AN: Due to events in the S4 Finale, this story has now become slightly AU, and so I took it upon myself to bring the Prank War to the end. This will be the resolution, and you may consider it pre-47 Seconds.

The Prank War stretched on for six months. The war escalated to draw in several members of the Twelfth. Both Team Castle and Team Beckett began growing suspicious, keeping watch for the inevitable strike that their enemy would make. Coffee was checked and rechecked from all angles. Conversations became heavy with meaning. Cases and information had to be taken carefully, for fear of tampering. Most members of the Twelfth brought in their own food and drink, not trusting the freely available snacks. Castle had played the 'PR Campaign' card again, making the Twelfth the only Precinct that ate healthy, leaving all those donuts untouched.

Paranoia grew as both sides grew more comfortable and more elaborate. Ordinary things like aftershave or makeup became suspect; closely followed by personal items such as bedding and chairs, and light switches.

All handshakes stopped as outside agitators got into the act, using the old standbys such as whoopee cushions and hand buzzers. No doors were closed properly in expectation of tripwires.

None of them thought these measures were in any way excessive, having been gradually introduced to them over the course of months. The pranks themselves changed, becoming completely ridiculous. Nobody noticed at first, but little by little it was taken one step further after another, both combatants raising the stakes, kicking it up a notch with every passing week.

As the sun set on New York City, Richard Castle adjusted his clown shoes and flip-flopped his way out of the cab. "Sorry about the paint." He said to the driver. "You can make the cleaning bill payable to the NYPD."

"Thanks." The driver said without gratitude. "No offense mate, but if I ever see you waving for a cab, I'm going to ignore you."

Castle nodded as his shirt started leaking bright red paint from a patch over his heart again. "Dammit." Castle complained. "Every five minutes on the dot it starts spurting again."

The cabbie didn't respond to that before speeding away.

The doorman at the entrance to Castle's building was as unflappable as they came, even by New Yorker standards. So when the wealthiest member of the building came in wearing large clown shoes, and bleeding from an apparent bullet wound to the heart, he didn't blink.

Castle looked quietly furious. "Evening Jeffrey. I'm afraid I don't have my key."

Jeffrey nodded. "Do I need to change the locks?"

"No; I'll have them back in twelve to thirty six hours. Don't ask."

"I won't." Jeffrey said easily. "I'll get the spare for you. Got your revenge planned yet?"

"I have several possible counterattacks prepared." Castle said, non-committal, and then froze. "Why do you ask?"

"Just being neighborly sir." The Doorman responded promptly.

"Y'know Jeff, I remember I told you about the pudding in the pillow plan; and Beckett was ready for that one." Castle narrowed his eyes coolly. "You wouldn't be double crossing me would you Jeff?"

"Now Mr Castle, if I shared private information with anyone, let alone let them into your home while you were out…"

Castle paled; eyes bulging. "I never mentioned my apartment."

"Didn't you?" Jeffrey said innocently.

Beckett fired two shots, and quickly darted forward, working the shattered lock off the large steamer trunk. The second the lock was gone, the trunk flew open. Ryan and Esposito climbed out, looking madder than all hell.

"I'm sorry it took me so long. I couldn't find a key anywhere!" She apologized profusely. They were both twitching and shaking.

Esposito spoke then, but not to her. "Ryan, we never… and Javier Esposito means never, speak of the box again."

Ryan nodded crazily; red as a tomato. "I need a shower."

"Me too." Esposito agreed.

"WHAT?"

"No! Not… After you, I mean." Esposito waved that off.

Ryan looked at Beckett with haunted, tortured eyes. "He put itching powder in there with us." He whimpered and ran off to find a shower, scratching at his clothes like a man possessed.

"How did he get you in the box?" Beckett asked in jaded awe.

"I don't want to talk about it." Esposito said shortly. "Y'know, trying not to writhe all over Ryan while locked up in a steamer trunk, I had some time to think. I kept my sanity by focusing on one wonderful thought. I'm done."

"Done?"

"Kate, you know I'd walk into the ocean for you." He said kindly. "But this is nuts. I've been in combat, I was trained to withstand interrogation from middle-eastern warlords. I came back and I worked vice; spent four years dealing with the freakiest levels of depravity and degenerate behavior that a perverted mind can come up with. Castle and his daughter are just nuts. I'm out."

