"Kirsty." Sara held her hands up defensively, instinctively rising from the couch to put more distance between them. "That was a long time ago – before she and I were even on the same team."

"Oh, I know that." Kirsty chewed on the inside of her cheek, cocking her head to the side in mock-curiosity. "What I don't get is why you didn't tell me."

Sara swallowed again, stumbling over her words.

"I didn't think it was important." She squeaked at last. "It was barely even a relationship."

"Well, she seemed to think it was."

"What did she say?" Sara asked softly. She was genuinely puzzled as to why her ex had felt the need to mention it at all. It's not like they were even friends anymore; and lord knows Sofia was more than happy to keep quiet about things two years ago.

In fact, she was even more determined about that than Sara herself was.

"Oh don't worry." Kirsty scoffed. "She told me all about your little trysts."

"Trysts?" Sara repeated, shaking her head in bemusement. That did not sound like something Sofia would have said.

"Is that why you're always 'working late'?" The other woman pressed coldly, finally pushing herself off the couch and taking a step towards her increasingly anxious girlfriend. "So you can hook-up with your ex?"

"Of course not!" Sara stiffened at the accusation. "I would never …" she paused, clamping down on her indignation. "Look, Sofia and I are colleagues. Nothing more."

"Yeah, sure you are." Kirsty flicked her long, untameable hair over her shoulder sullenly.

"Kirsty, I have never cheated on you." Sara insisted through gritted teeth. "I never would."

Kirsty lifted her gaze slowly to seek out Sara's.

"Really? So why you were going to break up with me?" She asked in an eerily calm voice.

Sara stuttered, caught off guard.

"Well, that is what you wanted to talk about, isn't it?" She guessed, correctly as it happened.

Unable to form coherent sentences, all Sara could do was look away; an answer that spoke a thousand words.

"I'm sorry." She mumbled at last. "I just don't think it's working out. And it's nothing to do with Sofia, I promise … it's just me."

Okay, it wasn't her, but now was hardly the time to start throwing stones.

To her surprise, Kirsty laughed. But it was a cruel, heartless laugh that left Sara's blood cold.

"Oh, it's you alright." She agreed bitterly. "You're just lucky that I'm willing to forgive and forget. For now."

Sara's brow furrowed in confusion.

"What do you mean?"

"I mean," Kirsty took a step closer and Sara responded with a deliberate step back, until she felt the kitchen counter against her spine. "Miss Sidle, that you are not breaking up with me." She paused, her lips turning into a callous sneer. "Not unless you want your boss to find out about you and Sofia, that is…"

Sara's eyes widened, the knot in her stomach tightening with every passing second.

"You wouldn't…" she mumbled, her voice betraying the gut-wrenching fear she was feeling right now.

"Why don't you try me?" Kirsty challenged with a smirk. "Maybe while I'm at it I can tell him all about your family history, too. I bet they'd love to hear that story."

Sara's face fell, every ounce of colour draining from it until her skin was a deathly shade of white.

She didn't know what scared her more right now:

The thought of what her team might say if they found out about her sordid past;

Or the realisation that she hadn't even told Kirsty about that part of her life.

X x x

"Hey," Catherine was on her feet as soon as Sara entered the locker room and it was obvious from her anxious twitching that she had been waiting for the brunette to arrive. "So, how'd it go?"

"Fine." Sara cleared her throat, stepping around her supervisor and pretending to busy herself in her locker.

"So, she took it okay?" Cath frowned, following her across the locker room to lean against the metal doors. "Nothing happened?"

"Nope."

"Huh." She hummed. "Well, that's good."

"Yeah." Sara turned, a half-sarcastic smile on her lips as she attempted to vacate the small room before any more awkward questions could be sent her way. She had actually planned on tidying her locker out - that was partly why she was so early - but it could wait until she was alone.

Catherine frowned at her departing colleague; something about her demeanour was off.

"You didn't do it, did you?" She asked before Sara could escape. The younger woman stopped in the threshold. Her shoulders visibly slumped and she dropped her gaze to the floor in shame.

"No, I didn't." She agreed at last.

Slowly, Catherine stepped towards her and reached out a hand to brush her arm.

"What happened?" Her voice was non-accusatory, but Sara could tell she was disappointed. She turned around, tears shining in her eyes.

"I'm sorry." She shook her head helplessly. "I couldn't do it."

X x x

Having re-located to a more private location and palmed the boys off with a feeble excuse for missing the start-of-shift assignments handout, Catherine hip-checked her office door closed and handed Sara one mug of freshly brewed coffee.

Sara accepted it gratefully, nursing it between her hands as she sank back into the sofa cushions.

Without a word Catherine locked the door, shut the blinds and joined her on the couch.

For a long few minutes, neither of them spoke or made eye contact as they sipped their drinks. At least, Catherine sipped hers; while Sara prefered to stare into it forlornly, as if it held the answers to all of her problems.

