This was originally going to be just a one-shot for a friend of mine but since other people have asked me to write more to do with the Kate Winchester stories, I decided to make it into a full fanfiction story.
It is a story about domestic violence so please don't read if it will offend you or anything, it probably won't ever get too graphic but I don't want to upset anyone!

A/N- Dean 25, Sam 21 and Kate 19. This is set at the beginning of season one. If you've read the other two Kate Winchester stories, it's entirely up to you whether this happened along with those or not :)
Hope you enjoy and please review and let me know what you thought! Thanks for reading!

Sam woke to a loud bang. He sat up in his bed and grabbed his baseball bat before making his way downstairs. He looked into the main room of his house and saw the silhouette of a man crossing the room. He quickly moved from his hiding place to grab the intruder but found himself lying on his back, looking up at the face of his big brother. ''Dean?'' He breathed, his voice a mixture of shock and annoyance. ''Get off me.'' Dean gave him a light smile before getting to his feet and pulling Sam up to face him. ''What the hell are you doing here?''

''I need your help.'' Dean answered him flatly.

Sam scoffed. ''Dean, I'm out. I told you I was leaving that life and-''

''It's Kate.'' Dean cut him off.

Sam looked up at him quickly, annoyance changing to concern. ''What about her?''

''I don't know where she is. I need you to help me find her.'' Despite how much he was trying to cover it, Sam could hear the amount of concern in his brother's usually calm voice. Dean sighed heavily when Sam didn't answer him. ''Sammy please, I'm desperate. And I know you didn't want dragging back into this but I'm literally at the end.. I can't take much more of it.''

Sam nodded, knowing that he must literally have been at a last resort when he showed up on his doorstep. ''Okay.'' He said calmly. ''Just tell me what happened. When was the last time you saw her?''

''Almost two months ago.. We got into this fight. I said some stuff to her that I shouldn't have said and.. She left.''

''I take it you didn't find her.'' Sam muttered.

Dean shook his head. ''I looked everywhere for her. Found all her stuff in a motel, her phones, ID's-''

''Anything that she could have on her that would help you to find her.'' Sam finished.

''Yeah, she doesn't want me to find her Sam.''

Sam looked at him carefully. He could tell he was hiding something. ''You're not telling me everything are you? How do you expect me to be able to help you if you don't tell me what's happened Dean?''

Dean sighed and looked down for a second before looking back to his brother. ''The fight we had, it was over a guy. She'd been seeing him and..'' He shook his head. ''Trust me, he wasn't a good guy. And I said to her, if you wanna stay with him fine, I'm having nothing to do with either of you. When I got back they were both gone.''

''And that was the last time you spoke to her?''

He shook his head. ''She called me the day after and told me that she was staying with him and that she quit. Haven't heard from her since.''

Sam thought about it for a minute, trying to work out how the sixteen year old he'd left could have turned into someone who would do that. ''We'll find her Dean.'' Sam said, trying to sound reassuring to his brother.

''It won't be that easy Sam.''

''I don't care. We're not stopping 'til we find her.''

''Yeah, I hear ya.'' He said glumly.

''Hold on..'' Something suddenly dawned on Sam. ''Where's dad?''

''I dunno, I haven't heard from him in a few weeks actually.'' He said slowly. ''It was just Kate and me, dad was taking care of something else.. Then she went MIA, I called him but he didn't pick up. I didn't really have time to worry about where he was.''

''Right.'' He said quietly. ''Let me grab some stuff and we'll hit the road.'' He smiled as he turned away from Dean, heading out of the room.

''Sam wait.'' Dean called after him. ''I know you don't want this life.. You don't have to come.''

Sam shrugged. ''She's my sister Dean. I'm not sitting it out.''

The two of them arrived at Dean's motel room a few hours later. Dean pushed open the door and threw his car keys to the table. Sam took a seat as Dean handed him a bunch of papers. ''This is everything I know about him.''

He picked up a couple of the pieces of paper and raised an eyebrow. ''You mean you didn't try looking for him online?''

''You're the nerd in the family Sam. Not me. I wouldn't even know where to start.''

Sam laughed lightly. ''Sure, give me a few hours. I'll see what I can find.''

Four hours and eight coffees later, he found what he was looking for. ''I don't believe it.'' He muttered to himself. ''Hey Dean.'' When he got to answer, he looked over at his brother who was passed out on one of the beds. Sam walked over and sighed. He could see that his brother was exhausted and he was pretty sure he hadn't gotten a good nights sleep since Kate had left. ''Dean.'' He said again, slightly louder. When he still didn't respond, Sam decided he was leaving him to sleep. He picked up his jacket and made his way to the door.

He pulled up outside an apartment building and got out of the car, walking quickly towards the door. He ran up the stairs to the third floor and walked down the hallway, coming to a stop outside one of the doors. He took a breath and knocked.

He waited a couple of minutes before the door opened a little, Kate looking warily through the small gap. Her face drained of colour as she realised it was him. ''Don't even think about closing this door Kate.'' He said in a hard voice. She glanced over her shoulder for a second before looking back to him. He watched as she thought it over, sighing and taking a step backwards, turning to walk away from the door. He pushed open the door and followed her into the small room, closing it behind himself as he entered.

He stared at her for a minute as she turned to face him. It had been almost three years since he'd seen her, he had no idea what to say. When he didn't say anything to her she folded her arms across her chest and pulled her baggy shirt tighter around herself. ''What do you want Sam?'' She asked, still refusing to look at him.

''What do you mean, what do I want? You bailed, Dean's spent weeks looking for you.. He thought you were dead.. And you're asking me what I want?'' He shook his head and looked away from her.

''I bailed? Is that what you just said to me?'' She asked him quietly, standing up straighter. ''From Dean I can take that, but you? Sam you bailed a long time ago.''

''I know I did. And I'm sorry but- '' His eyes to fell to some bruises above her wrist, clearly left there by someone's hand. ''What's that?'' He asked her accusingly.

She looked down and pulled her sleeve down to cover it. ''Nothing.'' She muttered flatly. Sam took a step forwards and grabbed her arm, pulling it towards him and shoving up her sleeve to show several cuts and bruises on her arm. ''It's from a hunt.'' She said defensively.

His eyes moved to her face, the pain clearly written over it. ''What are you letting him do to you?'' He whispered.

She pulled her arm away from him harshly. ''Leave it.''

''Kate please..'' He pleaded with her. ''Please.. Tell me what's going on. You'd never let someone push you around like he's doing..''

She looked into his face, tears glistening in her green eyes. He could tell she wanted to tell him everything that was going on but something was stopping her. ''You don't know me Sam.'' She whispered. ''You haven't for a long time.. You need to go.''

''I'm not leaving.''

''Sam please, you need to go.. Before he comes back.'' That's when he heard it. In those four little words that he was pretty sure she hadn't meant to say.

''What did you say?'' He asked quietly.

She shook her head and sighed as she pushed him through the doorway, throwing him an apologetic look before slamming the door in his face. Sam stood looking at the door for a couple of minutes, trying to get his thoughts together. He turned and began walking slowly back to the car to take the long drive back to the motel, working through how he was going to explain to his brother what he had seen there.