A/N: I don't own Castle… or the plot for this chapter. So, the author youdude mentioned in an author's note that she was considering writing for Castle. I messaged her asking if she would write a Castle version of her Criminal Minds fic 'Cookies and Lollipops'. She understandably said no, but then! Awesomely, she said I was welcome to. She has read and approved this, so… Please don't think I'm ripping her off.

The premise is the same, but obviously after this chapter the two fics are going to be completely different, being about different shows and all.

Review, and I write faster!

XXX

He could feel the one of the officers breathing behind his shoulder. Damn, that guy needed a breath mint.

Or four.

Trying to ignore the thoughts of the garlic-y food that the officer had no doubt eaten just hours prior, Esposito glanced over at Beckett over the top of his gun, immediately starting forward when she motioned to him with two fingers.

She was so ridiculously focused, he mused, comparing himself to her as he quietly made his way over. There was no way that she was doing anything but think about the suspect.

Which is exactly why she's the most successful homicide detective in the precinct, he reminded himself. Well, that and her eye for details, which-

Focus, Esposito.

He raised an eyebrow at her in question, and she gestured around the door frame. "There's a corridor around the corner with about five doors and a stairwell," she whispered. "I'll cover the stairs while you and pizza-breath down there check the doors."

As she left, a smirk spread across his face.

So she'd noticed, too.

"Yo." He called to get the officer's attention. "She's got the stairwell, and we gotta check the rooms. Let's go."

It took them under 30 seconds to ensure that each of the five rooms on the floor were empty. They were searching for murderer Damien Shaye in a run-down apartment building, slated for demolishment. Good thing, too. It had been left to rot for over a decade since nobody was interested in renting out single rooms- and who could blame them?- and now mostly housed the odd squatter for a couple of weeks a year.

"You got anything?" Beckett hissed down the corridor, her gun trained up the stairs. When he shook his head, she nodded. "Okay. You two go up to the second floor; I'll meet Castle and Ryan on the third, see if they got anything."

Esposito smirked again. Yeah, right. She'd been waiting for the first opportunity to go re-join Castle, having very reluctantly let him out of her sight in the first place. Her desire to find them was not unexpected. Said something about her trust in Ryan's shooting-and-protecting skills, too.

He filed that little nugget away in the back of his mind to torment Ryan with later.

On the second floor, her and Officer Pizza-breath has just finished searching the rooms when a gunshot pierced the silence.

There was silence for a moment before they heard a shrill scream.

"Kate!"

Esposito's heart dropped. He started to move-

Two more gunshots.

Ryan. Castle. No.

He heard thumping, screaming, Ryan yelling, and rushed up the stairs, quickening his run. "Move!" he yelled behind him at the officer, who was standing stock-still. "Don't just stand there- let's go, move!"

He burst into a room on the fourth floor- why didn't they wait? They were supposed to be on the third floor- following the source of the noise. When he shoved the door open, he stood unmoving for a moment, taking in the scene. Ryan had a man cuffed and pinned to the wall, and was shouting unintelligible phrases at him. Blood was dripping from a wound on the man's arm.

"What happened?" Esposito asked urgently, approaching his partner. "Hey! What happened? Who got shot?"

Ryan dropped the man- who was, they could see, Damien Shaye- and turned to face him. "I- I think Castle and Beckett. We hadn't finished clearing the rooms, and Beckett came and took Castle with her, we split up… I heard the shots, ran up and chased Shaye to this floor, gave him a bullet to the arm but I don't know what-"

Ryan seemed to snap back into reality and stopped suddenly, glancing around the room. Esposito too looked around frantically as both he, Ryan and the officer ran out of the room and down the stairs to the third floor.

"Beckett!"

"This is Detective Ryan, NYPD, we need an ambulance-"

"Castle! Can you hear me?"

"-most likely an officer and one civilian down-"

"Are you hurt? Castle!"

"-one more civilian definitely shot in the arm, other two unknown-"

"Beckett!"

"I found something!" The officer's voice rang out amidst the chaos, and Ryan and Esposito hurried towards him. He was kneeling in front of a large table, holding up the huge white lacy tablecloth draped over it.

"What?" Ryan barked out, phone still held to his ear. He had no time for this- Castle and Beckett could be shot. Castle and Beckett could be dead.

"Two kids."

That stopped him short. He put the phone down and approached the table, bending down to see two furiously-blushing children, one girl one boy, drowning in material. Ryan put a hand on the girl's arm.

"Hey… hi, don't worry. Are you okay? You're not hurt, are you? Listen, we need to find our friends. Did you maybe hear or see any-"

The girl shook her arm out of his grasp. "Relax, it's us."

The officer started choking- probably on his own spit. Esposito took a step back.

Ryan scrambled away from her, knocking over a chair and tripping over his own feet in the process.

