Something was going on in the world of Donald Flack, Jr. Danny couldn't pinpoint what it was exactly, but something was weird with his friend – and the fuzz surrounding the whole thing was driving him crazy.

Over the years of working as a CSI, he had seen the various detectives assigned to the different cases walk in and out of the numerous labs, but only for a little while. They would find the person who they needed to talk to, would engage them in the obligatory conversation, and then leave. To all appearances (and in this case they weren't deceiving), the detectives would prefer to never have to enter the CSI labs for any reason if they could.

Yet Detective Flack seemed to spend most of his free time there.

Of course he had been there a lot before the "difference" (as Danny had taken to calling it in his head). He had many friends there, and would often stop mid-day to see if any of the CSIs were free for lunch (which they usually weren't). Many times he would walk by the break room to find Flack entertaining Stella or Aiden with one of his many tales of crazy perps over a quick cup of coffee. But now, the amount of time the detective's smiling face was seen around the halls of the crime lab was about to rival his own.

Danny had taken to watching the older man whenever he was around him ever since he had realized something was off. At first he had thought that it might have been the haircut. But as time passed and he grew used to the shorter 'do, something still felt different.

If he had to guess, he would have said that it had started after Aiden had left, though he really be one hundred percent sure of his perceived timeline. Although, and he might have imagined the whole thing, right after the brunette had been fired, there had been a short period of time in which Flack steered clear of some of the labs as much as he could.

Danny shook his head as he turned his attention back to his paperwork with a sigh. Maybe he was wrong about his friend. How much did he really know about the situation, if you could call the whole thing a situation, anyways? All he did know for certain was that Flack was finding more and more excuses to stick around the crime lab, even if that meant offering his assistance to Mac doing various tasks that any intern could have done.

Sighing again, he removed his glasses and rubbed his tired eyes. This was going to bug him until he figured it out. Which he would. He wasn't a CSI for nothing.

"This isn't going to work if you keep moving!"

"Well, I'm sorry."

Danny backtracked a few steps to the reconstruction lab he had just passed as two very familiar voices caught his attention. As he peered into the large room, he saw Lindsay's back as she looked like she was talking to . . . a wall? A talking wall?

Entirely confused, he walked into the room. "What are you doin', Montana?"

Her head turned to grace him with a look of frustration. "What does it look like, Messer? I'm trying to recreate the crime scene." She took a step back and Danny had to hold back a laugh at the sight before him.

Flack was flat against the wall, his arms spread apart and slightly above his head as they were tied to the wall behind him with rope. His hands were covered with the requisite latex gloves and he had stripped down to a white tank top.

"How ya hangin' in there, buddy?" Danny teased him.

"Bite me, Messer."

Lindsay tried to speak over Danny's laughter. "We're trying to recreate the circumstances of the victim's death, Danny," she explained, stressing his name to get him to be quiet. "Mac had to run to court, so Flack here volunteered to help." She turned to look at the detective in question and he flashed her a big smile, a gesture that Danny did not miss.

Seemingly innocuous details from the past few months were rapidly falling into place, as if the puzzle pieces were falling into position on their own. He was still missing a few bits from the whole picture though . . .

He cleared his throat and tried to clear his head. "So how exactly does treating Donny here" (Flack glared at the use of the special nickname) "like some sort of sex slave help with your case?" A wave of emotion washed over him, and he couldn't quite figure out what that emotion was.

As she moved over to the table a few feet away, she began to enlighten Danny on the procedure. "We think the second victim was tied up in the same fashion as Don is right now." She grabbed a bucket of what appeared to be red paint and a knife out of the rows of tools lying on the table and moved to stand in front of Flack. "We need to match the cast off pattern from the first victim to a specific weapon and position." She turned slightly to the other CSI. "Would you mind working the camera?" she asked sweetly and granted him a smile.

Whatever it was that caused him to fall prey to that innocent grin, he may never know. But Danny did as she asked and reached for the camera on the corner of the table and snapped off a few 'before' pictures. He hadn't missed the use of Flack's first name that seemed entirely too personal for someone who had only been at the lab for a matter of months. Another puzzle piece fell into place as he moved around Lindsay to the other side to take a few more pictures.

"Okay," Lindsay began and looked down at her feet as she took a deep breath. She glanced up at Flack and caught his eye. He sent her a reassuring look with a smile. "Let's get started."

The entire process took about forty-five minutes to complete. Mac and Lindsay had narrowed down the possible weapon to four choices beforehand, but the reconstruction had involved a number of steps that had to be done very carefully.

First, she would dip the edge of the tool into the red paint and would move it in an arc as if it was being used as the murder weapon. The paint would move off of the blade to create a cast-off pattern on Flack's white shirt, which Danny would then photograph a couple of times from different angles.

They would then untie him and have him (very slowly) remove the shirt and put on another, identical tank top. And while Flack seemed to have no qualms about being shirtless in front of Lindsay, Danny was growing very uncomfortable about the whole idea as the fuzz started to fade.

As Lindsay laid the last shirt across one of the tables, Danny snuck a glance at her face. If he wasn't mistaken (it had happened before), a grin was threatening to break free across her features. Out of the corner of his eye, he could see Flack approaching them as he pulled on his shirt and buttoned it up.

