Chapter two! Hope you like, and please review! :)

Castle had been singing along with the songs the whole ride and was trying every trick in the book to get Kate to join in.

"This is my favourite Christmas song. What's yours? How about you sing a line!" Castle smiled at her, and she ignored him.

"Oh, come on. Just one line. Please?" Castle whined.

"We're on our way to a crime scene. I am not taking part in your joyous mood," she grinned smugly towards Castle.

"It's not like the victim is going to know anything," Castle said bluntly.

"Rick!" Kate hissed.

There it was: Rick.

"Sorry," Castle muttered. "How about we make a deal?' he quickly changed the subject.

"A deal?" Kate figured this could go one of two ways but decided to entertain Castle.

"Yes. If I can make you laugh, you have to sing a song with me."

"Seriously? All I have to do is not laugh?" Kate was stunned, and thought she had this in the bag.

"You underestimate me," he said shooting a glance toward Kate. "Just let me find it."

Kate glanced over to see Castle skimming the contents of the CD.

"Here we go! Number twelve!"

Castle hit the search button until he came across the twelfth song on the track. Kate heard the song and knew she had her work cut out.

In his best chipmunk impersonation, Castle sang his heart out: "Christmas, Christmas time is near, time for toys and time for cheer. We've been good, but we can't last, hurry Christmas, hurry fast. Want a plane that loops the loop, me, I want a hula hoop."

Castle's voice went up on 'hula hoop' and Kate couldn't hold it in any longer. She burst out laughing causing Castle to let out a squeal of excitement.

"See! I knew you couldn't resist my charm! It's God's gift to me. One would say I'm blessed."

"Where on Earth did you learn to sing like Alvin, Theodore, and Simon?" Kate asked trying to control her laughter.

"When Alexis was really young this song was her favourite song. So I spent one night perfecting the voice. She used to love it when I sang it to her. When the movie came out, the one with Jason Lee, we made a tradition to watch it every year. Although now when I try to sing it to her she gives me odd looks. So, I figured I'd give it a try with you. It worked didn't it?"

Kate nodded her head in defeat. "Pass me the CD case."

Castle obeyed and it was Kate's turn to scan the contents. It took her a little longer since she also had to keep an eye on the road ahead of her. "Number six."

Castle changed the CD to her request and smiled when the first note was played. "I didn't take you for a Mariah Carey fan. This is Alexis' current favourite song, by the way."

Kate smiled and the comment and began singing on cue. "I don't want a lot for Christmas, there is just one thing I need –" Kate looked lovingly into Castle's eyes and was about to continue but he cut her off.

"Whoa! You can sing!?" Castle was captivated by her Alto-Mezzo Soprano singing voice.

Kate just shrugged. "My mom was a singer. I guess I picked up the singing gene."

"You're really good! You do know this increases your hot factor by like six points, right?"

"Hot factor?" Kate giggled. "Well, if I just increased six points, what number am I now?"

"Oh, you're gone through the roof! I don't even think John Nash would be able to count that high! I think Nikki Heat is going to have to go to a karaoke bar with Rook, Raley, and Roach. She'll knock their socks off!"

"As long as Nikki doesn't get super drunk, take off her top, and do a table dance!" Kate shot him a look.

"I'm curious," he said raising an eyebrow, "are you speaking from experience? Because, if you are, then we are so making it a point to go to a karaoke bar tonight."

A brief memory crossed Kate's mind and she quickly fell in sync with now upbeat part of the song. "I just want you for my own, more than you could ever know, make my wish come true…"

Castle noticed this deflection and Kate's voice rung through his head: So many layers to the Beckett Onion. He smiled at the thought, stared into her eyes, and joined in, "All I want for Christmas is you, you baby!"

The two finished out the song, along with Baby It's Cold Outside, laughing and serenading each other.

When they pulled up Ryan and Esposito looked anxious. They got out of the car and Esposito quickly piped up. "Hey, what took you guys so long?"

"We traveled through the seven levels of the candy cane forest, past the sea of swirly-twirly gumdrops, and then, we walked through the Lincoln tunnel." Castle was grinning from ear to ear.

"Ignore him, he's on some kick about Elf, and I assume that sentence is somehow related." Kate just shook her head with a blank look on her face.

"Beckett, whoa! Don't dis Elf! That movie is classic!"

"So, you too huh?"

Ryan shrugged. "It's really funny!"

"Why thank you detectives Ryan and Esposito," Castle took a quick look at Kate, "It's just nice to meet other humans that share my affinity for elf culture," Castle teased which sent the boys into a roar of laughter.