"The Bellagio." She stated randomly at last, breaking the heavy silence between them. However, though grateful for the conversation starter, Cath didn't understand the reference.

"That's when I decided I was going to end it." She explained upon noting her colleague's confused frown. "She'd booked us a meal and a room – 7pm sharp. She went to so much trouble to get everything right … and all I could think about was how I could keep her from touching me."

"Honey," Cath reached out to brush the back of her hand gently, but Sara pulled away from the movement. Realising that the cagey woman was not in the right frame of mind for physical contact right now, Cath grudgingly retracted her hand.

"I just can't trust her anymore." Sara mumbled sadly, staring into the dark liquid with intense concentration.

"Then why didn't you end it?"

It was a perfectly logical question, but Sara didn't have an answer. At least, not one that she could share.

"I couldn't." Was all that she could offer, pitiful as it was. "I want to, but I can't."

"Sweetheart," Catherine shifted, rubbing her forehead in deliberation. "I know how scary it is to leave someone who's hurting you; I know that you feel guilty, like you owe them another chance. But you don't. And as long as you stay with them, they'll just keep on hurting you."

"I know that." Sara murmured, looking away.

"But it's okay sweetie." Cath continued earnestly. "Once you do this, I promise we can protect you. She won't be able to hurt you anymore."

"Cat…" Sara attempted to interrupt, but the blonde wouldn't let her.

"Sar, whatever it is that you're scared she's going to do to you, I promise I won't let it happen."

"No, it's not that." Sara finally managed to say, shaking her head firmly.

"Then what is it?" Catherine pressed, daring to reach out and rest a hand on her knee and; though Sara didn't pull away this time, she didn't answer the question either. Her evasiveness prompted Cath to move closer on the couch, effectively pinning the younger woman in the corner. "Sara, whatever it is that you're scared of, you can't let it hold you back. Please honey, you have to end it before it gets out of hand. Please."

Catherine Willows was not by any standards a woman who begged. But she was willing to make an exception in this instance.

However, her desperate pleas fell on deaf ears as Sara shook her head determinedly. When the young CSI finally lifted her gaze, unshed tears were glistening in her wide, hazel eyes.

"No, you don't understand." She whispered, the words catching in her throat. "I can't."

X x x

Having left Catherine sincerely confused, Sara decided that she needed to go for a walk somewhere to clear her head.

Unfortunately, Las Vegas was not San Francisco and there were few scenic areas suitable for leisurely strolls in this area of the town.

Which is how she came to be on the roof of CSI instead.

Despite being a fair distance away from Downtown and the Strip, you still got a pretty good view of the city from up there. The garish lights masked any stars that were above them, but on a clear night you could just about see the moon shining down on the desert

Usually this side of the roof was sheltered from the wind, but tonight there was a distinctly cold breeze blowing around her. She, however, barely noticed.

She was too numb to feel a thing anymore.

Behind her, the heavy steel door creaked open. She cast a brief glance over her shoulder, expecting to see Catherine hovering behind her with the usual look of concern on her face.

To her surprise, it was Greg who had found her hiding place.

Catching her eye, he smiled and ambled over casually to join her against the railings.

"Nice night." He hummed approvingly.

"Yeah." She breathed half-heartedly. She supposed it was, although she had been too distracted to notice.

He scrutinised her closely from behind his lashes, contemplating how he was going to address the issue on his mind. Unfortunately for the ex-lab rat, she beat him to the punch.

"You know, when I first came to Vegas I hated it here." She admitted quietly. "I hated the lights, the fact that it never really gets dark here. I hated the noise from the casinos; the tourists. The desert heat." She paused, licking her lips. "But now, I can't imagine myself living anywhere else. And it's not because of the city, or the job. It's the people. I've never really felt truly safe around anyone the way I do around you guys."

Greg blinked at her in surprise, not entirely sure how to handle her odd confession. It was so rare to get even a glimpse of Sara's psyche that to see her like this, her soul completely bared, felt like he was somehow intruding on something he wasn't meant to hear. The last thing he wanted to do was ruin the touching moment by scaring her back into defensive mode.

On the other hand, the fact that she was opening up meant something must be very wrong.

Without wanting to startle her, he slid his hand along the railing until it brushed against hers. She jumped at the contact and her movement allowed him a brief glimpse of the tear tracks reflecting on her pale cheeks. She didn't even seem aware of them herself as she blinked at him in surprise - as if she'd forgotten he was beside her.

"What's wrong Sara?" He asked at last, his usually playful voice hoarse and thick with worry.

Without speaking, she stepped closer to the young man and allowed him to wrap an arm around her waist from behind. She tipped her head back against his shoulder, letting him support her weight as she relaxed for just a moment.

"Greg." She mumbled at last. "If I tell you something, will you promise not to judge me?"

"Of course." He frowned, tightening his grip around her middle.

However, he never got a chance to prove it.

As she opened her mouth to speak, an instantly recognisable alarm shattered the peaceful silence and below them people began piling out of the building into the cool night air.