"Hey Lindsay," Flack called to her. She turned around quickly and smiled. "Can I talk to you for a minute?"

"Sure," she agreed and began to move over to the doorway where he stood, turning back a second later. "Danny?"

He looked up. "Yeah?" Oh, that didn't sound eager at all. What's wrong with you, Messer?

"Can you finish up with the pictures for me? I'll clean up once you're done." There was that smile again.

Danny nodded his agreement and moved as if to look through the camera when all he was really doing was watching the couple while pretending to be working. He tried telling himself that he was being stupid. Really, was it really worth it to get all worked up over it . . . whatever it was? But he just told himself to be quiet, because she was starting to speak.

"Something wrong?"

"No, nothing's wrong. I just want to apologize for moving so much while you were . . . working."

She shrugged. "It wasn't a bother. Don't worry about it."

"No, but I want to make it up to you. And I know just how I can do that."

"How?"

He really didn't like that look on Flack's face. In fact, he had only seen that look once before, when they had gotten hammered at a bar after a really tough case and Flack had tried hitting on this girl who . . . no. No way. No way in fucking he-

"You wanna grab a bite to eat after shift today? Maybe catch a movie?"

An enthusiastic smile spread slowly across her face. "Sure. I'd love that."

His face mirrored hers as he lightly grabbed her hand and added, "I love that you'd love that."

A light blush was coloring her face as they stood silently for a moment looking at each other, while her hand still rested in his. Danny cleared his throat. Loudly.

They broke apart and Flack headed for the door. "I'll see you later then, Linds." He walked out and headed towards the elevator, throwing a 'see ya later, Messer' over his shoulder.

From the self-contented way he was walking, Danny thought that the detective should have been whistling. How had he missed that? All the extra time Flack had been spending in the lab was to be near Lindsay? The timing made sense now, seeing as how it had started after Aiden was gone. When Montana had taken her place . . .

That's all he had seen her as at first, as a replacement for one of his best friends. And evidently his other best friend didn't feel the same way about the newest CSI. What was he going to do about this? And why did he feel he needed to do anything about it at all?

"Danny, what time is it?"

"Where's your watch, Montana?"

"In my locker."

"Now how does it do you any good all the way in there?"

"I took it off to do the procedure earlier. Now can you just tell me what time it is already?"

"It's past six," Flack answered her as he strode into the trace lab where they were working. He was already wearing his heavier coat and gloves and looking like a kid on Christmas morning. "Shift's over. You ready to go?"

Lindsay glanced at Danny over at the microscope. "You need anything from me before I go? This case isn't getting any breaks at the moment."

Danny seriously considered telling her that he needed her help and that she couldn't go just yet. But what would that accomplish? And what could he possibly draw together in a few minutes to have her assist him with? At least he knew when he was beat. Not trusting his voice, he shook his head and quickly turned his focus back onto the evidence in front of him.

Not that he didn't notice the way Flack's eyes trailed up and down Lindsay's body as she stretched and pulled off her lab coat. And not that he didn't notice how Flack offered his arm to Lindsay as she walked to the door. And not that he didn't see the way Lindsay's face glowed as she gladly took the proffered arm as they headed towards the locker room.

He was really beat.

"I can't believe that's what people think cops are like!"

"You can't believe it? I'm the one with a family full of cops! These movie people should come to me if they want to know what real cops are really like."

Lindsay giggled as she moved closer to Flack. It was snowing, and he had decided to walk her back to her place rather than calling a cab. They were almost there, just a few buildings down, but already she was beginning to feel the effects of the cold. As if he was reading her mind, he wrapped his arm around her smaller frame and pulled her closer.

"What? You don't believe me?" Flack purposely tried to make his voice sound hurt, but only succeeded in making her laugh harder. "I'll have you know that I am an expert on the NYPD."

"That I can believe," she told him as they stopped in front of her building. "It's just that . . ."

"Just that . . . what?" he asked her as she trailed off.

Lindsay lifted her head to look directly into his eyes. "I doubt that all cops have eyes like yours, or spend as much time on their hair as you do." She reached up to ruffle his hair but he caught her hand and pulled it against his chest as he wrapped his arms around her waist and pulled her nearer.

"I'll have you know, sweetheart, that I spend less time on my hair than Danny does on his." He leaned his head down. When his lips were a few inches from hers, he asked, "And you know what?"

"What?" she replied in kind, her breath warm on his lips.

"I doubt that all CSIs in Montana are as gorgeous and intelligent as you."

And with that, he swiftly closed the gap between them and pressed his lips softly to hers. As he felt her responding, he deepened the kiss, lightly licking her lips until she opened her mouth.

The kiss grew more passionate as their tongues battled and their mouths meshed together. After a few minutes, Flack reluctantly pulled back. He rested his forehead against hers and took a deep breath.

"You have no idea how long I've wanted to do that," he breathed out, his words seemingly floating with the vapor on the cold air in front of him. He leaned back in for a light peck.

"I have a good idea," she said as she closed the space once more before grudgingly pulling out of his embrace and walking towards her door. "I'll see you tomorrow, Don."

"Yeah. Bye Linds." Flack stood and watched her until she disappeared from sight up the stairs, then waited until he saw a light turn on until he walked off down the street.

And this time he did whistle.

TBC