Grissom, newly appointed head of the crime lab, investigates the supposed suicide of a jackpot-winner. Meanwhile, Warrick has to deal with the fact that the shooting of rookie CSI Holly Gribbs was due to his failure to supervise her.

The search is on for a abducted woman while a hit and run death of a little girl is investigated.

A severed leg is found in a lake while a fraternity pledge goes badly.

A young man is found naked and dead in the desert.

The CSI team is summoned to investigate the death of the first-class passenger Tony Candlewell in twelve hours because of a jurisdiction problem. Candlewell has contradictory evidences of aggression and defense, and the first class passengers are secluded in the airport and interviewed. But Catherine and Brass note that they are hiding information. Meanwhile, in the autopsy, the coroner learns that Candlewell had undiagnosed encephalitis, the reason of his berserk behavior. When they find shoe prints on the back of his jacket, the passengers Lou Everitt, Max Valdez, and Dr. Kiera Behrle .are considered prime suspects. The team interviews the blind Mr. Cash that was near the incident and using dummies later, they represent the statements and come to a conclusion of the case.

While investigating the disappearance of Margaret Shorey at a supermarket, Grissom and Catherine stumble upon a serial killer who claims to have killed five women in supermarkets located along the I-15. Sara and Warrick are given the case of the death of a man who, his brother claims, was killed by a burglar. Sara soon suspects that the brother is not telling the truth. Nick is specially requested to solve a case of harassment.