"Beckett? What? But… how? You- you're… what? Beckett?"

Now that he looked, he could see it. Esposito slowly approached, and pulled both children into the light to see them better. Castle was holding up his pants with one hand, stumbling like a little drunk person every time he tried to move. Beckett stood in simply her white blouse, which was more like a dress given that it reached past her knees. She stumbled over her too-big shoes as Esposito dragged them both forward, her light brown curls swinging into her eyes.

"Stop doing that!" she complained, the eternal boss.

He pulled his hands back. "What the hell happened to you?"

"He… shot us, I think, with like these dart things," Castle explained slowly. He didn't look at all upset- on the contrary, he was grinning like a madman.

"And he didn't have a gun, so he couldn't shoot Shaye when I went down," Beckett admitted moodily, annoyed that her refusal to allow Castle a gun had come back to bite her in the ass. Oh, well. If she had to be turned into a kid, then so did he.

Castle nodded, seeming unfazed. "Yeah, and then he shot me too! Isn't this amazing? It's like a sci-fi!"

The three adults in the room nodded once, slowly. Then Ryan snapped into motion.

"You two grab those bottles and the dart gun," he directed, before grabbing one of each of the children's arms. "And you two, let's go."

Neither of them could walk. After a few minutes of bumper cars, Esposito had had enough. "Here." He thrust his pile of bottles at the officer before reaching down to scoop up Beckett. "Come on."

"No!" She slapped his outstretched hands away. "You're not carrying me!"

"Please, Beckett?" he asked, figuring it would be better to let it be her choice. "We have to get you to a doctor as soon as possible, and you can barely walk straight." You can't walk at all, let alone walk straight, he amended in his head. When Beckett nodded reluctantly, he congratulated himself on a job well done, and, swiftly picking her up, motioned for Ryan to do the same with Castle.

Castle was having none of it. "Nu-uh. If you're giving me a ride, you're gonna do it properly."

"What do you mean?"

"Bend down," Castle directed. When Ryan was crouched in front of him, he clambered onto his back. "Now, giddyup, slave!" As they slowly made their way down the stairs, he turned to face Beckett, grinning. "Isn't this awesome? And you know, if you'd just ditched your boots, you'd be able to walk I think."

Her scowl deepened, and she tightened her hands into fists.

…

They'd been at the hospital for hours. Hours.

"What the hell are they doing in there?" Esposito finally exploded after the fourth hour, striding over to the receptionist. Gates, who had come to join them at the hospital, shot him a glare.

"You are representing the NYPD and you will behave as such," she hissed at him. "We don't want to ruin our reputation."

Thankfully, she turned away and missed his gesture in reply.

Almost an hour later, a doctor finally emerged from the testing area. "Katherine Beckett and Richard Castle?"

"Jesus, finally!" Ryan nodded at the doctor. "What's wrong with them?"

The doctor, a stout, middle-aged man, motioned to them to follow him. "Benjamin Daniels. I'd like to take this somewhere more private."

They followed him to his office, where he shut the door behind him slowly. "Take a seat, please." He waited until they were all seated on hard plastic chairs. "Now. Down to business. I can't say I've seen anything like this before."

"We brought a some bottles...?" Ryan started.

"We'll need to run extensive tests on all three bottles before we can give it to them. If it's the wrong substance, it could quite easily kill them. I'm sure you understand."

"Yeah, sure. But how long will that take?"

"Depends. If we need to send it to another hospital, up to three weeks. Otherwise, one to two weeks."

"Three weeks?" Gates exchanged looks with the other two. "What are we supposed to do with them for three weeks?"

The doctor's eyes met his, and Gates was surprised to see that he was amused. "It could be only a week, ma'am."

"Sir."

"Excuse me?"

"I prefer 'sir'."

"Uh…right. Well, anyway, sir… now, I need to talk to you about their...mental health, if you will."

"He's damaged their brains?" Esposito was furious. "When I get my hands on that son of a bitch he won't know what-"

"Esposito!"

The doctor shook his head. "No… Esposito, was it? They just have some...issues. See, as I'm sure you've noticed, they hold all their adult memories, as well as their adult knowledge. However, after extensive testing with the hospital's psychologists, we've concluded that they have the emotions, fears, needs, motor skills, taste buds and attention spans of a child their respective ages."

"Which are?"

"Although they look slightly younger, Katherine is physically almost five, and Richard is seven. Now-"

"What?" Gates cut in sharply. "How exactly can they look a certain age, but physically be a different age?"

"Oh, it's nothing to worry about," Dr. Benjamin replied. "They're just small for their age. By physically, I meant their bone and organ development as well as their teeth. Richard is missing a tooth, you might have noticed when you brought him in."