"Javi…" Beckett said helplessly. "What am I supposed to do with the penguins if I don't have you?"

Esposito almost cried. "I'm sorry Beckett, but I can't take it. I haven't turned a switch on or off in my house all month, I haven't shaken hands, I triple check my food, my clothes, my toilet… I'm under siege, and I can't kill him. If I could just put a real bullet into him, this would have been over three months ago, but this isn't a war I know how to fight." He looked like a six year old refugee.

Beckett reached out and took his shaking hands in her own. "No, Javi; it's my fault. I never should have drafted you guys into this. I'm the one that put you into the line of seltzer fire."

"Detective."

They both turned and saw Gates in the doorway. She didn't look angry, just tired.

"Can I have a word with you in my office?"

Castle came in and kicked off the clown shoes with relief.

"What the hell happened to you?" His daughter asked as the door shut. "How did she get you into a pair of big floppy clown shoes?"

"Roughly the same way I got Ryan and Esposito into a steamer trunk." Castle sighed. "Somehow she rigged my shirt with a squib too. I thought I'd actually been shot for a second there…" He trailed off as he realized Alexis was wearing a big white cowboy hat. "Where'd that come from?"

"Don't freak out." Alexis told him. "If I can take it, you can take it." She took the hat off and shook out her hair… which had apparently undergone a change of its own.

There was a beat as they just looked at each other, her with long green hair so bright it almost glowed, and him with a fake bullet wound bleeding down the front of his shirt onto a pair of clown shoes.

"So." Castle said to his daughter finally. "Any word on our plans for the counterattack?"

"Yeah, the guy at Seaworld says that he can't just loan out the penguins." Alexis told him, pulling the phone message out of her pocket. "He also said that two policemen were there this morning asking similar questions."

"Dammit! Team Beckett beat us to it." Castle sighed as his shirt started dripping 'blood' again, and he went searching through his pockets. "Where is that coming from?"

Alexis helped him wrap up the shirt in a ball before it dripped on the floor. "Now, good news about the rubber skeleton; there's a supplier in LA that will ship overnight. The trick will be keeping the blueberries fresh till it gets here."

Castle nodded, unconcerned. "Well, they won't fall apart from a night in the freezer. Oh, did I tell you? I found a guy who could do a wax model of Elvis."

Long silence as they both reviewed the conversation in their head. "I think we may be getting a little ridiculous." Alexis said slowly.

Castle nodded, most seriously. "I think you may be right. Somewhere around the inflatable dog-Superman, I started to wonder if I was being a little silly."

Alexis nodded. "I had the same thought when I went to nine different stores looking for a zombie-elephant costume that would fit Detective Ryan."

Castle spread his hands helplessly. "Where did we go wrong?"

Gates poured Beckett a drink, and set it on the desk with one hand. With the other hand she absently picked up a long ruler and used it to check her office chair for traps. Finding none, she brought the chair over to sit with Kate instead of behind the desk, and they both sat down. "Detective." Gates said. "The entire Precinct is now made up of POW's. Prisoner's of Whoopee." The phrase was unlike Gates, but spoken with such a soft, gentle severity, that Beckett was left forced with no option but to concede.

"I know." Beckett sighed. "I think this has gotten a little… stupid."

Gates nodded, not angry; she was in fact being very reasonable about it. "I am forced to agree. And as much as I may have encouraged you to kick his ass, this isn't the job the taxpayers paid us for."

Beckett nodded. "Escalation." She said quietly.

"Escalation." Gates toasted, raising her glass to Beckett's. "It seems like a natural progression at the time, but you one-up each other till everyone forgets why. Time to start behaving like adults again."

"I hope Castle sees it that way."

"I don't know about him, but I think his daughter lost her nerve when I put green hair dye in her shampoo bottle." Gates said matter-of-factly.

Beat.

They both cracked up into the mirthless laugh of the damned.

At that time of night, the Precinct was on the night shift. There were still plenty of cops around, guarding the prisoners, watching the monitors. But in the bullpen, it was silent. Even the most work-obsessed cops had gone home. All except Beckett.

She turned as Castle knocked on the desk furthest from her. "Knock knock. You wanted to see me?"

