As Grissom takes a group of university students on a tour of the lab, Doc Robbins carefully sews a female corpse back together after an autopsy. David brings the body to the cooler, where moments later the body sits up. She's confused for a moment until the body next to her sits up as well. They introduce themselves, and our first victim is Donna Basset, who isn't sure how she ended up in her current circumstances.
Luckily, Catherine and Brass are on the case. The victim, Donna, was found in an elevator of a hotel by cleaning staff, and white cotton fibers are taken from the scene. An American Beauty rose petal is found behind her head, and when the body is turned, water spills out of her mouth. "How do you drown in an elevator?" Brass wonders.
Catherine does a floor by floor search for anything suspicious and finds matching white fibers in the penthouse. Inside a housekeeping cart, Catherine uncovers clothing, and more importantly, a gun in its holster. "We've got a dead cop," she tells Brass and the hotel manager as they approach. Donna might have been moonlighting as security for Mr. Hsing, a 'whale' just in from Hong Kong who is staying at the hotel. He's an architect and feng shui expert who likes the hotel furniture adjusted per his instructions.
In the bathroom is a tub with rose petals scattered around it. Towels are missing, but otherwise the room is untouched. Downstairs Mr. Hsing is playing Baccarat alone with a dealer, and he's winning. He seems distressed when he hears about the murder, since Donna has worked for him before. And though often wealthy men hire security for show, Hsing assures Brass, "I have very real enemies." He only left the player's room once that night, to try and change his luck (by changing his underwear).
Robbins tells Catherine that Donna definitely drowned, and someone held her down in the tub. But she put up a fight. When she was rolled into the elevator car, the killer knew cameras would catch him, so he didn't show his face. But it's possible he left something of himself behind on the rose petals. Catherine tests them all in the GCMS in the hopes of finding something.
When she and Brass head to Hsing's room, they find him ready to depart for Hong Kong. Catherine wants to see his clothes to look for grapeseed oil found in the rose petals. The oil was in Hsing's tub; maybe it's on his shirt too. Unfortunately, the shirts have already been cleaned, and Mr. Hsing is smug as he hands them over. "Ship them to me in Hong Kong," he says.
But Catherine is one up on him, from a suggestion Grissom gave her. She's able to put together full prints from the elevator's partials, and Robert Hsing's name comes up as a match. Looks like when he came back to the room to change his luck, he found Donna relaxing in the bathtub. He was furious, thinking she was the reason he was losing, and drowned her. Back in the cooler, Donna's disappointed she couldn't see danger coming. But her new friend Rebecca has a different story. Her luck with men was always bad, until one day, it changed. Or so she thought.
Rebecca's body is found at the base of a cliff in Red Rock, having fallen while her husband Gavin photographed her. Warrick and Greg rappel down the mountain, taking evidence as they go. David discovers the brain missing, and Greg is amazed to find the organ intact a few yards away. He also finds the woman's phone.
The husband, Gavin, is devastated. "This was supposed to be our second honeymoon," he tells Warrick. He thought he was out of his league when he met Rebecca -- she was a model -- but they were happy, judging by the pictures of the two of them. He had to hike to get help because there was no cell reception in the canyon. Rebecca's body was pummeled on the way down the rocks, but a broken middle finger makes Warrick wonder if someone stepped on her hand as she hung from the cliff's edge. He and Sofia question Gavin when the tox screen comes back reading that Rebecca was not only on an anti-depressant, but that she'd been drinking on the hike. Gavin knew she was depressed, but didn't think twice about bringing the wine to celebrate on their outing. Sofia implies that their marriage might not have been so rosy, and Gavin breaks, admitting Rebecca had been drifting away from him. She jumped off the cliff, but he didn't want to tell anyone. "Would you want people to know your wife would rather be dead than spend another minute with you?"
Warrick buys the explanation, but thinks that Gavin caused harm whether he pushed her or not. Could he have encouraged her to kill herself? Warrick copies Rebecca's cell phone drive in search of more evidence, which he finds in spades. Rebecca's phone recorded Gavin's attack, all the way up until the moment he stepped on her hands on the cliff. Gavin's response to the accusation: he did it. "You try having a hot wife. You pay for it every day."
As Rebecca finishes her story for Donna, another body is wheeled into the cooler -- it's a young man named Jack, looking for his wife and daughter. Relieved they're not there, he tells Donna and Rebecca, "I thought the war was hell until I came to Vegas."
The CSIs start off dealing with the body of a man who rammed his car into a police cruiser at full speed. The officer who worked the accident made sure to preserve evidence, which Nick takes from the car. Robbins check outs the body of Russell Caris. Though he has no bleeding wounds, there's blood on his hands and the steering wheel, not to mention a bloody knife in the back seat. When Sofia calls it in, she gets word immediately that the stabbing victim Russell killed is at a gas station.
Jack was getting gas with his family in the car, and the violent attack was totally unprovoked. He didn't know Russell, and even tried to hand over his wallet. After serving two tours in Iraq, Jack had just met his new baby daughter. Who knew the streets of Vegas could be tougher than a war zone? Robbins finds that the killer had been exposed to a toxic substance, either a poison or a drug that damaged his bronchial passages. Nick assumes drugs, and is surprised that the only drug that comes back in the tox screen is THC, found in marijuana. Pot doesn't usually cause that kind of behavior, so Nick looks more closely at the killer's car. He finds what's left of a joint and has the rolling paper checked out. Henry finds out that the joint was dipped in, of all things, embalming fluid. The fluid makes the marijuana burn more slowly, giving a longer high.
Jack's wife Cara now has to deal with the fact that the murder of her husband was a random event. Nick can only say the familiar words, "I'm sorry." But in the cooler, Jack is smiling, content. "I got to hold my baby girl."
Another victim, however, is not so content. He awakens in a snit alongside another man who's missing an arm, which makes it tough for him to light his cigarette.
Grissom and Sara approach a Vegas garage to find a shocking scene: two men dead, one missing an arm, and a chainsaw between them. Blood spatter is everywhere, and Sara takes prints as Gil photographs the scene. She thinks there's a third party who committed the murder, but it's hard to tell at this point. The man missing an arm is Ray Gaynor, a neighbor, and the other lived in the house, Lou Beltran. Lou is carved right across the torso, but the way the chainsaw teeth bit into the flesh tells Grissom that Lou might not have been facing his attacker when he was killed.
Brass discovers that Lou was involved in a divorce, and he cut everything up with a chainsaw that was going back to the ex-wife, Julia. Julia's got a rock-solid alibi as a flight attendant on the job, and though she didn't kill him, she's sure not sorry Lou's dead.
Sara and Gil set up a scene to reenact the deaths, and in looking at the spatter patterns, there was no third party involved. Ray probably rushed in to stop Lou from chopping up the furniture, and the combination of a dull blade and inexperience caused Lou to cut off Ray's arm. The saw kicked back, right into Lou's chest, killing him.
The cooler is now silent, the six bodies lined up in a row. The stories of each victim are complete, and Grissom explains the lessons learned from the cases to his university students. When a young woman asks why Grissom does the job, the answer is simple: "Because the dead can't speak for themselves."