This story is AU, so if that isn't your thing I'm sorry. Please Enjoy and let me know your thoughts as I am extremely nervous about posting this!

Rated T for now.

Disclaimer: I do not own Castle, this is simply just a hobby.

"Morning guys" Castle chirped as he walked into the 12th. Himself, Detective Esposito and Detective Ryan had just finished a big double homicide case and weren't really expecting to be doing much for the next couple of days except finish off the mountain of paperwork that came with the case.

Castle spent the morning at his desk, buried under half a dozen empty coffee cups and endless reels of paper and evidence that needed filing out and filing. He was just about to break for lunch when he noticed Esposito walking towards his desk holding what looked like an address. He knew he shouldn't really take on another case at this moment, but it was looking to be so much better than filling out endless forms.

"Hey, got a fresh one East 7th street, and it's a freaky one"

Castle couldn't help but be intrigued by the freaky ones. He gave a cheeky smile, grabbed his coat and the three of them made their way to the address.

Detective Castle had been working at the 12th Precinct for five years, originally he had been a writer, writing crime novels however whilst doing research he found that his talents lay more in the field than on the page, and even though his works were good, his talent was finding justice. He had proven himself over the years, built up his character to show that he was more than capable of doing the job. His writers imagination had never left him, he always took an interest in the more unusual cases, his outlandish theories had led them to some of the best breakthroughs they had ever had, building up not only his reputation with his colleagues but also throughout the force.

So when he had heard that this case had the potential to be one of the more unique cases he couldn't turn it down, the paper work could wait; he was never that keen on completing it anyway.

"So what have we got Lanie?" Castle asked as he entered the house, it smelt rotten, flies swarmed in one of the doorways, he took a quick glance and noticed a metal bed frame sitting in the middle of the room. The bare mattress looked damp and dirty, and then he noticed handcuffs attached to the top two corners of the bed frame. He continued to survey the room, not venturing too far inside. It was then he noticed the door to the room, it had a padlock in the middle with dead bolts at the top, middle and bottom, which looked as if they had been fixed on by armatures. He didn't know for sure what had happened here, but he had a pretty good guess.

"Single GSW to the chest" Lanie replied simply, pulling him from his thoughts and back to the reality of the case.

"That's it?" Castle asked, he thought this was a freaky one, suddenly all the images he had racing through his head, popped straight back out again and right now paperwork for the other case was looking more interesting than a simple open and shut case, which would only add to his paperwork pile.

"For the body yeah, but you might want to go and check the bathroom?"

Castle didn't question it he simply followed her directions and made his way to the bathroom. The smell from the bedroom seemed to carry through the rooms, spreading like a disease, contaminating anything it came in contact with.

Dodging the litter and broken furniture that scattered the room he had his way towards the bathroom. The house was in a state, it looked as though someone hadn't left there in weeks, maybe months. The living room; if it could be called that, contained a small armchair that was sunken in on the cushion, the springs clearly gone and in need of replacement. He couldn't imagine the extent of what had happened in this room. The house was only small. The dining room had been turned into the small bedroom that housed the chilling iron bed frame and bolted door, the living room took up most of the downstairs with only a small kitchen unit off to the right hand side. All the windows were covered with bits of newspaper and each door was fitted with a dead bolt across the middle of it.

Turning to the left he knew immediately which room was the bathroom because of the heavy number of uniforms that surrounded the room, as well as Ryan and Esposito who were stood directly in front of the bathroom door.

"Hey, what's going on?" Castle asked, keeping his voice low, noticing how it seemed Ryan had his ear pressed to the door, trying to work out what the sounds coming from the other side of the door was.

"Don't know, when uniforms arrived they said they tried to get into the bathroom but the door slammed shut and bolted behind them, they think they saw a young woman in there but didn't get a good look and now she's sat right behind the door. So they can't just break it down and she is refusing to speak to us, even Lanie tried speaking to her but she isn't having any of it" Espo replied, sighing as it seemed they were getting nowhere.

"Ok. Mind if I have a go?" Castle asked, raising and eyebrow in his typical way.

