A/N: Okay so i was sat at the laptop reading stories that other people have wrote and i came across one that inspired me to do me to do a crossover between N.C.I.S and CSI.

Pairing: Eventual Tony/OC

Summary: After having a tough break-up with Grissom, Sara Sidel decides to head back Norfolk where she re-joins N.C.I.S after leaving 5 years ago, when her best friend Special Agent Kate Todd died in front of her.

Chapter one:

A young woman in her early thirties approached the building and marvelled at how much it had changed in the last few years. She stood there for a few moments contemplating whether or not to go inside, before walking through the doors and heading towards the main desk. The main desk certainly looked more professional and the staff looked suitable aswell the woman noticed as she waited at the main desk for the receptionist to finish her paperwork. The receptionist was in her twenties and appeared to be stuck up, the woman noticed by the way she walked around with an air of supremity about the place. "May i help you?" she asked stiffly, before taking a quick glance at the clock and sighing.

"I used to work here and decided to pop in for a visit to see a few of my old collegues." the woman said in a polite tone. The receptionist shot her a filthy look that said, well thats what they all say hun before replying,"What's your name then?" in a snobbish tone. The young woman smirked at the receptionist, pleased with the fact that she wasn't dumb enough to fall for the line so simply but also annoyed by the whole snobbish act the young woman was portraying. "Sara-thats without a 'h' by the way-Sidel." she said in a matter of fact tone, watching as the woman typed her name into the database. Glancing back at the woman named 'Sara' the receptionist then asked if she had any proof she was who she said she was. Again Sara smirked as she handed over documentation that varified who she was to the woman and watched as the young woman scowled, when she couldn't find anything bad about her. She reached into one of the drawers and pulled out a VISITOR's badge, putting on the counter with Sara's documents before looking at the computer screen. "Who are you visiting?" she asked in a slightly politer tone. Sara looked around for a moment before leaning over the counter slightly and whispering the names quietly into her ear. The receptionist looked up slightly shocked before typing the names into the computer and pulling out a visitors book for Sara to sign. Placing the pen down, Sara placed her documents back into her bag before placing the VISITOR's badge to her jacket and heading off towards the elevator."Have a nice day." she heard the receptionist mumble as she walked away from the main desk.

The ride in the elevator gave Sara a chance to think about what mistakes she had made in the past and how she would rectify them today. DING! the elevator doors opened and she stepped out onto the floor taking a look around and realized just how many changes N.C.I.S had under gone in the five years that she had been gone. Walking towards the centre booths, the woman felt her breath catch in her throat as she came up to her former best friends station and smiled sadly. I miss you Kate! she thought sadly as she walked around and leaned back against the desk watching a man leaning back on his chair, balancing a pencil on his nose. "Some things never change, eh DiNozzo." she said smirking as she watched the man trying to maintain his balance. When he had finally recovered he looked up to glare at the woman who had caused his very near accident, but that glare soon changed into a look of suprise as he looked at her more closely. "Sara Sidel, well i never would of guessed that it was you stepping into N.C.I.S after all these years." he said in a teasing tone, geting up and walking round to give her a hug. Sara stifled a giggle as she leaned into the embrace before stepping back and slapping him around the head. "Neither did i DiNozzo, but i guess the world works that way for a reason right." she said dismissing his scowl and looking around for the rest of the team. The man noticed this and spoke up, "they should be in soon. So then come back for good or just a visit?" he asked in a casual tone. Sara looked at him and laughed,"please Tony, i just got over having nightmares involving you. I definetly don't need any more." she said in a playful, laughing once more at Tony's mock-hurt look.

The elevator pinged, and Tony looked over Sara's shoulder to see his boss walking over before lookibg back to her to see a questioning glance on her face and he smirked. TWACK! A hand slapped the back of her head and she smiled realizing that her old boss was here. "Ya know i missed you to Gibbs but a simple hug would do. What was the slap for anyway?" she moaned as Gibbs looked at her with his serious face. "That was for taking so long to get your ass back here. DiNozzo isn't there any paperwork that you could do or do you need a slap aswell?" Gibbs said looking between them both. Tony jumped up and practically ran back to his desk whilst an amused Sara walked up to Gibbs."Forgive me Gibbs but what do you mean?" she said in a curious tone but gulped as Gibbs glared at her once more. "Right then,moving on. I need to speak with the director first Gibbs..." but the woman was stopped in her tracks as her former boss held up his hand and shook his head. Seeing the confused expression on her face he went into his draw and pulled out some forms, along with a gun, phone and badge before putting them infront of her. Sara looked at the paper work before glancing at Gibbs with a questioning look on her face. Gibbs sighed. " Sidel you pick up the pen and sign on the dotted line. Jeez, sometimes i think your worse than Tony." he said smirking at her scowl as she signed the papers and Tony looked from his paperwork with confusion. Placing the pen down on the table Sara handed over the paperwork to Gibbs, before picking up her things.

Gibbs stood up and walked around his desk pulling a suprised Sara into a hug and whispering into her hair,"It's good to have you back, we've all missed you."

A/N: This is the first chapter and the reason for Sara leaving CSI will be explained in later chapters. Please read and review and let me know what you think.

Next chapter: Sara is welcomed back by the rest of the team and meets Ziva.