"Are you always this selfless?" Grissom asked an hour later as he and Sara gathered their supplies in preparation for another burglary. "Have you sent yourself on any interesting cases yet, at all?"

"Yes," she said. "I'll have you know that I took a murder the week before you came."

"It's been almost three weeks since you worked a case that actually required thought? Has your brain atrophied yet?"

"You tell me – you've been listening to me try to communicate all day."

Grissom looked thoughtful. "Well, it seems to be in relatively good working order. But really, Sara, if you don't challenge yourself then you'll end up hurting both yourself and your team, rather than helping them like you think you're doing."

"Yeah," Sara said, looking skeptical, "but I have plenty of experience with serious crime. I don't need to spend time concentrating on it. These guys, on the other hand, have probably been lucky if they've seen one murder each in their careers. I have to get them prepared to do this for themselves, or else when I . . ." Her words abruptly cut off. "They just need to know how to do things," she told him flatly.

" 'When you ' what, Sara?"

"Nothing. Slip of the tongue," she said dismissively, and grabbed another jar of fingerprint power to toss into her kit.

Grissom was unconvinced, but he knew that pressing her right now wouldn't get him any farther. "Alright." He looked into his own kit, nodded, then looked back up at her. "I'm ready if you are."

"Good. Let's get moving."

The burglary really was too easy, Grissom thought again as he packed the last fingerprint into an evidence envelope later that night. The fingerprints would take them exactly where they needed to go, with no puzzling required. He sighed, wishing that Sara would open herself up to him mentally as much as she had physically in the past few days.

God, he wanted a cigarette. Taking a deep breath and pursing his lips, he tried to focus on anything but that urge. It worked for a few seconds, until a voice from the doorway made him jump and scattered whatever concentration he had managed to gather. He looked up to see who had screwed up his latest attempt.

"Grissom?" Mark asked again, voice low and furtive.

"I'm right here, Sellers. And speak up." Grissom still couldn't make himself like the man who was so close to Sara. He fought a constant battle to keep himself from thinking he had been replaced by Mark.

Mark took a few steps into the room and took a seat on the waist-high counter, facing Grissom. "Can I ask you something about Sara?"

Red flags went up all over the place in Grissom's mind. Why did Mark want to know about Sara? "Depends on what it is. You ought to know that I won't gossip about her."

"I'm not asking for gossip. I'm just trying to get a handle on things."

Grissom shrugged. "Fine. So ask."

"Sara left Las Vegas and moved out here because of you, am I right?"

This was not the sort of question he felt comfortable answering. "I told you I wasn't going to gossip about Sara, Mark. Do you have something to ask that's more mature than junior-high level, or are you wasting my time?"

Grissom's hostility interested Mark. Always fascinated by the convoluted ways of the human mind, he had, for a time, considered applying for the FBI's Behavioral Sciences Unit before deciding that he'd prefer to not have lives hanging on what he thought a given person was thinking. He'd retained the instinct, however, and right now it was telling him that Grissom had some sort of reason for disliking him.

"Ok," he tried again. "Let me start with something more basic: tell me why you don't like me."

Grissom hadn't expected that question. "I don't dislike you," he managed in what was hopefully a confident tone. "I haven't known you long enough to like or dislike you."

"Nevertheless, you don't like me. In fact, the only one of us that you seem to really like is Sophie. The other guys you ignore for the most part. I, however, get the scowls and abruptness. I'd like to know why." When Grissom, predictably, just scowled at him, Mark added, "My question has nothing to do with Sara, so you can't use her as an excuse not to answer."

"I don't need an excuse to not answer!" Grissom exclaimed hotly. "I have no obligation to tell you anything!"

Mark blinked. "…Or does it?"

"Huh?"

"I had said my question had nothing to do with Sara, but listening to you, I'm not so sure now."

The cigarette craving hit Grissom again, this time even harder. His fingers clenched and his face, if possible, tightened even more. "I don't know why I'm still sitting here," he said, gritting his teeth. "In fact, I won't sit here any longer." He pushed himself up off of the couch he had been sitting on, snatched up his evidence envelopes, and walked past Mark and out of the room.

Mark thought for a few seconds. Yep, he decided, the reason Grissom disliked him definitely had something to do with Sara. He wondered what – had he offended her in some way, and she'd told Grissom? Was Grissom angry that Mark had been Sara's most frequent partner before he arrived? That sounded almost right, he decided . . . it had to be something like that.

Still pondering, he retraced Grissom's path out of the room. Well damn, now he just had to know what this was all about! He was going to have to corner the man again and drag the truth out of him.

Grissom handed over the last of the envelopes to the evidence clerk and turned to leave. He needed a cigarette, just absolutely needed it. Quitting was hard enough without all the stressors going on in his life right now. Especially the one named Mark. He didn't want to interact with Sara's . . . Sara's what? . . . bosom buddy, let alone get into a meaningful conversation with him. He hoped that he'd been sufficiently mean to keep Mark away from him from now on.