Castle wasn't exactly known for his soft side but he knew how to handle people well and when it came to it he could be very caring. He seemed to be able to gage when people needed help and when they needed taking down. The boys backed away from the door, Espo waved his hand, a gesture that meant 'do your worst', and it wasn't as if they had been getting anywhere anyway.

Castle leaned in closer, pressing his ear up against the door.

"Mam can you hear me. My name is Detective Richard Castle I'm with the NYPD. Can you open the door please?"

Everyone was silent, waiting to see if the woman had heard or was going to respond. After a few moments they heard a shuffling sound, but then what appeared to be more sobbing.

"You're lying" The woman said in a small voice, she was clearly terrified to open the door.

"I promise you I'm not. I have a badge to prove it. Look if you don't want to come out would you at least think about letting someone in, we just need to check that you are ok?"

There was no reply. Only the sound of small cries seemed to penetrate through the thick wood door. Castle looked to Ryan who shrugged his shoulders. They all knew that eventually she would have to come out, either of her own accord or through another method which none of them really wanted to resort to, if she really was as terrified as she sounded then breaking through the door, or coming in through the window would only scare her even more.

"I know you might be finding it hard to trust me but I promise you, my colleagues and I only want to help you. I'll make you a deal. I will leave my gun out here and will come in alone, but you need to give me your word that you will not try anything, I just want to help you, ok?"

Ryan looked at Castle questioning why he was willing to go into an insecure room unarmed, but he didn't voice his concerns. This wasn't the first time they had been in a situation like this and experience had taught him that working with Castle, no two days were the same and sometimes they needed to break the rules a little.

The team waited for a moment as Castle passed Ryan his Glock 19. The next thing they heard was the door creaking open slightly, only half an inch if that. He only saw a flash of brown eyes and brown hair that covered most of a woman's thin face, the rest of her body was hidden behind the door.

"Show me you badge" she demanded and Castle wasted no time in handing it over to her.

She inspected it clearly, running her slim fingers over the metal and across the badge number '41347'. A tear leaked from her eye before she could stop it. She thrust the badge back into his palm and then pressed her weight against the door again, only leaving enough room so that she could see his face.

"No guns" she whispered and Castle couldn't tell if she was talking to herself or to him.

"No guns, I promise, I'm leaving it out here with my partner. I'm unarmed." He informed her, hoping that he was convincing enough.

He watched as she quickly shut the door, before hearing what he presumed was her dropping to the floor and sobbing again.

"Ok, I'm going to come in. Do you have any weapons on you?" He hated asking, but it was better than him getting in there and then realizing that she only intended to harm him. He listened intently at the door, waiting to see if she was going to reply, or at least be honest with him.

"No" the woman whispered, she almost sounded as if she was shocked that he had asked, like it was some sarcastic comment.

Castle took this as his cue and slowly opened the door. He looked around and saw her sitting on the floor, cradling her knees to her chest with her arms wrapped around them, protecting herself. It was then he noticed that all she was wearing was a dirty over sized t-shirt and her underwear. He quickly shrugged himself of his long coat and wrapped it around her shoulders, it completely buried her covering up her arms and legs. She flinched at the contact and shot her head up as he fasten some of the buttons at the front of the coat, her tear filled eyes looking directly into his.

"Thank you sir" She said quickly, too quickly for Castle's liking, but that wasn't his main concern right now.

He could tell that she had been beaten, she had a large cut on her eyebrow and a quick glance at the mirror on the bathroom wall that was cracked with a smear of blood of it told him almost exactly what had made that cut. Her eyes were sunken and surrounded with dark circles, clearly showing that she hadn't had a decent night's sleep in a while. Her hair was greasy and scraped back into a messy bun with stray head falling to cover her pale face, her cheekbones were showing much more than they should do and her lips were chapped at the sides. He couldn't imagine all that she had been through, or how long she had been there and the colour of her skin told him that she probably hadn't seen daylight in a while.

"What is your name?" he asked gently, trying not to surprise her.

Such a simple question she should have answered immediately, but it seemed to take her a while she looked at him as if it was a trick question. She swallowed before mumbling,

"um – Kate, my name is Kate"

As soon as the words left her lips she looked down and squeezed her eyes shut as if she was preparing for something. Castle couldn't understand this, it was as if she thought she was in the wrong. He knew he needed to get her out of here and then maybe she would feel safer.

