A/N: I've had this idea swimming around in my brain for months. I'm not sure if this will remain an one-shot. If I do turn it into a multi-chapter story, though, it won't be for a little while. I need to figure some stuff out first. But I've wanted to explore this aspect of Castle's life for a while now and I love jumping head first into his mind.

I hope you like it. And I hope it's not confusing.

Disclaimer: Nope, Castle is not mine. Yet.

Point of Origin

It had been a very long day.

Castle felt as if his body weighed a ton as he unlocked the door to the loft. Kate had woken him up at 6 in the morning because a body had dropped and he had been working on this case for the past 48 hours. He wished he had listened to his instincts and told her he would sit this one out, that he was too tired.

But he didn't.

He wouldn't waste an opportunity to spend some time with her, doing something he loved to do with someone he had a powerful connection with. He could never say no when it came to her.

So he went.

He wished he hadn't.

The crime scene was in an alley near Central Park. A girl, barely out of her teens was the victim. Crying beside her was a tiny infant, lips blue because of the cold temperature. He had never seen Kate freeze at a crime scene.

He did that morning.

"Beckett?" he handed her the usual cup of coffee, but she didn't even blink. "Kate? What…" he started to ask, and then followed her eyes to the murder scene.

The sound of the baby crying assaulted his ears suddenly and he had no idea how or why he hadn't heard it before then. The girl had been stabbed multiple times, the red of her blood pooling around her contrasting starkly to the patch of snow she had been dumped on and left to die.

It was a miracle that the baby was even alive.

He tore his eyes away from the gruesome scene and looked back at Kate, who blinked and seemed to acknowledge his presence for the first time since he arrived.

"Castle, hi." She said quietly and took the coffee from his hand and whispered thanks.

"Who would do such a thing?" he heard himself ask, a shocked tone to his voice. He had never frozen in a crime scene either and he had seen his share of gruesome murders in the past three years.

He didn't know what made this case any different. But it did.

Shrugging out of his coat, he threw it on the couch and made his way to his liquor cabinet. After a case like that, he needed something strong to numb all these feelings battling for dominance inside him. So he poured himself a dose of scotch and took a sip, reveling in how it burned down his throat, warming its way to his stomach.

They caught the killer. He should be happy about that, but he couldn't bring himself to be.

No child should have to go through that.

"What do you have for me, Lanie?" Kate asked when they entered the morgue.

He couldn't bring himself to look at the victim. She wasn't that much older than Alexis and had had her life stolen from her, leaving her child motherless against her will.

"Time of death looks to be between 3 and 5 this morning. She tried to fight whoever did this to her. See the abrasions in her arm? She fought for her life. I'm assuming she was holding the baby with the other." The medical examiner explained and Kate nodded.


"Multiple stab wounds. She bled out." She said and took her gloves off, leading them away from the victim. "How's the baby?"

"He is still with us. We're waiting on Social Services to pick him up. He doesn't have a single scratch on him. It's a miracle he survived the cold, though." He heard Kate explain and the sadness in her voice. This case was hard on her too. "Castle?" she called his name and he blinked out of his reverie. He hadn't even noticed they had fallen silent.

"Yeah, sorry. What'd you say?" he shook his head slowly and she sighed.

"Nothing, never mind. Come on, let's go. We've got to catch the son of a bitch who did this." She tugged on his sleeve and he let her lead him out of the morgue. "Call us if you find anything new, Lanie."

"You got it." Lanie replied before the door closed.

Once they were out of earshot, Kate stopped and turned to look at him.

"Hey. You okay?" she asked softly, her hand immediately finding his and giving it a comforting squeeze.

"Yeah. It's just…" he sighed heavily and rubbed his face with hands, trying to shake off that strange feeling. "It's just, who would do that and leave a little baby next to his dead mother, you know?"

"I know." She sighed and laced her fingers through his. "Hey, you don't have to stay." She said gently and he knew she knew this case was affecting him more than usual. She was giving him a way out, but there was no way he was going to let her face this alone.

He knew this was affecting her too.

"No, I'm okay." He leaned in and kissed her forehead. "Don't worry."

She looked at him in silence for a few seconds, before finally nodding.

"Okay." She agreed and he let out a sigh in relief. As silly as it sounded, he didn't want her to think he couldn't handle this, that he was weak. "But you can walk away any time you want. If you feel you can't handle it, you have to tell me. Deal?"

He offered her a small smile and closed the gap between them, capturing her lips with his. Feeling her body relax against his, he enveloped her in his arms and gave himself a few seconds to enjoy her presence and her touch.