"Focus guys, crime scene. What do we have?" Kate was back into cop mode.

"Kara Smith found the body. She says she was walking her dog when the little guy took off and sniffed him out. CSU are currently bagging evidence. Now that you're here, Lanie said that she found something." Ryan pointed to where Lanie was crouched down obstructing the view of the body.

All four adults walked over to see a middle aged man dressed in a red velvet suit with white fir trim with a matching hat. John Doe was also sporting a white beard, spectacles, a black belt with a shiny gold buckle, and a pair of black boots.

"Someone killed Santa!?" Castle screamed.

"I guess someone must have gotten coal in their stocking," Esposito replied in true Castle fashion.

"Well it's obviously not the real one," Castle scoffed, "he's busy making toys." Castle received odd looks from the fellow detectives standing before him.

"Dude, you can't be serious?" Ryan looked at Castle in amazement.

"As a heart attack."

"Was there an ID on the body?" Kate asked ignoring Castle.

"Nope. But we did find this a few meters from the body…" Lanie trailed off as she held up a giant gold bell.

"Considering his dress, and accessories… my guess is he's a mall Santa." Esposito said matter-of-factly.

"Mall Santa?" Castle interjected, "He only looks to be about twenty. Maybe twenty five at latest. Most mall Santa's I've seen aren't young men. They're usually old and overweight."

"Hey!" Ryan shouted, "My uncle's a mall Santa!"

"And, what does he look like?" Castle glanced at Ryan.

Ryan just looked down, telling Castle that he was right.

"Exactly," Castle said proudly.

"Well, now that we have that all straightened out," Kate said mildly agitated, "What do we have Lanie?"

"Male. Late teens to early twenties. It's obvious there was blunt force trauma to the head. However, there are three bullet wounds." Lanie pointed them out and continued, "From what I can see, this one did him in. It seems that the head injuries are just for show. Or the killer new the victim and he wanted to make it extremely personal. I'll be able to know more when I do a full examination."

"Okay," Kate nodded, "Ryan, call around the malls or any other place that would have hired a Santa. See if someone never showed up for work."

"On it boss." Ryan and Esposito turned and made their way to the squad car.

"Come on Castle, let's go." Kate motioned for Castle that it was time to head back to the precient.

"Where are we going? To get you a slutty elf costume?" Castle grinned.

"NO!" Kate shouted much louder then she had intended. "You are going back home, and I am doing paperwork until we get a lead. I'm sure you have some Christmas cheer to be spreading."

"Elf costume?" Lanie questioned.

"For my Christmas Eve party. You're invited, by the way." Castle couldn't stop smiling. "You could get a slutty elf costume too! You could be twins!" Castle's eyes lit up. "This is great inspiration for a Christmas novel. Nikki Heat and Lauren have to go undercover and –"

"Castle!" Kate hit him, "unless you want to be sleeping on the couch tonight, you had better not finish that sentence!"

Castle sensed Kate's sarcastic tone. "Hey, it's my house: I can sleep wherever I want. You don't technically live there, remember? You're still trying to sell your apartment," Castle replied playfully.

"Well you can sleep alone and I can stay at my apartment tonight, if that's what you want?" She teased him.

"Point taken, sweetie." Castle emphasized the term of endearment to watch Kate squirm. She hated when her romance was publicised in her work environment. "Well, you're still invited Lanie. And Christmas attire is mandatory."

Lanie nodded. "I'm going to see some friends, but I'll stop by for an hour or two."

"Great!"

"Bye!"

"Don't forget about that twin thing!" Castle's boyish grin was back.

Lanie did Kate's signature eye roll as she watched the pair walk towards the Crown Vic and drive off.

A/N: At first I had it written so Alexis was babysitting and the child loved the movie. However, after doing some Googling I found that the Chipmunk song was actually written in 1958. Considering the song was obviously around before Alexis was born, I figured I'd go with the story that's mentioned now.

I chose to have Kate pick Mariah Carrey's All I want for Christmas Is You because I wanted it to be something sweet, upbeat, and a little romantic too. After skimming my Christmas playlist, I figured this song fit nicely with Stana's voice. If you haven't heard Stana sing, you should check out The Librarian: Curse of The Judas Chalice. She has a fabulous voice!

Also… the John Nash reference. For those of you who are unaware, he was a famous mathematician. There's a movie titled A Beautiful Mind, based on him, which starred Russell Crowe. It's an amazing movie and I highly recommend it to anybody.