"Kate. I need to get you out of here, do you think you can walk?"

"Walk?" she asked quietly.

"yes walk, or do you want me to carry you, if you feel you can't walk?"

"I…" she paused, searching his eyes in case this was some sort of sick trick, but all she found was piercing blue swirls pouring out with concern.

"I would appreciate it if you would let me walk sir" she replied after a few moments of consideration.

Castle really couldn't understand this but he thought it best to just go with it for now. Without thinking he quickly took her arms and helped her to stand up, she jerked and gasped when she felt his hands on her and instantly went to protect herself.

"It ok, you're safe now. There will be other officers outside, but we are going to take you straight to the ambulance." He informed her, wanting her to know exactly what was going on.

"Ryan. Esposito. We're coming out, we're unarmed, and everything is ok" Castle declared, making sure that they understood there was no threat.

Castle kept on arm around Kate's shoulder as he guided them both out of the bathroom. As they entered the main room of the house he felt her jerk back as she realised how many other people were in the room but she seemed to relax slightly when she realised they were all police. Castle led her out of the building keeping one arm around her, he felt as if he was clutching a skeleton. They made their way over to the ambulance and Castle helped Kate climb inside and lie down on the stretcher. She instantly held her arms close to her chest and pressed her legs together. It was only then Castle noticed the bruising and scars that seemed to cover her legs, wrists and ankles.

A female medic arrived to check Kate over. Castle expected her to freak out but instead she let her take her blood pressure and check her eyes before handing her a glass of water and telling the driver to get to the hospital. Castle watched Kate intently, she didn't say anything but it was clear she wanted to speak, she wanted to ask something, he could tell by the way her gaze was shifting. Whilst the medic was checking her over, tears brimmed in her eyes but she refused to say anything, to call out, she lay there frozen. It was as if she had trained herself to lie still. Once the medic had finished Kate waited a few minutes before finally letting her body relax slightly. Even when they offered her some water she had hesitated before taking it and even when she drank it, it was the smallest sip before she quickly handed it back.

Castle stayed with her in the ambulance, hoping to take some details but it was clear that she wasn't going to be talking any time soon. Any attempts at a conversation were met by more tears in her eyes, he knew she wasn't ready to talk about what she had been through just yet, and it would probably be a while before her mind caught up with everything that had happened to her. So he decided to text and update to Ryan and told him he would meet them both back at the station once he knew more about what was going to happen with Kate, right now he didn't know if she was a witness, a victim or a suspect, so it seemed right that he stayed with her. He told himself it was the right thing to do, even if one of his excuses was that she intrigued him. He knew very little about her, yet he couldn't help thinking about all the things he wanted to know about her. He wanted to know what her story was, what had led her to being in that house and why she looked the way she did. They had managed to wipe away the blood from her face and in a different lighting he could see the tired lines that covered her face, they were much clearer than before, now they were more like clues as to what she had been through.

He watched as she stared up at the ceiling, with only the smallest of glances towards him every few minutes, he couldn't tell if she was just checking he was still there, or if she was making sure that he wasn't going to come any closer to her, he hoped it wasn't the second. He smiled at her, she didn't smile back, but she managed to hold his gaze just that little bit longer each time.

He didn't know who Kate was, or what had happened to her, but he was determined to find out, after all he still had a case to solve and right now it was looking like she was their only witness.

So readers this is my first AU fic. I have the story planned out and most of the chapters are already written so hopefully updates should be every other week. I know that AU stories are not to everyone's liking and this story will be pretty dark in some places, but I want people to remember that this is fiction and is only based on Castle. Also I am not from New York so don't really understand the address system so sorry if it is incorrect.

I hope people enjoy the story, I love to hear what people think so please any constructive criticism is always welcomed. This story is rated T after careful consideration, I do not intend for it to be took graphic as that is not the main focus of the story, however some chapters may be M rated however what is written so far is T.

Updates should be every other weekend, if I keep to my schedule and life doesn't intervene too much.

Anyway enough from me, I hope you enjoy and continue to read this new adventure that Castle and Beckett are about to undertake!

H.