"You've got yourself a deal, KB."

Settling on the couch, he stretched his legs and rested his feet on the coffee table. The bottle of scotch was within easy access on the floor, next to the couch. He needed to relax and forget all these questions swimming around in his brain. He had never given much thought about his origins or cared to know who he shared his DNA with other than his mother.

This case changed that because what if he was just like the baby they had found on the crime scene? What if he shared damaged genes? What if his fascination with death came from the part of himself he didn't know?

He knew his imagination was getting out of control, but he couldn't help it. Being a writer, his mind could come up with hundreds of different scenarios and now he couldn't help but wonder.

Who was his father and why had his mother never mentioned him?

He walked into the break room the next day and was surprised with a scene that tugged at his heart. Kate was holding the baby close to her chest, singing quietly to soothe him, her back turned to the door.

He silently put their coffee and her bear claw on the table and allowed himself to watch her for a minute. He was aware that she loved kids and wanted to be a mother some day. Although she argued that with the kind of life she led, she wasn't sure she should bring a child into the world and risk leaving them motherless should something ever happen to her. She didn't want her child to go through what she had gone through.

But now, watching her, he couldn't help but wish that they could have something like this someday. Together. He was sure she would make an excellent mother and seeing her with a baby in her arms ignited the desire to share that with her.

"Morning." She broke the silence and he chuckled quietly, walking towards her. He should have known she would notice him watching her.

"Morning, love." He gave her a quick peck on the lips, careful not to disturb the sleeping baby boy in her arms.

"What did I tell you about calling me love at work?" she tried to glare at him, but failed miserably.

"Do it?" he asked innocently and she rolled her eyes with a smile. "I missed you last night." He whispered and she kissed him again after checking no one was around.

"I missed you too. Couldn't sleep." She admitted and walked over to the couch, sitting down slowly so not to wake the baby up.

"Yeah, me either. Got spoiled sleeping with you everyday." He wiggled his eyebrows at her suggestively and she laughed, slapping his arm. "How come he is still here?"

"We're still waiting on social services. Someone is going to come by and pick him up today. Hopefully." She explained looking down at the baby boy sleeping peacefully in her arms, completely unaware of what had happened to his mom.

"Still no luck on his next of kin?" he asked, his arm resting on the back of the couch, close enough for his hands to trail lightly on her arm.

"No." she shook her head sadly. "She had been in foster care her entire life. I hope he has better luck."

"Can we name him?" he asked curiously.

"I'm not sure. He probably has a birth certificate somewhere. It wouldn't be right."

"Do we have any new leads on her killer?" he kissed the side of her head and felt her lean more on him.

"Apparently she had a boyfriend that has a history of violence. Ryan and Esposito are picking him up right now." She looked at him and bit her lip. "He's the baby's father from what the neighbors said." She said quietly.

That last piece of information hit him like freight train. The baby's father. Who would do that to their own child? He thought of Alexis and how he would do anything for her. It was such a strange concept that a man could possibly have murdered his baby's mother and left his child out there in the cold to die, that he couldn't quite grasp it.

It was just against nature in his mind.

A knock on his door startled him out of his thoughts. He took a minute to identify where that sound was coming from and when he finally got up, he felt dizzy. Maybe he had had enough for tonight. Putting his glass on the coffee table, he made his way to the door wondering who could possibly be at that time of the night. It was late, past 1am and both his mother and daughter were upstairs sleeping.

He heard the knock again and opened the door. Kate was standing on the other side, wearing sneakers, yoga pants and a NYPD hoodie under her coat.

"Hi." She greeted him, her voice barely above a whisper.

"Hi." He replied and they stared at each other for a minute, before he took her hand and pulled her to him, hugging her tightly.

He was eternally grateful that she was there for him tonight.

Through that entire day, his mind kept coming back to the same thought. He hadn't thought about his father in years, probably since he was a little boy himself. But now, seeing Kate interrogate the victim's boyfriend and little James' father (they had found his birth certificate when they sweeped her place; his name was James Ian Rutherford), he couldn't help but wonder what his father was like.

Was he still alive? Was he a good guy, bad guy? Why had his mother never mentioned him and always claimed to not know who he was? Was that even really possible?

As he watched Kate get a confession from the observation room( little James entertaining himself playing with the lapel of his jacket), he thought that it took a really cold person to murder someone in front of their own child and then abandon their offspring to a slow painful death next to their mother's corpse.

That thought really shook him. What if his father was someone like that?

He looked down at James and the little boy looked back at him with alert eyes. Placing a gentle kiss to his forehead, Rick wondered if his father ever thought about him. Or if he even knew he existed.

