Grissom and his team investigate the death of a first class passenger on a flight to Las Vegas. The investigators are forced not only to examine the physical evidence, but also to interview all of the first class passengers to get their personal accounts of the incident.

At a swanky fundraiser, attended by the sheriff, a woman turns up dead in the pool. The owner of the house is away and a young couple is housesitting. Warrick looks into an apparent professional hit in the glass elevator of one of the hotels.

Grissom and his team investigate a casino heist during which innocent victims were shot, while Catherine and Sara are called to the scene of a murder in a remote part of the desert.

Grissom investigates the murder of two men that leads him to a new encounter with Lady Heather. Catherine is desperate to find out what lead to the near death of her daughter and why her ex, Eddie, disappeared.

Nella continuazione dell'episodio precedente, alcuni indizi portano Grissom, Warrick e Nick a sospettare che dietro gli omicidi si celi la figura di un poliziotto. Contemporaneamente, Catherine e Sara cercano di scoprire quale mistero si nasconde dietro all'uccisione di uno studente il cui corpo viene ritrovato in stato di decomposizione dentro una vasca da bagno.

Quando un'autobomba uccide tre persone davanti a un casinò, lo sceriffo di Las Vegas Rory Atwater, vera spina nel fianco dell'unità CSI, sospetta immediatamente che si tratti di un feroce atto terroristico. Grissom è però di un altro avviso, e intende dimostrare che dietro la strage si nasconde un altro movente. Intanto, Sara e Warrick hanno il compito di scoprire chi ha ucciso la moglie di un noto cantante di Las Vegas.

The whole team must investigate a crime where a husband and his porn star wife were murdered execution style. Things get personal for Catherine when Grissom talks to her about her evaluation. Brass believes that Sara may have some type of problem.

Two men are found murdered after scamming Sam Braun's casinos. Grissom and Warrick investigate after Catherine is thrown off the case. One of the suspects is the son of a man Braun caught cheating. Nick gets the promotion that Sara coveted.

A casino employee is beaten and raped on her way home from work, but she survives and identifies her attacker. Unfortunately, a DNA test sets him free and Grissom must wrestle with whether evidence can ever lie. Later, Grissom comes to the rescue of a coworker who ends up on the other side of the law

Dopo aver saputo che Nick, un membro della squadra scientifica, è stato rapito e sepolto vivo, tutte le squadre si uniscono per cercare di salvarlo.

Dopo aver saputo che Nick, un membro della squadra scientifica, è stato rapito e sepolto vivo, tutte le squadre si uniscono per cercare di salvarlo.

At Keppler's request Catherine uses a different approach to catch the killer, and in doing so she deceives the rest of the CSI team. The team soon discovers that something is amiss in Catherine’s investigation.

Grissom returns from his sabbatical; Keppler is put into a compromising position when the bodies of a Trenton police officer and a hooker are found in a hotel room. The man who found them is a retired New Jersey cop and close friend to Keppler, who doesn't reveal their relationship.

The CSI team investigates a mad slasher who strikes without leaving a trace -- because he wears a form-fitting black latex suit that leaves not a molecule of evidence behind