compromise the integrity of this case."

Kat saw red.

"Alright Substitute Coach Roth," she growled. She took a step forward, jabbing a nail into his chest. "As a certified educator of the state of Indiana, I'm sure that you're extremely familiar with Fairfax County's curriculum restrictions. Yes?"

"Uh...yes," Dean said nervously. "Of course, Nurse Fletcher."

"Good. Then I'm sure you're aware that this district has prohibited dodgeball in physical education classes."

"If they don't want the kids to play dodgeball," Dean said, picking one of the stray balls from the floor, "then why do they stock dodgeballs?"

"They're for kickball, dumbass. So scrap your syllabus and start over. If I get one more kid with a bloody nose in my office, we're sending someone to shadow your classes."

Dean's pout slowly spread into a mischievous grin.

"Is that so?"

Later, she'd realized she was being idiotic. There was no excuse for her to be surprised when the ninth student wandered in for tissues, head tilted back so his blood wouldn't drip on the floor. Kat listened to him stumble into a seat, and let her face fall into her hands.

"Goodness gracious," Nurse Hannigan declared, breaking three more tissue boxes out from the supply closet. "Chester, what happened to you?"

"Dahs-bahl," Chester answered nasally. "Coach Roth waz giffing a dehmonstration and he gaht me in tha nose."

"For heaven's sake! What does he think he's doing down there? I thought you said you went down there to warn him, Fletcher!"

"Yeah, I did," Kat groaned. She did not have the strength to lift her head. "I think that's actually part of the problem."

"Oh...? Oh!" The woman laughed, which was not particularly comforting. She patted the edge of Kat's desk and lowered her voice consolingly. "Well, don't look too glum dear. At least Coach Roth's a looker."

"Margot!"

"Please, I'm married, not dead. Go on down there and see if you can knock some sense into him. At least handle some of the minor injuries, if you can. The cots are about to overflow down here."

So, armed with a first aid kit of cotton balls and band aids, Kat trudged back down to the gymnasium. There was a new batch of students, still playing dodgeball, still running laps. Whatever restrictions the school district might've had it place, it was going to take a higher power than the Truman High PTA to scare Dean Winchester into submission.

Dean was waiting for her smugly, his feet kicked up on a folding chair.

"I cannot believe you assaulted a minor to get me down here," Kat complained, swatting him with her go bag.

"Hey, that one deserved it," he chuckled. "He was a bully—total ball hog."

"Yeah, well it takes one to know one."

"Excuse me, I'll have you know I never even attended gym in high school."

"Right," said Kat with an eye roll. "The criminal."

"Oh, let me guess, Molly Ringwald—the princess?" When Kat didn't answer him, his head snapped up. Again, his leer was spreading. "Oh yeah, I forgot. You really were Little Miss Pep Rally, weren't you?"

"Dean, it's not funny."

"It's a little bit funny," he said happily. "You know, that reminds me. They actually asked me to oversee cheerleading practice after school. Can you believe that?"

"I wouldn't worry. I'm planning on talking to the principal and making it very clear that you're not allowed to be within a hundred yards of a school."

"Very funny. Or instead you could—hey!" Dean blasted his whistle again, waving a warning hand at some of the boys fooling around in the corner. "Don't think I didn't see that, Peters! I put you on blue team for a reason! You wanna mess with someone, you mess with each other. No ganging up!"

"You actually put them on teams?" Kat asked, surveying the mass of children. Upon closer inspection, it did seem a little more organized than the previous period.

"Tried to, anyway. Figured it'd make it fairer, but the little bastards keep switching. Anyway, I was thinking maybe you could come with me."

Kat blinked down at him.

"Excuse me?"

"To cheer practice," he elaborated. "I mean they just need an advisor there to make sure the girls aren't painting each other's nails or whatever, but I don't know shit about backflips and round-offs. So what'dya say? Wanna relive the glory days?"

Dean looked up at her, and he almost managed to look innocent. Then Kat yanked the chair out from under his feet, and he lurched forward with an unmanly squawk. It took all of her self-control not to throttle him, not to scream and punch until she'd gotten rid of frantic, panicked feeling that was clawing the inside of her ribs.

"No dodgeball," she said tersely. "Enough."

She folded the chair against her side and marched away before he could say anything else.

The rest of the period could have been worse. Dean regrouped the students, and actually started reffing the game instead of sitting back to watch the chaos. Crazily enough, under constant supervision there were less staggering injuries. Kat set up a few students on the bleachers with ice packs and bandages, but there were no more bloody noses. Even the meanest jocks weren't brave enough to peg someone in the face with two teachers watching.