He had a brown lunch bag in his hand, and her eyes fixed on it automatically. "Yes." She said neutrally. "Yes I did."

Castle held up his hands, and the bag with them. "I'm not armed. I checked my joy-buzzer at the door."

Beckett nodded. "I did too."

"Really?"

"You wanna search me?" She dared him.

Castle paused, giving the matter due thought.

"Okay, stop it now." Beckett broke him out of his fantasy. "Castle… somehow, I knew when I found my team locked nose to knees in a steamer trunk, that this had gone too far."

Castle nodded seriously. "Beckett, when I realized how upset I was that you had beaten me to a team of trained penguins, I had the same thought."

This was said with a perfect deadpan; the conversation more like a eulogy than anything else.

"Detective, I think there's something more important than winning this war."

"I do too." Beckett said. "Ending it."

"Yes." Castle agreed. "But, the thing is, I think we should have been paying more attention when it began."

"What do you mean?"

"Well, let's review." Castle said and started counting on his fingers. "The first shot in this little war; the shot heard around the Precinct, was an accidental remark about our fictional counterparts considering parenthood. You responded by making me think we actually had done so. The second round was me going to your father's house. I never told you this, but I asked your dad for permission to keep the prank war going."

"Round two started with you asking my father permission for something involving me?" Beckett repeated, dumbfounded.

Castle nodded darkly. "Round three: You faked a marriage proposal."

Long silence. Beckett licked her lips. "Okay. I don't believe a word you're saying, but keep talking."

Castle nodded. "The tone of this war changed when we involved other people. Alexis, Gates… When the teams expanded, it escalated. But when it was just us… it really was just us."

Beckett felt her heart hammering, but didn't know why.

Castle shrugged. "If we were putting this up on the murder board, you'd take one look at it and jump straight to pretty obvious conclusion about what we were both thinking, even if we didn't realize it ourselves."

"Escalation." Beckett nodded, understanding that much. "A desire becomes a thought, becomes a plan, becomes an intention, results in an action."

"Usually that's how we figure out motive to murder; but what would you think about this?" Castle pressed. "Seriously, look at how this started and… draw a conclusion about what the combatants were thinking."

A look of pain crossed her face. "Castle… I can't. Not like this."

"I got no answers Kate, and I'm not asking for anything. I just…" Castle sighed. "We're really good at not noticing the way we act around each other."

"I guess we are." Beckett agreed. Nothing more than that. She gave him nothing.

Castle held out a hand. "Peace?"

She shook it seriously. "Peace."

Castle opened the bag and pulled out a large coffee and an iced donut. "Guess which one's for you?" He asked rhetorically.

Kate's smile lit up her whole face; and she took the travel cup. "Ohh, you have no idea how good it is to get espresso that I don't have to triple check out of paranoia."

Castle laughed and pulled his pen from his top pocket and clicked the button. Kate's eyes bulged at the sight. Castle glanced around for a moment, and left the pen on the desk. "Sorry, need paper; I left my moleskine at home in case you did something to it."

"Would I do that?" Beckett joshed him lightly.

Beckett lunged across the table as soon as he was looking another way; snatching his pen straight off the desk. "One-Mississippi-two-Mississippi…" She counted quickly and silently as she dumped the pen in her desk drawer, slamming it shut. An instant later there was muffled bang and a flash of light came out of the desk, shining a sudden unnatural flash from the cracks around the drawer.

"Did you hear something?" Castle asked, looking back at her from a few desks over.

"No." She said innocently, and opened the drawer again, putting the pen back where it had been a moment ago. Castle hadn't noticed.

Castle returned to the desk and sat down opposite her, scribbling down a note. Beckett smiled at the familiar sight, picking up her coffee again. Behind her, a trio a monkeys with paper-mache wings came wandering up behind her; leashed to Alexis hand, as the younger green-haired Castle came into the bullpen with a satanic grin.

Rick waved desperately over Kate's shoulder, and Alexis froze, trying to reel the monkeys back as fast as she could without being seen. Beckett hadn't noticed.

"Good to have things back to normal around here." Beckett commented.

"Yeah." Castle agreed.

AN: Thanks to all who have followed the story, I hope you enjoyed it. Read and Review.