Written for the LJ 2011 Wishlist.

Requested By: AwesomeGeek

Fandoms: Castle/Supernatural

Characters: Castle, Beckett, Chuck, Dean, Sam

Summary: Castle faces off with Chuck after the latest Supernatural book upsets Alexis.

Setting: After S7 episode The Girl Next Door

Warning: Spoilers for season 7 (mainly the episode "The Girl Next Door")

Destructive Criticism

"So you think this guy is actually the key to the whole murder? That he knew his best friend was sleeping with his wife the entire time?" Castle asked, rushing down the sidewalk to keep up with Kate's determined strides.

"I think that it's impossible to know someone that well and not know," Kate said as she dodged something nasty on the sidewalk. "They'd been married for eight years, and he'd been friends with Lance since they were kids. There's no way he didn't at least suspect something was going on. Maybe he didn't know exactly what, but I'm pretty sure he would've worked at finding out."

"He finds out what's going on between his wife and his best friend and goes into a rage, killing them both," Castle nodded as he hypothesized.

"He certainly had motive. But even if he didn't, he still might've dug up something we missed while he was looking for answers."

"What about-"

The ringing of Castle's phone interrupted him. He raised a brow as he looked down at the screen and held up a finger to Kate. He stepped over toward the buildings to their left to get further away from the foot traffic on Fifth Avenue and answered.

"Alexis? What-" He stopped, his curious expression morphing into concern. "Sweetie, calm down, I don't-" Castle said, his face grave and voice in that serious parental mode that proved every once and a while that her really was an adult.

Kate moved closer to him, worry shooting through her. Over the sound of the city around them, she was able to hear the distraught tone of Castle's daughter's voice and even catch a few words.

"Dean … lied … stabbed … dead … kid…" Then a taxi driver laid on his horn and the rest was lost to her.

"Castle?" Beckett asked, alarmed. Stabbed and dead were two words that always put her on red alert

But Castle just waved his hand at her in a 'stand-down' motion. "It's just a book, Alexis."

"A book?" She mouthed, but Castle ignored her

"I know you really get into the characters, honey. I do, too. But you can't let them get you so worked up. They're not real."

After a few more minutes of placating, he got off the phone, his face still grim. Before Kate could ask him what the hell was going on, he'd already called someone else.

"Gina… No, the new manuscript isn't quite ready yet. No- Will you shut up for a second? I'll get it done, okay. Don't I always? … It's fine. Listen, I need to get in touch with Chuck Shurley. Can you get me his number, or at least his publisher's number?" After a beat, a dark smile flashed across his face. "Perfect. Thanks."

He hung up and stuffed his phone in his pocket, then moved toward the street.

"You'll have to go interview the husband on your own, I have something to take care of," he said, flagging a taxi. Then he muttered, "Probably would be better if a cop wasn't there…"

If she hadn't already decided to go along, that last sentence would've clenched it for her. The writer got himself in enough trouble without meaning to, she didn't really want to see what he could accomplish when his mind was actually set on mayhem.

"Wanna tell me what's going on, Castle?" She asked/demanded as she slid into the taxi with him.

But all Castle would say was that he needed to pay someone a visit. Kate wanted to ask more questions - where they were going, who they were going to see, if Alexis was alright - but the serious expression on Castle's face as he watched the scenery go by without really seeing it didn't invite an interrogation. So she decided to just go along with it, let him do what he needed to do, and make sure he didn't get into any trouble along the way.

The taxi stopped a few minutes later outside the Javits Convention Center. Kate followed him in, looking around in confusion and wonder just what the hell was going on. Inside, there were guys (and some girls) standing around dressed in variations of the same outfits. A lot were wearing tan trench coats with rumpled suits, some were dressed as monsters, including the ugliest scarecrow Kate had ever seen. But what really caught her eye were the ones in the plaid button down shirts with jeans, work boots and Carhartt or leather jackets. Not because the outfits were particularly eye catching or because there were so many of them, but because they all seemed to be carrying guns. Most of them openly having them tucked in their pants, others with tell-tale bulges at the small of their back, a few even carrying shotguns.

It was only when she caught sight of the big posters on the walls of muscled men wearing similar outfits and expressions of angst that she relaxed.

"What are we doing at a fan convention, Castle?" She asked, putting two and two together.

Instead of getting curious and asking how Kate knew anything about cons in the first place, Castle gave a distracted, "Mmm-hmm," his eyes locked on something on the other side of the room. The some "thing" actually turned out to be a some "one".

They approached a smallish man with a scruffy beard in a t-shirt and jeans with a wrinkled sport coat. He was talking to two guys, dressed in the jeans, work boot and plaid variation of the other people, but that's where the likeness ended. These guys were tall, strong and held themselves with confidence - the nervous expression on the man's face showed that their words were just as menacing as their expressions. Kate's eyes narrowed. What exactly was Castle getting himself into this time?

"Chuck," Castle said to the short scruffy guy, hostility dripping off of his words.

The man, Chuck, looked over and he lost his anxious look, instead narrowing his eyes at Castle.

"Dick," he said, just as disdainfully.

Castle twitched a little before saying through gritted teeth, "I prefer Richard, as you well know."

"I'll try to remember that," Chuck said with obvious insincerity. "It's been a while. I must've forgotten."

Meanwhile, one of the two guys Chuck had been talking to moved closer to Kate. When she glanced over at him, he gave a half smile and a wink.

"Authors, huh? Crazy bastards. I'm Dean, by the way. Maybe I could buy you a drink while they get their panties unbunched."

Kate pulled her jacket to the side, revealing her badge. "Detective Kate Beckett," she said with a fake smile. "I think I'll pass."

Dean put his hand up a little and gave a nod.