Five minutes to the end of the period, Dean sent the kids to hit the showers. Kat packed up her things as fast as she could. If she finished before he did, she might get out without another confrontation. But she should have known better. Dean made no move to pack up any of the stray dodgeballs. He strolled straight for her spot on the bleachers.

"You know," he said, tossing one of the balls between his hands, "I still think it's dumb that the only one of us trained to work in a gym didn't take the gym teacher slot."

"Yeah, well the only other position was nurse, and you weren't going to do anyone any favors down there."

"What is that supposed to mean? All you've gotta do is slap a few band aids on 'em, send 'em back to class."

Kat snorted, shaking her head.

"I don't think there are words to describe how happy I am that you don't actually work in public education."

"I'm just saying," he said with a smile. "I kinda wanted a chance to see you in action."

"Dean, you've seen me in action. I've kicked your ass in action."

"I meant teaching," he corrected sourly. "Sam says you're pretty good."

"Well, I'm flattered. But I'm trained to teach women, not sixteen-year-old gremlins."

She closed her first aid kit with finality, brushed herself off, and headed for the door. She almost made it too. And then with a resounding thwack, one of the dodgeballs slammed into her back.

Kat whirled around, but Dean was staring innocently at the ceiling, his hands clasped behind his back.

"Okay, I know you did not just fucking do that."

"Do what?"

"What are you, seven? Knock it off, Dean."

"Come on, Kat," he laughed, picking another ball from the floor. "Live a little! How about a little one on one?"

"You've gotta be kidding me." She glared at him, but his happy little smile never faltered. "Dean, you're wearing sneakers. I'm in a dress and three inch heels."

"Talking dirty ain't gonna get you out of this," he said with a wink. "Come on. Don't pretend like throwing something at me isn't gonna make you feel better."

He bounced the ball to her, and Kat caught it with surprise. Dean stepped back, his arms held out wide, making himself as big of a target as he could. He was being one hundred percent serious.

Kat considered him for a moment, then dropped the ball back to the ground.

"Geez," Dean groaned. "You're such a party pooper."

She waited until he'd turned around to pick up the rest of the balls. Then, with surprising accuracy, she kicked the ball and sent it rocketing into the back of his thigh. Dean yelped, grabbing his ass, and Kat couldn't help but burst out laughing.

"I told you," she managed through her giggles. "They're for kickball."

"That was cheap," he grumbled. "If you wanna play like that…"

He slung another ball at her, and Kat only just managed to side step it without tripping over her heels.

"Hey! I am not playing this game with you. Maybe you have the period off, but some of us have work to do. So I'm going to go back to my office, and next time you have a class, you are not going to play dodgeball. End of story."

She made a second attempt to leave, only for Dean's voice to stop her dead in her tracks.

"Oh yeah? Make me."

"Excuse me?" said Kat, turning back to glare at him.

"One on one." He rotated the ball in his hand, goading her. "We'll make a little competition out of it. First one to land a hit wins."

"Of course," Kat sighed. "Cause you're always looking for something. What exactly do you expect to get from…?"

"Nurse outfit."

She glowered at him.

"You know, for someone so worried about the integrity of the mission, it's great that you don't think it would be weird for the school nurse to wear slutty scrubs."

"Hey, I did not say slutty. You filled in the blanks."

"Forget it, Dean."

This time the ball collided with her shins, too quick for her to even turn around. Kat's jaw clenched. She was not going to let him trick her into this. She was not going to let him piss her off until she gave in.

"Alright, we'll compromise," he offered. "No nurse costume. But if I hit you, you have to go undercover next case. You go all out—costume, fake name, the works. And if you hit me, I'll end dodgeball."

"No way," Kat laughed. "Are you insane? You don't get to trade child abuse for public humiliation. That is not an even deal at all."

"Okay. Then tell me what you want."

Dean bounced the ball to her again. Kat spun it between her hands, testing the weight. The only thing she wanted from Dean Winchester was silence, but she knew that was a tall order. Even if she could come up with something good, she knew there was a good chance he wouldn't give it to her. He'd find some loophole and weasel out—that was just what Winchesters did. Yes, the smart thing to do would be to drop the ball and walk away now. He'd rag on her for the rest of the week, but he'd eventually find something else to obsess over. Better that than risk losing.

Kat liked to think that she was smart. But she was also proud.

"Hey, it's okay, Kat," Dean said with a placating grin. "No shame in walking away from a fight you can't win."

"And what is that supposed to mean?" she challenged.

"Nothing, nothing. Like you said—you're in heels, I'm in sneakers. And maybe you're trained in self-defense, but on offense...I think we both know who'd come out on top."

It was playing right into his hands. But Kat maintained eye contact as she kicked off her heels and chose a ball from the gymnasium floor.

"I want to pick all the music in your car for a month."

"What? You don't even ride in the Impala."

"I know."

