Catherine and Grissom drove back to CSI HQ in silence. Total silence. Catherine had tried to turn on the radio, even giving up her usual soft rock for some classical, but Grissom promptly flicked it off.

When Catherine parked the Tahoe, the engine had barely cooled before Grissom unbuckled his seatbelt and then got out of the vehicle, practically stomping into the building.

"Grissom?" Catherine called after him. "Grissom! GRISSOM?! Hey, Gil! Come on, I know you can hear me!"

But Grissom ignored her and kept walking. Catherine was miffed.

What had happened at Las Vegas Medical? He seemed perfectly fine when he'd left Catherine with Ines Dali. Had he seen or heard something?

Catherine now had two mysteries to solve—the Stop-n-Go, and what the hell was wrong with Grissom.

"Warrick, Sara, the Stop-n-Go robbery needs some extra eyes, ears and hands," Grissom said, coming into the breakroom. "I hope you were filled in while I was away and if not, get filled in—ask Nick. Since you two weren't in the field tonight, I'd like you to do some lab work. Sara, you have some fingerprinting to do and Warrick, Catherine's got a surveillance tape for you."

Sara and Warrick, who had been gossiping, turned and looked at Grissom as if he had three heads.

"What?" Grissom swiped at his nose with his sleeve non-chalantly.

"How was your dinner with Chloe?" Sara asked.

He cocked his head and gave Sara one of his infamous looks and then glanced at Warrick, wondering if he should answer in his presence.

"Sara was telling me the story," Warrick said quickly. "Pretty interesting."

"Sara, this is a personal matter of mine, not yours," Grissom said sternly after a small grunt of disapproval. "I don't want the lab to turn into the headquarters of the National Inquirer."

Blushing, Sara got up and poured herself some coffee and chugged it black.

"So you have a sister?" Warrick asked Grissom.

"Had a sister, Warrick," Grissom corrected. "She unfortunately passed on quite a long time ago."

"Oh yeah," Warrick was sheepish. "Sara told me she died of eclampsia."

"Did she?" Grissom crossed his arms and glared at Sara.

"Okay, you never told me it was a secret!" Sara exclaimed.

"If I wanted my life to be an open book, I would have left it on a table somewhere for everyone in the damn bureau to read."

Sara heaved a great sigh and hung her head. "Sorry…sorry."

"In answer to your question, Sara, dinner was fine. Despite your inability to keep secrets, you picked a good restaurant."

"Thanks," Sara perked up a little.

"Catherine and I are returning to Las Vegas Medical later tonight and talk to Marquita Dali and Adrian Lowe, two of the witnesses, if they're alert. Unfortunately, both were severely injured," Grissom said to her and Warrick, "so you can get me on my cell if you need me. Warrick? The tape. Sara? Fingerprints."

As soon Grissom stalked out, Warrick turned to Sara.

"Is he okay?" he said in a low voice.

Sara shrugged. "Nick says he was acting really weird over the phone. Maybe it's this whole thing with Chloe. It's getting him sort of…I don't know. He just seems very confused all the time."

"Slipping into dotage?"

"I heard that!" came Grissom's aggravated voice.

Sara covered her mouth and giggled through her hand.

Warrick bit the inside of his cheek and tried not to speak anymore.

"Is he gone?" Sara whispered.

Carefully peering out from the break room, Warrick nodded. "He's turned the corner."

"Whew."

"So…what was Nick saying?"

"Grissom said something about having no more surprises. He'd had enough of them, or something."

"That's all this job is," Warrick sighed. "Surprises."

Just then, Catherine walked by the break room, spotted Warrick and Sara and entered. "Either of you seen Grissom?"

"You mean Oscar the Grouch?" Sara wrinkled her nose. "He went that-a-way." The pointed her thumb down the hallway.

"Warrick, you're just the person I wanna see." Catherine delved into the cloth bag she was holding and withdrew the surveillance tape from Stop-n-Go. "I assume you know what this is?"

"It's definitely not a cupcake," Warrick said as Catherine put the tape in his hand.

"Unfortunately, no. Sara, down in evidence is a gun we found at the scene. Fingerprint it, analyze it, run it through AFIS like crazy, take it down to ballistics, have it classified…"

Sara nodded, "Got it."

"Did Nick brief you guys?"

"Yeah, he gave us everything before you guys got here."

"Good. The only thing I have to add is this: walk on eggshells when you're around Grissom, okay? He's moodier than a stepped-on hornet."

Warrick and Sara nodded and agreed.

"Let's get to work," Catherine concluded and left.

Nick Stokes was in the lab cleaning up from his experiments with the specimens from Pancha Nichols, Marquita Dali and the clay from underneath Mason Ziegler's fingernails when Grissom lumbered by, a scowl on his face.

"What's up?" Nick asked, trying to play it cool.

"Well, Sara's not going with you to Mason Ziegler's. Take Catherine."

"Why?"

"Because Sara wasn't at the scene."

"But—"

"I'm the boss around here, so just do it, alright?"

Usually Nick didn't mind Grissom's moodiness but right now his supervisor had a PMS attitude of a thirteen year old. Before he could open his mouth and retort, Grissom was gone.

Catherine was next to stop by, looking annoyed, but Nick called out to her anyway. "Hey, Cath?"

"Nick, don't speak to me unless you've seen Grissom. Don't even let those words escape your mouth."

"I have seen Grissom!"

"Oh…" Catherine was embarrassed. "Sorry. What'd he say?"

"You're coming to Mason Ziegler's place, once we find out where he lives."

"Ah, Mason Ziegler. The Bob Marley pothead. I thought Sara—?"

"Me too," Nick shrugged. "Grissom wants Sara to work on some fingerprinting."

"And I just put her to work with the classification of the gun I found, so I guess it's good she's not coming." Catherine paused. "Was that the right thing to say?"

"No, but I get your meaning."

"I'll check out where Mason Ziegler lives, check out employee records from the Stop-n-Go, call up the manager."

"Okay. You do that."

"And what are you going to do?"

"Mmm," Nick pretended to think hard. "Sit on my butt?"

"Come on, Stokes. Be sociable. Help me out with Mason Ziegler."

"Okay, okay. I'm coming."