Somebody That I Used To Know

Rating: Teen for now, mature later.

Disclaimer: I don't own CSI or the characters.

Summary: She's just somebody that he used to know.

A/N: So my first serious Grillows fic since I've been back. Hope this is good enough for you guys to stay interested! This is only chapter one! There should be a few more chapters in this little story of mine.

Songs that you might want to listen to while reading: Somebody That I Used To Know - Gotye, Under the Sheets - Ellie Goulding.

It was unusual for the house to be so well lit. As he walked through the kitchen, he notice noticed a few things out of place here and there. Advancing into the living room, he noticed a piece of clothing that looked vaguely familiar. He stopped all together and looked around, then called out her name. She had to be somewhere. His call, not being much louder than his normal conversational voice, seemed to echo in the seemingly empty house. Scanning the living room one more time, he decided to make his way to their bedroom. Upon reaching the slightly parted door, he called out to her one more time before pushing it open and stepping inside the bedroom. More clothes were scattered about the floor, but even with the unfamiliar, bigger pieces of clothing, he couldn't seem to put two and two together.

From the doorway, he could see the steam pouring from beneath the bathroom door. He had made it halfway across the room with his hand on the doorknob when an unfamiliar, deep voice came from the other side of the door.

Gil took a step away from the bathroom, his head tilted to the side in astonishment. Maybe he had heard wrong. His lips parted for a second and it was then that he realized he had no idea what to say or do. Call out to her again? Knock on the door? Walk into the bathroom and confront her? Pretend like it never happened?

And then he heard the mysterious voice again. Much clearer this time.

"Sara, our shift starts soon."

Grissom's jaw, which fell upon hearing the familiar voice, finally tightened. Confrontation wasn't one of Gil's strongest skills. Slowly backing away from the bathroom, he left the room just moments before the door swung open and two towel-clad CSIs stepped into the bedroom that was once Gil and Sara's.

He swiftly maneuvered through the hallway and across the living room, grabbed his keys and cell before walking out of the house and softly closing the door behind him. Once the door was shut, he fell back against the hard wood and let his head fall back. This all seemed unreal. The woman he had devoted a portion of his life to, someone he had trusted, had betrayed him in a way unimaginable. He looked around after pushing himself away from the door.

He couldn't stay here. He couldn't look at her.

Gripping the keys and phone in his hand, he turned to the black SUV that sat in the driveway and began walking for it. After starting the engine and pulling away from the house, he dialed the very familiar number and waited patiently for her soft voice to calm him down.

"Catherine? It's me..."

–

The long drive across Las Vegas had given him ample time to think about what had just happened. Still, it wasn't enough time for him to come to a conclusion. What did he do in a situation like this? His head gave the logical answer, but his heart couldn't.

After pulling into Catherine's driveway and shutting off the engine, he looked down at his cell and saw no new messages or missed calls. He hesitated and dialed Sara's number, staring at the bold, black numbers on his phone's screen. Shaking his head, he quickly erased the numbers and stepped out of the SUV. Before he could even make it to Catherine's doorstep, she had appeared in the doorway with her arms crossed. She attempted to smile, but when she saw the hurt and confused expression he was wearing, the smile faded away and she raised her arms towards him.

"Oh, Gil," she whispered as he walked right into her arms. She was barely tall enough to rest her head on his shoulder. As he hugged her back, his arms snaked around her waist and squeezed softly. She could feel him relax against her body and noticed that his breathing became more even with every second they remained in an embrace. "I'm so sorry," she whispered again, this time, her breath trickling against his skin. She rubbed her hands up and down his back, refusing to let go of him so soon.

They reluctantly pulled apart, but he stayed close and she led him into her house. She closed and locked the door, then turned around to find Gil silently observing her home. He had been there many times, but it looked different now. It was more spacious, open, calming. He turned around eventually, finding Catherine with her arms crossed and leaning against the door she had just closed.

"Are you going to be okay," she asked, her head tilting to the side. He stood, almost awkwardly, in the middle of her living area, closing and opening his hands in a nervous tactic to muster up some confidence in his spoken answer.