"Nothing cock blocks like a shield," he muttered, walking back over to the taller guy.

"The last time I saw you, you were shouting in my face that you had the power of God behind you and would sick an archangel on my ass to 'smite me' for my mediocre writing," Castle was saying to Chuck when she turned her attention back on them.

"I was a little drunk," he said looking abashed for a second and shooting a glance at the two guys standing off to the side before turning an accusing look back at Castle. "And I seem to remember you claiming you had a beautiful cop under your thumb that would set me up for murder if you asked. Saving the world from ever reading about Sam's whining again."

The guy that had hit on her snickered, then added. "I completely approve of that plan."

What kind of 'fans' were these guys? And 'under his thumb'? Kate shot a death glare at Castle that promised they'd be having a talk later.

"Also a little drunk…" Castle muttered with a glance at Beckett. "And we're getting off topic. I'm not here because of any of that. I'm here because I got a call from my daughter this afternoon. In tears. After reading your newest Supernatural book."

Chuck flinched a little, but his slightly panicked glance wasn't directed at Castle's anger, it was aimed at the two men to the side.

"You're still putting those out," the bigger guy sputtered in disbelief.

"This freakfest and the books? Man, you are seriously asking for it," the other guy said, his voice going from joking and friendly to low and threatening.

"Come on! The story was there and I was broke!" Chuck said pleadingly, backing away from the two men. "And see, people still want to hear about you- uh, the adventures of Sam and Dean. It's powerful stuff. Teaches good moral lessons and all that."

Whatever was going on between the writer and the two big men was getting more and more interesting, but Castle didn't seem to notice - for once the subtle nuances he was so great at catching were lost on him. He stepped forward and stopped Chuck's retreat by grabbing the front of his rumpled jacket. Kate had been watching the other two, wondering about their reaction, but seeing Castle actually putting his hands on Chuck jerked her attention back to him.

"Castle," she warned.

"Good moral lessons?" He spat, ignoring Kate. "You just turned my daughter's favorite character into a lying, murdering douche bag."

"Cas?" The shorter guy asked, his anger melting into surprise in an instant. "He has fans?"

"Of course he does," Chuck said. "He has just as many fans as the two of you actually. He's a good looking angel with soft spot for humanity and a constantly tortured and torn personality. He carries more weight than Dean and has all of Sam's angst, refined down to perfection. Chicks go crazy for that stuff."

"We're not even going to get into what you did with Cas, he happened to be my favorite character," Castle said, then looked a little embarrassed at his admittance. He shoved Chuck away and went on quickly. "Her favorite character was Dean."

"You turned me- Dean, into a murdering, lying, douchebag?" The shorter of the two asked in outrage.

"He did," Castle said. "Spoiler alert - he had Dean kill Sam's childhood girlfriend in cold blood because she was a 'monster'. After he promised he wouldn't touch her."

Both men had gone dead white. The taller one's head swiveled so slowly and stiffly to look at the other one that Kate wouldn't have been surprised if she'd heard creaking.

"And he's turning him into an alcoholic. Because, you know, everyone wants to watch their favorite character turn into a drunken asshole."

Chuck had been watching the two guys on the side carefully, but at that he turned to Castle looking pissed.

"If you're familiar with the books, then you know it's not in Dean to let monsters walk away after they've been killing people. If he had, then people would be whining that he was out of character."

"Don't give me that crap, I've been reading the books, too. You've been slowly and steadily turning Dean more and more dickish with every volume. People get invested in these characters - they get upset when you have one of them suddenly turn into a cold hearted bastard."

"You mean like when you had Derek Storm kill his mentor?"

Castle sputtered, "That was different! He was having a crisis of identity. He was taking out his self-hate on him because they were so similar. He was the reason Derek was the way was."

"Sure, it's easy to say that NOW. Justification after the fact is always the weak way out," Chuck said, rolling his eyes. "I can't believe your fans bought that load of crap."

But Kate had stopped paying attention to the squabbling writers anymore. Her focus was on the two strange men. The tall one looked shocked and betrayed, but it was edging into anger. Which, with someone his size, wasn't something she really wanted to experience. It could get messy…

The other one looked nothing more than guilty. His eyes were glued to the ground, shoulders hunched.

"You killed Amy?" The tall one asked, his voice deceptively soft, but the shaking of his clenched fists revealed he was barely holding it together.

"Oh, I left out the best part," Castle went on. "Her kid saw the whole thing and Dean threatened to kill him next if he ever caught him killing people. I think Alexis is traumatized. Seriously, Chuck. Not cool. Wait… 'You'? Man, you guys really get into this role playing stuff, huh?"

The two guys weren't paying attention to Castle though. The tall one looked like he was about to be sick and just walked away, leaving the other one to trail after him with a plaintive "Sammy, wait…".

Kate, in the meantime, was fed up. "Did we seriously come here instead of going after an actual murder suspect so you could argue over fake people?"

Castle looked over at her as if he was just now realizing she was there.

She threw her hands up. "The whole papa-bear thing is nice. Castle, really, but Alexis doesn't need you to go threaten authors because something they wrote upset her. And I think she'll agree when I tell her about this."

Kate spun on her heels, leaving the insanity behind her. Let those weird guys pretend they were characters out of a book, let the authors argue over whose writing was better or worse - she had real dead people and real murderers to deal with.

"Wait, wait! You can't tell her," she heard Castle shouting as he scrambled after her. "She'll kill me!"

She shook her head, but hid a smile. He may be a best-selling author and a protective parent, but part of Castle would always be a little boy afraid of getting in trouble when he did something stupid. As annoying as it was, it was also kind of cute. And thinking that probably made her just as much of an idiot…