Ryan looked up. "Wait, four and seven? What, did Beckett get hit with more or something?"

"Actually, the girl received a little less."

"She's younger," Gates said quietly, catching on.

"Yes." The doctor agreed. "Now, what I wanted to talk to you about was what I mentioned earlier. Their emotions, attention span, needs, senses, and critically, their logic, are that of a child; however their knowledge is that of an adult."

"Which means...?"

"They won't like coffee or vegetables, for one thing." The doctor chuckled. No one else did.

He quickly continued. "As for the rest...Okay, well, let me give you an example. Say, you give one of them a lollipop, or tell them that you're taking them to the beach. How would you say a normal child would react?"

Both Ryan and Esposito naturally looked to Gates for the answer. She glared at them, but answered anyway. "I would assume that a normal child would be happy. Maybe run around shouting or jump up and down."

"And your detectives," -Gates didn't correct him on Castle's position- "would want to do these things, but they wouldn't, because they have the knowledge that says it is inappropriate for a police officer to run around the precinct screaming. However, as they have the logic of a child, they won't be able to figure out why. They'll just know they can't."

"And that's a problem?" Ryan asked.

The doctor nodded. "Children are prone to extreme emotions. Your detectives, as adults, are not used to that. They will try to hide or bottle up these emotions, especially feelings like anger, sadness, hurt and others which show vulnerability. Eventually, as the days go on, their adult mind will get used to the emotions and won't think them strange. So after a few days, they will be acting like completely normal children, except that they will be unbelievably intelligent."

"So we treat them like kids?" Esposito asked.

"To a certain extent, yeah. However, you do have to remember that they are adults and they will not appreciate being treated like babies. Katherine was pissed off at being carried."

Esposito nodded, but then paused. "Wait, I don't get it. Why would they want to hide their feelings?"

"Because they have no control over them. Imagine you, with your mind, were put into the body of a child and suddenly when anyone said anything to you, you immediately felt strong feelings, whether they were positive or negative. Another example: you tell the kids that you'll buy them a cookie, and you forget. You tell them that. As adults, they'd understand. As children, they know, thanks to their adult knowledge, that what they're feeling is irrational, but they can't help but feel angry or hurt because of their child logic which doesn't explain why the feeling is irrational."

The doctor paused. "To put it simply, they'll know that they shouldn't feel what they're feeling, but they won't understand why, so they can't make that feeling go away. Eventually, their child logic will win over, and in a day or so they'll ignore the adult part of the brain that says 'It's irrational to feel this way! He forgot! It was a mistake!"

"What?" Esposito was startled. "They won't listen to their...adult knowledge?" Dr. Benjamin nodded. "Why not?"

"Because," the doctor explained patiently, "it would be like me telling you to accept that the moon is made of cheese. I'm presenting it to you as fact. Do you believe it?"

"No."

"Why not?"

"Because simple logic would tell you that it's not..." he paused. "Oh. Point taken."

"So they could throw tantrums?" Ryan cut in.

"Possibly."

He and Gates simultaneously paled. "Oh, no."

Benjamin Daniels chuckled. He was getting way too much entertainment out of this, Ryan thought.

Gates, always logical, leaned forward. "You mentioned fear."

"Oh, right. Yes." Dr. Benjamin suddenly looked grave. "That might be a slight problem. Any fear that they had as an adult- of, say, a certain killer will be a hundred times worse."

"Why is that?"

The doctor replied, "They will, as I said before, have their memories, so they will know and remember each and every killer you have come across. They will remember the victims, the murders, the crime scenes, any traumatic experiences...everything. All of these memories, in a child's brain. I definitely wouldn't want to be them. That's something else that you have to make sure they don't try to hide from you- when they get scared. Also, they'll have regained any childhood fears, like a fear of big slides at the park."

"Okay." Ryan ran a hand through his hair. "Slides. That we can handle."

"Can we just go now?" Esposito begged.

"Of course," the doctor smiled. "Let me just get the children for you. Don't obviously treat them like kids. And be patient with them. It's only for a little while"

He returned moments later with Beckett and Castle in tow, both of their clothes rearranged, courtesy of a kind nurse. They were both only wearing their shirts, and they each had a man's belt around their waist, making them look like they were in dresses or tunics.

"Good work," they heard Dr. Ben tell the nurses. He passed Castle and Beckett some sheets to sign, which they did, albeit shakily. Once all the paperwork was finished, they started to leave.

As they were walking out, they saw Dr. Ben slip a lollipop into each of their hands. Beckett pretended she didn't care, but Ryan smirked as he saw Castle quickly unwrap and pop the lolly into his mouth. Beckett looked longingly at hers, but refused to give in, and stoically followed Gates to the car.

Esposito shook his head, staring at them both. We have our work cut out for us, he thought grimly.