"Being it's not anything life threatening, I imagine I'll survive." She pushed herself away from the door and walked up to him.

"Gil, just because it isn't life threatening doesn't mean it didn't hurt," she whispered, placing her hand over his heart, then walking past him and letting her hand slip away from his body. Upon entering the kitchen, she opened the cabinets, grabbing two glasses and advancing for the fridge. He followed her silently, but stayed near the kitchen table and watched her prepare two screwdrivers.

Outside of the kitchen window, he could see the sun partially set and observed all the colors spread across the Las Vegas sky.

"How did you do it," he asked as she handed him a glass full of fresh orange juice and vodka. She was taken back a little at the question, but this was Grissom. If she was going to talk about this, there wasn't anyone else she'd rather share it with. Nodding toward the living room, they both took a place on her soft couch.

"You want to know how I put up with Eddie?" She nodded at her own question and took a long sip from her drink before lowering it to her lap and looking at the man who sat inches away from her. "I had you," she admitted softly. "And Lindsay. You two were what got me through."

"As simple as that?" He hadn't touched his drink, his stomach still a little uneasy. She nodded. He sighed and let his head fall back against her couch. She looked down at her drink and pulled her bottom lip between her teeth, deciding on what she could possibly say to make him feel better.

"Have you talked to her since... you-"

"No," he answered her honestly, reaching forward to set his glass down on the glass coffee table in front of them. "I got home and I didn't think anyone was there," he began the story, well knowing she'd ask how he found out sooner or later. "I called out to her and there was no answer. I walked into the bedroom and that's when I heard them... in the bathroom."

"Who was-"

"Nick," he answered in a low voice, his fingers rubbing the sides of his head in an attempt to tame the migraine that was starting to arise. Catherine's breath caught in her throat when the name came from Gil's lips. There were no words to describe how disappointed she was- in both Sara and Nick. She reached out and let her hand rest on his shoulder, softly squeezing to get his attention.

"Do you want to talk about it?" He shook his head and offered her a small smile. "Well... I image you don't want to go back there. You're more than welcome to stay here. The guest room is already made up." She finished off her drink and offered to take Grissom's, seeing as he hadn't touched it. He apologized and picked up his drink.

She got up from the couch and took a few steps before turning around and looking at him.

"Gil," she called out. He looked up from his drink and at Catherine, who gave him a small smile. "It'll be alright."

"Thanks, Catherine."

–

The night had finally come and after convincing Gil to stay in her guest bedroom, she had left him to watch television in the living room while she showered and got ready for bed. Half an hour later, she had emerged from her bedroom in a pair of shorts and a tank-top. It was getting late and he was still up. She was leaning against the hallway, watching him. Finally, after minutes of watching him stare at the television, she called out to him.

"Gil."

Upon hearing his name, he turned his head and caught her standing in the hallway. She wore a pair of tight, black shorts and a white tank-top that stopped just below her belly button. She took a few steps forward and grabbed the remote, then turned off the television. Darkness surrounded them and she extended her hand to help him off of the couch. Once his eyes adjusted to the darkness, he grabbed her hand and allowed her to pull him up.

"Come to bed," she whispered.

"With you," he asked, the words came from his lips before he could stop himself. It was more of a surprise question than anything, but it didn't stop her from smiling.

"If that's what it will take for you to get some sleep," she answered honestly, leading him back to her bedroom. He stopped her at her doorway and pressed a gentle kiss to her cheek.

"I'll be fine. Thanks for all of this," he whispered before advancing further down the hallway and opening the door to the guest bedroom. He looked back at Catherine, who was watching him to make sure he went in. She smiled and let her hand wrap around the door frame as she leaned out of the doorway.

"You know where I am if you want to talk."

A/N: So this is chapter one. The idea kinda came to me while reading another Grillows fic. I read one where Gil cheated on Sara with Catherine, but I don't think Gil would do that. If anyone cheated in the relationship, sadly, I think it would be Sara. So here's my take on what would happen. Sorry for any grammar mistakes. I have three exams to study for and it's my sister's birthday!