Summary: Beckett and Castle investigate the murder of a Transgenic. Total AU. How will they react to the news? Where will their investigation turn? Will they finally come to terms with their feelings for one another?

Author's Note: Hey guys! This is my first Castle Fanfic. If they are not totally in character, just understand that this is FICTION. Hopefully, I will do them some justice however. This story has been in my head for a few days now.

By the way, has anyone seen the sneak peaks for To Live or Die in L.A.? The one in their hotel suite? Can anyone say OH EM GEE? I'm depressed because I have class that night but I will be sure to watch it the next day.

Please R & R. Let me know where you'd like to see this story go.

Disclaimer: I do not own Castle and their characters.

Unknown DNA

RRRRRIIIIINNNNNNNGGGGGGGG!

The shrilling sound of her cell phone startled Detective Kate Beckett from her much needed slumber. For the last two weeks, she had been on an extremely frustrating case. Just yesterday morning, they managed to catch the killer and have a confession by the end of the day. It was a relief to the entire team so they all went out for celebratory drinks at the Old Haunt and retired by 11:30pm.

Lifting her head up to take a peak at her alarm clock, she noted that it was only 3:37am. She reached over to the nightstand and fumbled with her phone before pressing it to her ear on the third ring.

"Beckett."

She said with an incredibly sleepy voice.

"We got a case."

The detective groaned in response and wrote down the address before hanging up. Her head flopped back in frustration, pulled a pillow to her face, and screamed in it. Normally, after a particularly hard case, the team was given a few days off. So why were they calling only hours later?

Yawning and stumbling out of bed, she made her way to the bathroom to get ready. Within 20 minutes, Beckett was dressed and securing her gun in its holster. She ran her fingers through her hair to tame the mane before finally putting on her mother's necklace along with her father's watch.

Beckett contemplated whether or not to call Castle. He barely had any chance to sleep, having stayed with her whenever she remained at the Precinct well past midnight. He took care of her, knowing that she sometimes forgot to eat when a case was too rough. She was dedicated and committed to finding the truth. Over the last few years, she's come to depend on Castle's presence. He was her bright light at the end of a very dark tunnel. He made her job a little fun and has been surprisingly insightful into the criminal mind. She trusted him as her partner and with her life but did she trust him with her heart?

Opting to give him a call, she pulled out her phone and hit number '1' on speed dial.

"Mhm Castle."

He said sounding groggy and barely awake.

"Hey Castle. We've got a case."

Beckett instantly regretted calling him. She knew how little time he has spent with Alexis and his mother. His lack of sleep was beginning to wear on his, much as it has on her.

"What? Already? I thought you had the weekend off?"

"Crime doesn't stop just because we would like to get more sleep. Listen, if you don't want to co-"

"I'll be there. Just text me the address."

Kate could not help but smile and slide the phone back into her pocket. Despite everything, Castle was reliable as ever.

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Stepping out of her car, Beckett caught sight of Castle heading her way with two Styrofoam cups of coffee. Green eyes looked into his blue ones with so much gratitude.

"How do you get here before me and with coffee? Thanks."

She said before bringing the cup to her mouth. She tested the temperature quickly before taking a large gulp of the much-needed cup.

"What can I say Detective?"

They then both turned and headed over to Lanie who was kneeling next to the victim. A dumpster was pulled away from the brick of an apartment building.

"What've we got?"

"Caucasian male, mid to early twenties."

"He's just a kid."

Castle said with a hint of sadness. He could not be much more then 6 years older than Alexis. The victim was wearing a black shirt, a leather jacket, and jeans. He suddenly felt the urge to go home and hug his daughter but brushed it aside.

"Cause of death?"

He asked.

"From what I can tell, a broken neck. Based on the temperature of his body, I'd say it happened between 11:30 pm and 1 am."

Lanie took a moment to glance up at the two of them, wondering why they were requested to be on the case. It seemed fairly standard.

"ID?"

Beckett asked. Just then Ryan and Esposito walked up and stood by Castle.

"No wallet or ID. Residents said they did not hear nor see anything. Could be a robbery gone wrong."

Castle then knelt down next to the body as well, staring at the clearly broken neck. His eyebrows furrowed as he got the look that something did not add up.

"What?"

Kate asked, all too familiar with that look.

"How strong would you have to be break a neck nearly in half and almost rip the head off?"

"What are you getting at Castle?"

"You'd have to be pretty strong. The head looks as if it was almost completely taken off the body. He's extremely healthy looking and strong. I'd say the military judging by his haircut and physique."

"The bruising on his neck would suggest that someone's hands might have done the job. But I will know more when I get him back to the morgue."

Lanie cut in before Beckett then turned to the two detectives.

"Who found him?"

"Homeless guy, Fred Miller. Found the body behind the dumpster when he was digging through the trash."

"Anything else?"

She directed her question to Lanie. When she shook her head she turned from the body and back to Ryan and Esposito.

"I want to talk to Mr. Miller. Send uniforms to canvass the area to see if anyone saw anything out of the ordinary. Look through missing persons and see if we can ID our vic."

"Right on it."

Ryan said before they both left. Castle then turned to Beckett.

"I don't get it. Why would they call you in for this?"

"I don't know Castle. Come on, let's talk to Fred."

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Author's Note: I should have the next chapter soon. Hopefully, it will be much longer! Don't forget to make my day and review! Also, if anyone wants to gush about "Caskett" just send me a message :D