Greg is doing his final proficiency test and he has a case to solve. Ironically, he investigates the death of a Sherlock Holmes- wannabe, obsessive to the point of recreating the great detective's living room in his home. He died from a close-range gunshot wound. The murder weapon is not found in the scene although everything other pieces of evidence suggest that it was a suicide. Working under Catherine, Nick and Warrick works on a case of a dead guy found in his car which veered off the highway. Dr. Robbins cannot find the cause of death and it is left to the two ...
A severed head of a woman, her hair brutally ripped off, is left in a newspaper vending machine. Found inside her mouth is a snake from Mexico. The murder fits the lyric of a Mexican song. The second case involves a dead salesman found inside a van with a wheelchair left behind in the back. The wheelchair belongs to a dead woman.
The bodies of two women are found covered in tar in a pit. The body in the bottom part of pit cannot be identified. The one on top was a mail-ordered-bride who died approximately 2 years ago. The prime suspect is her husband who claims that she disappeared and has already 'purchased' a new Asian wife.
A Lexus belonging to a young mother is found with a flat tire on the highway. The body is later found. Another case involves the death of a hunter from a bear. The bear, after attacking the man, also died. Investigations reveal that the bear, Tippy, was purchased by a broker claiming to be representing a zoo.
Bruce Eiger, a powerful Las Vegas casino mogul, is found dead on his front steps. The media is all over the case. Ecklie assigns Grissom to the case despite it being official Catherine's. Eiger had a dark secret. He liked being treated like a big baby.
Catherine, Warrick and Nick investigate a shotgun killing in the desert. What they come across however is a beaver dam full of money. When they subsequently learn that the victim worked at setting the spread for sports betting, they think he may have a betting scam of some sort. Grissom, Sara and Greg investigate a death in a hotel where someone is found suffocated in his bed. He was staying in a hotel hosting a convention for overweight people and was quite popular with the ladies.
A female flight attendant is brutally raped and killed in her hotel room. Ecklie brings a five-year-old cold case to Grissom and his team which bears a striking resemblance to the new case. Catherine's team investigate the death of a young boy in his own bed. He was beaten to death while his parents and older brother were in the house.
Greg, Sara, and Gil Grissom investigate a scene of bush fire which led to the death of man and the 3rd degree burn of another woman. Catherine, Nick and Warrick solve a case involving the death of an entire family. The father is found dead, apparently from a suicide, on his bed. The mother was shot while running downstairs. Their little daughter drowned to death in the pool.
This episode chronicles four crimes which are in themselves interconnected. One involves a stolen Hummer truck which was recently won by a couple from a convention where a dead woman was found. Prior to this, one of the convention's employee walked in on her dead trainer inside his very secured house. Lastly, the body of a twelve-year-old boy was left on a street bench.
Captain Jim Brass journeys to LA after Ellie asks for a favor in investigating her friend's disappearance. There, with the help of Warrick who is in LA for a conference and a friend in LAPD, Brass finds his investigation interrupted by higher powers. While he and Warrick ultimately are able to find Ellie's friend's murderer, he is unable to bring the perpetrator to trial. Disappointed, he leaves LA and return to Las Vegas.
Sara accompanies Grissom to a mental hospital where one of its inmates has been murdered inside his room. Interviewing patients prove to be harder than usual as most of them are mentally unstable. While the two CSIs are there, they uncover more than just the crime. One of the most shocking discoveries involve a patient with a dark childhood, which is still haunting him, and a nurse with a secret.
After an exhaustive day, Catherine stops by a bar where she has a fling with another customer. As she is leaving, he gives her his number on the bar's match box. Later on that night, Grissom calls in for a favor as he is short on staff. A woman was murdered. Prior to her death, she was seen with the same man who was hitting on Catherine in the same bar. A similar match box with a phone number inside, found on the victim, further points to this man as the main suspect.
Greg and Sara work on a case of two university students who mysteriously end up dead in a dorm room. Catherine, Warrick, and Nick investigate the death of a man found in what looks like a crop circle. With everyone busy on cases, Ecklie must work on a case himself. Unfortunately, the body disappears from the morgue.
The CSI Nick Stokes is kidnapped while investigating a crime scene and buried alive in a glass casket by his kidnapper. The Las Vegas Police Department receives a package with a tape and a hardware to permit watch Nick inside the casket, together with a request of one million dollars cash to release him. The mayor refuses to pay the ransom, but Catherine Willows asks her wealthy father and gets the amount. Then Gil Grissom schedules a meeting with the criminal to deliver the money and be informed where Nick is.
Gil Grissom meets Nick's kidnapper with the demanded ransom of one million dollars cash, and the man surprisingly blows himself up without revealing the location of Nick. Without any lead but the thumb of the criminal, the CSI team discloses his identity and the reason for such act of desperation. Fighting against time, the investigators give their best effort trying to locate Nick.
A UFO cult commits mass suicide in an underground complex shortly after apparently dumping a body in a garden. When the CSI team discover their bodies, they suspect two members are still alive and go looking for them.
With Grissom teaching at a conference, Nick Stokes and the remaining CSIs investigate a murder of a family in a house in a small town outside Las Vegas. In the house there is evidence of violence, blood and gunfire. The rest of the team thinks that the entire family was murdered, but Nick has the feeling that the little girl, Cassie, is still alive. So they start investigating and discovering the motive why the family was murdered (an illegal green house full of pot) and a chew gum in every place they go for searching clues. So Nick believes that Cassie left them ...
The CSI team is called to help when Karen Mathews reports her son, Jesse, missing from a playground where he was playing on the swings. Witnesses report seeing a man with a blue baseball cap near the swings. Clues in the park bathroom include blood and the boy's underpants. The boy is eventually found in a store, accompanied by a woman with a man fitting the earlier description. But the couple with the boy claim that he is their son Adam, while Karen insists he is her missing son Jesse.