One night, four cases. Grissom and Brass get a stolen hummer and a taco stand. Warrick gets a dead car show girl. Sara and Greg get a dead bodybuilder. Nick gets a dead boy found on a bench.

A high roller who spent the night with a woman he had just met is found dead on the loading dock of the casino where he was staying. The investigation reveals that the victim won $10,000 in a pool game and was an assistant to a respected movie producer.

In part one of this two-part seventh season opener Grissom and Catherine handle the case of a women's dead body found at Cirque du Soleil by a performer. Meanwhile, an investor at one of Sam Braun's new casinos is shot to death during a party on the rooftop. Catherine's life is in jeopardy after visiting a nightclub with Nick. Grissom finds a miniature replica of a crime scene that he is investigating.

While investigating an elderly woman's murder, Grissom receives a miniature crime scene replica; Greg attends a hearing to ascertain his culpability in a teenager's accidental death.

Several suspects in a murder case are UFO-club members who believe shape-shifting aliens have been working to conquer the human race for centuries

Two murders that happen during Las Vegas' annual bull riding rodeo are investigated by the CSIs, who find that the murders might be connected to illegal bull breeding.

A deer is illegally killed, and the person found with the body in the back of his truck apparently dressed it in a tutu. The man, who was completely drunk when arrested, was being interrogated by Nick and Brass, and suddently tries to escape and is pepper sprayed. Unfazed by the spray, officers then taser him and he bursts into flames and dies. Meanwhile an unbalanced woman wearing a tinfoil outfit at the front desk tries to warn people (including Nick) of an alien invasion. After observing the burning man, she later turns up dead with green-tinted blood. When other people turn up with the same problem, it's up to the team to figure out why. Meanwhile, an old couple dies, apparently in their sleep... but there is evidence the cases are related.

Two secretaries on holiday from Arizona attempt to steal a man's wallet and ATM pin number in a scam, and wind up dead in different locations. Meanwhile, the CSI team also investigates a disturbing medical mystery involving the dumping of human organs in a wildlife refuge.