She rolled over and glanced at the clock, careful not to disturb her lover who was sleeping soundly next to her. It read 15:00 and Catherine was still wide awake. She was very thankful that although Sara didn't sleep much, when she did she slept like a log. She couldn't bear the idea of having to lie to the woman she loved about what was bothering her, so she tried not to let it show.

Despite spending every moment since yesterday trying to find a way out of her problem, Catherine could think of nothing else she could do except go and dance for Mark.. If she didn't, Eddie would tell Grissom and he would have no choice but to transfer one of them to another lab, which would be in another city. How could they maintain a relationship like that? The only other option once Grissom found out would be for one of them to quit. Sara, with her unselfish nature, would argue it should be her, and Catherine wouldn't let her do that. It would undoubtedly cause tension between them if one of them had to sacrifice a job they loved on the altar of their relationship.

No, she thought, Grissom mustn't know. And aside from killing Eddie, which was looking more and more tempting right now, the only way to keep it from him was to do as Mark asked. She wondered what Eddie was getting out of this. Maybe Mark was paying him, maybe it was brotherly love, hell, maybe he just enjoyed making her suffer and trying to break up the best relationship she had ever been in. Knowing Eddie, it could have been elements of all three.

She knew it would have to be a secret from Sara. She couldn't stand the thought of her possessive lover knowing that half of Las Vegas would be seeing her practically naked. She didn't know how Sara would take that. Catherine was an honest person by nature and it hurt her so much to think she was going to have to lie to someone she loved, but it may well be the only way to save their relationship, she realised.

She carefully leaned over Sara's sleeping form and picked up her mobile phone from the bedside table. With growing feelings of guilt and dread, she started to text Eddie her answer.

* * * * * * * * * * * * * * * * * *

Sara's tongue slipped past Catherine's lips and ran over her teeth before duelling with her tongue. Sara's hands wandered over Catherine's back then slid round her hips, over her stomach and up to undo her buttons. Up till then, Catherine had been responding, her hands tangled in Sara's dark hair, but now she pulled away.

"Stop."

Astonished, Sara released her hold and stepped back. "What's wrong?"

"I just.I'm not in the mood, Sara."

"But." Sara shook herself. She must have read the signals wrongly. Again. "Never mind. It's okay. Come and sit down, we'll watch some TV."

Catherine felt tears brimming in her eyes and fled the room, whispering, "I'm sorry," as she went. She practically ran, trying to get to the cool air outside to calm down. Sara caught up with her at the front door, and led her back into the living room.

"What's wrong?" She sat them both down on the settee.

"Nothing. I'm fine. Sorry, I just haven't been sleeping properly recently and I'm tired." She managed a wan smile, and kept the guilt and pain she felt at lying buried as much as she could in case Sara saw it.

Sara, not totally satisfied but unable to pinpoint why, just nodded. "Catherine, can I ask you something?"

Catherine nodded, half terrified in case Sara had found out yet half hoping she had.

"Do you still find me attractive?"

Surprised, Catherine hurried to reassure, "Of course! What on Earth makes you ask that?"

"You never initiate sex with me anymore. And when I do, the whole time it's like you're not really there. Like you're putting up this wall between us. And then tonight, you turn me down. Cath, that's never happened before in the ten months we've been together. If you were anybody else, I wouldn't be so worried, but it's always been me who couldn't keep up with you." She finished with an apologetic smile, trying not to sound accusatory.

Catherine couldn't think of how to reply. It was all true, but there was no way she could explain to Sara that she felt like a fraud being intimate with her. That she was scared the closeness one night might make her confess everything, or that Sara would take one look into her eyes which were always so expressive post-orgasm and know the truth. Then she would lose her forever.

"Sara, I love you with all my heart. I've just been so busy recently with everything that's been going on at work and with Jane being in hospital. I'm worried about her, she's one of my oldest friends." She felt a heaviness in her heart at making up such a sickening untruth. But she had needed a reason to tell Sara for why she was out so often. Visiting a sick friend gave her an excuse to be out of the house for a few hours each weekend. She felt even worse because it was tantamount to emotional blackmail; trying to get Sara off the subject by making her feel compassionate.

It worked. "I'm sorry, of course you are." Sara ran her fingers through her hair. "I didn't mean to imply you shouldn't be worried, or that you shouldn't go and see her. Just forget I said anything."

* * * * * * * * * * * * * * * * * * *