It was a daunting thought not knowing who you shared your DNA with. Not knowing where you come from. He at least had his mother, but growing up without a father had not been the best experience in the world. Although he tried to play it cool, like he didn't care, that fact had always saddened him deep down. Now baby James was going to go through exactly that. Even worse because he wouldn't even know who his mother was either. Because his father had killed her.

He would never know that his father was a murderer. Maybe it was better this way.

Maybe he was better off not knowing who his father was too. What if he was a damaged person like James' father?

Kate entered the room with a tired look on her face and interrupted his thoughts. He looked at her and tried to smile.

"You okay?" she asked, leaning against his side and touching James' hand. He watched as the baby gripped her finger firmly in his tiny hand and how she smiled wistfully at him.

"Yeah." He sighed heavily. "Just, you know. Long day. Difficult case." He shrugged and she looked up at him.

"You sure?" she insisted and he nodded. He didn't want to burden her with his thoughts. Hell, he was trying to get rid of those thoughts himself.

"Don't worry." He kissed her cheek and nuzzled against her neck for a minute. "Do you mind if I head home? I'm exhausted." He told her, hoping she wouldn't question his unusual behavior.

She looked at him confused. "Sure, go ahead." She said slowly, as if trying to judge if he was really okay. "Social service is finally here. I have to give him to her." She gestured at James, who was busy sucking on his own hand, while holding her finger tightly in the other.

"Right, you got him?" he asked after handing him over. Kate wrapped her arms around the tiny boy and hugged him for a minute, before nodding at Rick.

"Good luck, baby boy." He heard her whisper and watched with a sad smile as she placed a kiss on the baby's head.

Now, with her in his arms, he felt all those thoughts crashing back into his mind. All those feelings of rejection and doubt about his father assaulted him from all sides and took his breath away. He hugged Kate tightly, grateful that she was there and could be his anchor to reality. The nagging doubt in his mind was proving to be harder to get rid of than he had previously thought.

He had tried to bury those thoughts about his father back into whatever dark recess of his mind he had locked them away before, but they refused to leave. Not knowing was killing him.

He felt Kate step away from him and lace her fingers through his, leading him back to the couch. He watched as she took in the scene of his half empty bottle of scotch and was thankful that she chose to stay silent this time.

They sat on the couch, his arms around her shoulders and her head on his chest. Minutes passed by in complete silence as he steeled himself to talk. He knew she wasn't going to pressure him; she would wait until he wanted to talk.

"It just made me think, this case." He broke the silence and held her closer to his body.

"Think about what?" she asked, turning her head to look up at him.

"About…" he hesitated, but when her arm encircled his waist and she held him tight, placing a kiss to his chest, he cleared his throat and carried on. "About who my father is." His voice came out in a harsh whisper.

"Rick, you can't possibly compare…" she started but he shook his head.

"I don't know, do I? Mother won't ever talk about him. She claims she doesn't know who he is, but I don't believe that. I…" he sighed heavily and kissed the top of her head before continuing. "It's a horrible feeling not knowing where you come from. I don't know if he was a good person. I don't know if he is alive. I don't know if he even knows about me."

"Have you ever tried to find out who he is?" she asked gently, playing with the hem of his shirt.

"No. I've always tried to not let it bother me. I have my mom, it should be enough, right?" he looked down at her for confirmation, but she only smiled at him sadly.

"I only have my dad and it's not enough." She whispered, her eyes sad.

"It's different, though, KB. You had your mom for a while. You got to know her. I never got that chance." He caressed her cheek, making her look up at him. "I'm not trying to diminish what you went through, love. I guess it's just a different kind of loss."

"I know that, Rick. I'd never thought you felt like this. I had no idea." She kissed his palm and nuzzled his neck.

"Neither did I. Most of the time it doesn't bother me. I hadn't even thought about him in years. But this case, knowing that James will go through this exact same thing – even worse because he won't know his mom either – it made me think. There's nothing stopping me from looking for him, right?"

"No… there isn't." she said slowly. "If it's something you really want, then you should find out. But I think you should talk to Martha first. Maybe there is a reason she's never told you anything about him."

"Yes, but this is something I need to know. For myself. For Alexis. I need to know at least his name." he tried to convince her as much as he tried to convince himself that he was making the right decision.

"Whatever you decide to do, I'll be with you every step of the way. We've got each other's back, right?" she offered him a small smile and he leaned down to kiss her.

"Always, KB. Always."

He kissed her again and when she mumbled she loved him against his lips, he made a decision.

He was going to find out his origins.

So... thoughts?