Dean considered her, chewing on the inside of his cheek. He tipped his head to the side in ascent.

"Alright. So, to recap…"

"If you hit me first, I will go undercover on the next case. Assuming, of course, that the case calls for it."

"Of course. With costume, or no deal."

"Fine. And if I peg you, you end dodgeball and I'm in control of your music for a month. And I will make sure Sam's enforcing that."

"Wait…" Dean's face twitched and he held up a hand. "What did you say?"

"Please. You think I'm dumb enough to trust you to listen to me? I'll make sure Sam knows to…"

"No, before that. The—The first part."

"I said, if I peg you, no more dodgeball, and I get to pick your music."

"I can't—sorry. Gyms, you know—the echo—one more time?"

"Jesus, I said if I peg you…" She watched his face twitch again, his body shaking with barely contained laughter, and realized her mistake too late. "Oh my God, you're disgusting."

"Ha! Hit me with it, Tinkerbell."

Kat would've walked out of the gym just for that, but Dean chucked another ball at her before she could make a getaway. She yelped and dodged it, spun and barely shirked the second. There was nothing left but to fight back.

It was hardly a minute before Kat realized she had broken her own personal rule—never underestimate your opponent. The Dean she'd been prepared to fight was the one she had taken down on the highway months ago, the Dean who had fallen on his ass trying to pick the lock on her motel room. But that was Dean caught off guard. This was Dean on his game. And while he might have been a narcissistic asshole, it didn't change the fact that he was an experienced fighter, and that he was damn fast. Kat was probably faster—but that was when she wasn't dressed in a pencil skirt.

The ball collided with her leg with a resounding thwack, so forceful that she nearly toppled over. She cursed loudly, waving her arms to regain her balance. But Dean didn't offer her any kind of consolation or support. He was already jumping in the air, his joyful whoops echoing around the gym as he fist-pumped his victory.

"Ha ha! Yes! Oh, God, your face! Holy shit, that was satisfying."

"Ow! What the fuck, Dean?"

"Oh, man. One point, Coach Roth. Zero to the hack-job school nurse."

"Asshole," Kat grumbled. She rubbed sorely at her thigh. "You didn't have to launch it at me."

"What was that? Sorry, I uh—I couldn't hear you over how awesome I am."

"Try not to gloat too much," she said, rolling her eyes and slipping her shoes back on. "It wasn't exactly a fair game."

"Hey, you agreed to play." He smiled at her with expression that oozed smugness from every pore. "Don't worry, sweetheart. I might not even make you wear fishnets."

Kat wasn't sure if she turned white or red faster. She chucked the closest ball at Dean, seething as he dodged and cackled.

"No fucking way, Winchester. I told you, undercover, if the case calls for it. That means…"

"Jeez, I know what it means, Kat. Will you relax? I'm just yanking your chain."

She huffed, aiming another half-hearted kick at the dodgeballs on the floor. Before Dean could retaliate, the phone on the wall of the gymnasium began to ring. He moved to answer it, and pinned the receiver between his ear and shoulder.

"Truman Gymnasium, Home of the Bombers, this is Substitute Coach Roth."

Kat flipped him off, prompting Dean to stick his tongue out at her. However, his face quickly dropped. Whatever the phone call was about, it left him with a decidedly stony expression.

"Yes, ma'am. Absolutely." He hung up, and turned back to Kat gravely. "Home ec. We gotta go, now."

"What happened?"

"Jock just lost his hand in a food processor."

The urgency with which he bolted for the door told her everything she needed to know. She'd have to apologize to Sam for doubting him. Mentally, anyway.

The closer they got to the home ec wing, the more crowded the hallways became. People were whispering and shouting in confusion, trying to figure out what was going on. There was an air of concern, but mostly of excitement. Students and teachers alike were hovering like flies over a carcass.

"Hey, everyone back to their classrooms!" Dean bellowed. "Nothing to see here! Back to your classrooms and wait for instructions!"

"Guys?"

Sam's head was sticking out of a classroom a few doors down. He looked stricken, and waved frantically for their assistance.

"Go," Dean instructed, nodding to her. "I'll take crowd control. You go…nurse, or whatever."

Kat shoved her way through the crowd, following Sam into the hastily abandoned classroom. It was a wreck, to say the least. Deserted workstations were covered in dripping eggs and bits of celery, one or two splattered with fresh blood. Kat followed the trail from the door to a table in the middle of the room. The food processor was washed with scarlet. Kat was thankful someone had turned it off at least—she could still see bits of flesh and bone inside.

"Hey, gimme a hand?"

Sam waved to her from the floor, where he was crouching over a body. It was a student, apparently unconscious and absolutely drenched in blood. Kat braced herself, but this one seemed to have all his fingers intact.

