Disclaimer: I don't not own anything related to CSI. If I did, we might actually have seen what happened when Grissom and Sara finally got together!

Spoilers: Season 4. Butterflied, mostly.

This is my take on what could have happened after Grissom's little speech in the interrogation room to Dr. Lurie.

Please enjoy! And review…

'It's over', she thought, as she stared through the glass partition at the man with the bowed head.

He hadn't moved since the officer had ushered the suspect out into the corridor. She couldn't see his eyes and she certainly didn't know what he was thinking. His face gave nothing away.

She was grateful that she was alone in the observation room, and that if happened to look her way he would only see a mirror. She was positive that her feelings were written plainly on her face.

"I couldn't do it."

Suddenly, she had to get out. She was conscious of an overwhelming feeling of claustrophobia, and her only clear thought was that he should never know. She couldn't let him know that she had overheard him. Throwing one last glance at her boss, she pulled open the door and hurried out. She felt trapped, and she needed to get some fresh air.

Just as she reached the doors that let to the parking lot, she heard Nick call her name. She turned and watched as he came towards her.

"Have you seen Grissom?" he asked.

She wanted to laugh wildly. What a question. Had she seem Grissom? Of course she had seem him! She had heard him pouring his heart out to a murderer, telling him things that he should have said to her long ago…

But she didn't say any of those things. She wouldn't give a voice to any of those thoughts that were whirling around her brain and making it impossible for her to think rationally.

Instead, she pretended to think about his question, and eventually replied: "Yeah, a while ago. I think he said that he was going to interrogate a suspect."

She had spoken calmly, but Nick's eyes went over her deathly pale face and her unusually bright eyes. "Are you ok, Sara?…you look sort of…"

She forced herself to laugh, and cut across him. "I'm fine, Nick. I'm just a little tired, that's all."

He could well believe it, but he looked at her somewhat doubtfully. Then his eye was caught by the appearance of someone else on the corridor.

"Oh. There's Grissom." he called after his boss, "Hey, Griss!"

Sara smiled at Nick and swiftly made her escape.

Grissom regarded the brunette's retreating back. He hadn't spoken to her in days; he just couldn't have. The case had been too important to him, and he couldn't have dealt with seeing her. Still, it was strange that she was leaving now. Although the shift had ended, Sara normally stayed late to finish off cases or to look over cold cases. Maybe…

But his train of thought was interrupted when Nick began to ask him for advice on a case. He rubbed his face tiredly and prepared himself to give an opinion.

Out in the lot, Sara sat on the hood of her car with her legs crossed like a Native American. She had her cell phone in one hand and was absentmindedly rubbing it up and down her thigh. She was staring at the pavement without really seeing it, replaying his words over and over in her mind…

"I couldn't do it."

What did he mean? What did he mean? But in her heart, she knew the answer: it meant the end.

She had known him for ten years, worked with him for four, been in love with him for God knows how long, but now it was all over. There was only one thing left to do. She had wasted four years of her life and she wasn't going to waste any more. She took a deep breath and started to dial…

She was still sitting on the hood of her Tahoe twenty minutes later, when Grissom came out. She didn't notice him at first, but when he called her name she jumped up as if she had been stung.

She looked rather embarrassed, but before she could speak, he said: "I'm sorry. I didn't mean to scare you. Are you ok?"

She blinked. 'I must look like crap,' she thought, 'he only ever asks me how I am when I look terrible.'

But she smiled and replied quietly: "I'm fine."

They stood looking at each other for a moment and, for once, Sara's over-talking didn't kick-in. Now that she had made her decision, she didn't feel inclined to rush in and break the silence. Eventually he spoke again:

"I'd thought you'd left."

"No, no. I was just taking a break. I hope that you're going home though. I know that you haven't had much sleep the past few days."

He looked surprised, but for once she didn't blush at the realisation that she had basically told him that she had been checking up on him. She felt tired and sad, but calm as well. It was as if nothing could touch her anymore.

"Yes, I'm just on my way out."

"So you're finished with the case, then?" she knew he was, but she just wanted to see what he'd say.

He inclined his head in answer to her question. It was clear that he didn't feel like talking.

"He's guilty as sin." she commented, "Why did he do it?"

His eyes snapped to hers sharply, but her face gave nothing away. "It's all in my report, Sara. Goodnight."

He turned away from her and thought he heard a little sigh before she said "Goodnight."

Sara Sidle watched him thoughtfully as he approached his car. She was so wrapped up in her thoughts that she almost jumped out of her skin when her cell phone rang. She answered it quickly: "Sidle."

She listened for a moment before replying: "Thank you for getting back to me at such short notice…." "Yes, I'm available whenever you need me."

She was suddenly horribly aware that Grissom had paused in the act of getting into his car and was now listening. 'I can't let him hear this', she thought.

"Can I call you later and we can sort out the details?"

"Great, I'll talk to you then. Goodbye."

Without turning around to look at her boss, she shut her cell phone and called out: "'Night, Grissom." before heading into the lab.

'How did she know I was listening?' he wondered, as he climbed into his car and drove away.

Inside the lab, Sara watched his car pull out. 'That's the last time I'll ever see him.'

But she had no time for such musings and she quickly got to work.

She cleared her locker into her sports bag and locked it shut. The she swiftly mad her way to her boss' office. It was still open because Catherine had told her the she needed some files and would lock up later. She pushed open the door and pulled out an envelope from her pocket. She laid it on his desk- the black typed letters staring up at her: Dr. Gil Grissom.

She'd been carrying it around with her for a while, too scared to give it to him, always hoping that if she stuck around he's show her that he did feel something for her. Tonight she had discovered that she was wrong. The placed her ID tag, her locker key, her pager and her lad-issue cell phone beside the letter. Then she exited the office and carefully shut the door.

Grissom had the next shift off and hopefully he wouldn't get her letter of resignation for 48 hours. That would give her plenty of time to clear out her apartment (she'd never really unpacked) and get on a plane to San Francisco.

Yes, with any luck she wouldn't have to see him again.

She couldn't say goodbye to anyone, because she knew that they'd call Grissom. So she said goodnight to Warrick, Catherine and Greg, and surprised Nick by giving him a quick kiss on the cheek. He looked at her in surprise.

"Rough day," she explained, "Goodnight." And she quickly left the layout room.

In the lot she paused and turned to say a silent goodbye to the lab that been her home for the last four years. But she didn't look back as her Tahoe pulled out and headed home.

AN: what do you think? Any good? Please review- it's my first CSI fanfic and I'd love to know how I did! I have another part- should I post it??