"This the kid that did it?" she asked, kneeling down on his other side.

"Yeah, just like last time," Sam confirmed. "I was just outside, came in as everyone was running out. Kid looked like he was in a trance, just collapsed and asked me what happened. Then he passed out."

"Maybe he wasn't a fan of the blood."

"Makes two of us. But look at this."

Sam tilted the boy's head, turning his ear into the light. A thick, black substance was oozing out, pooling on the white tile below.

"God, please tell me you know what that shit is," Kat pleaded, wrinkling her nose.

"Yeah. It's ectoplasm."

"Excuse me?" Kat gaped at him, both horrified and exasperated. "What, are we the fucking Ghostbusters now?"

"It's rare, but really powerful ghosts have been known to produce it. And there's enough lore on spirits taking on a host when want to interact with the physical world."

"So what? It's strong enough to produce ectoplasm but not strong enough to kill its own victims?"

"I don't know. Maybe it's trying to keep a low profile?"

"Right," Kat scoffed, glancing around at the bloodstained tables. "This is real low key."

"Either way, this explains the girl's story. No sulfur, no smoke, cause there's no demon."

"So what do we do now?"

"Regroup, I guess. Start working it like a normal ghost case. Check death records, school history…"

His sentence was cut off by yelling in the hallway. Two security guards marched into the room, zeroing in on Kat and Sam almost instantly.

"Got him," one of them said into his radio. "We'll bring him down now."

"Miss, if you'll step back," said the other guard.

He swept her out of the way before she could think to argue. The first guard had pushed Sam aside and was already rolling the teen onto his stomach, yanking his arms behind his back.

"Hey!" Kat shouted, beating at the guard that was holding her back. "What the hell do you think you're doing? That's a student!"

"Yes ma'am," the first guard agreed, still shoving the boy's body. "A student that just chopped off the hand of another student. He's a danger to himself and others."

"And he's still a student!"

Both men ignored her. Frustrated, she sharply brought her elbow down over the arm that was holding her back, making the man yelp in pain. She rushed forward, batting the others out of her way and checking the boy again.

"Miss," the first guard complained, "if you're not going to cooperate…"

"You mean let you manhandle teenagers?" she snapped. "Look at him. He's not resisting. He's unconscious, because he fainted and he might have a concussion. He might have been drugged, he might be dying, he might be faking, but until we know for sure, it's my job to make sure these kids stay healthy and safe. Get the picture?"

He considered her grumpily. His eyes flicked over her shoulder to his coworker, looking for some kind of back up. But judging by the sounds he was making, the other guard was still cradling his arm.

"Fine," the guard huffed, dropping his gaze. "But don't come crying to me when you lose your ring finger."

Kat restrained herself from swinging again.

"You can gently carry him to nurse's office. I'm sure the authorities will have their own questions for him, but I'd like to assess his condition before he goes anywhere."

The man rolled his eyes at her, but was careful as he picked the boy up from the floor. He nudged his partner out of the room first, and Kat hesitated a moment before following them. She turned back to Sam.

"Okay, I'm just gonna make sure they don't kill this kid before he gets to an ambulance. I'll try and keep it short so I can meet you guys back at the motel and…"

"No, you should probably stay down there. Dean and I got this under control."

"Yeah, but I…"

"…am undercover," Sam finished firmly. "Remember?"

Kat groaned, squeezing her head in her hands.

"Jesus Christ. Have I mentioned how much I hate the way you guys work cases?"

"Uh, yeah," he chuckled. "Only about a hundred times."

"Well make it a hundred and one. There is no reason all three of us should be undercover right now."

"I know. But you were the only one qualified for the nurse vacancy, and that gets us easier access to the school records. I can go just about anywhere as a janitor, and Dean…"

"Just wanted to play dress up."

Sam withered, but tilted his head in agreement.

"At least he's out of your way?" he suggested hopefully.

"Right. And he gets to play dodgeball while the rest of us work. Whatever." Kat shook her head as she headed out of the classroom, calling back to Sam over her shoulder. "Just do me a favor and get a picture of him in those shorts? I wanna send that shit to Jo."

A/N: Boy is it good to be back! I'm really excited to share the second phase of this story with all of you. Hopefully there are still enough people interested in sticking around. I promise, the second half of season 4 has some real gems.

As usually, I just want to recap some house keeping. Today's return chapter is a special posting for Dean's birthday! Happy Birthday Dean Winchester! This story will continue to update on Tuesdays, which means you can expect Chapter 41 in just a few short days. If you're interested in seeing the trailer I made, and what Act II has in store, please check out the story's tumblr blog at gospelofthechosen.

Thank you all so much for reading, and sticking with Kat all this time. Can't wait to hear from all of you again!

-Brittney