Lives are on the line when terrorism strikes Las Vegas. Gil Grissom, Catherine Willows and Jim Brass return to help the team; meanwhile, Lady Heather surfaces once more. Big changes are in store for the future.

The season 5 finale was directed by Quentin Tarantino. In this featurette, the CSI cast and crew recount Tarantino's work while the director discusses the episode.

Grissom and Catherine investigate when a leg is found severed from a body in a lake. Sara and Nick investigate a fraternity pledging gone terribly wrong.

Grissom and Warrick take the case of a young man who is found naked in the desert without an obvious cause of death. Sara gets to find out why the body of a woman who was buried the previous week is now in a dumpster. Catherine and Nick investigate the killing of a school's dean.

Catherine violates department protocol when she takes the case of a rape accusation against her ex-husband. Warrick and Sara search for the missing bullet that will either exonerate or indict a cop for murder. Grissom and Nick investigate when a female skeleton is found buried in cement under a house.

When a teenager and her sister are the sole survivors of the gruesome murder of four members of one family, Grissom and his entire team investigate the crime. What initially looks like a bizarre cult murder becomes more disturbing when they discover the motive behind the massacre.

3 months after the murder of a man, in a scene staged to look like a suicide, another similar murder occurs. Warrick and Nick investigate the case of a man who drove over a cliff and is now unconscious.

Grissom and his team investigate the death of a first class passenger on a flight to Las Vegas.

Grissom and Sara investigate a bug-riddled body found in the desert. Warrick and Catherine look into the theft of valuable art. Nick investigates when a missing woman's car is found at a bus station. Warrick is suspected of having gambled on duty.

A woman is abducted from a supermarket, and Grissom discovers chilling news on a bathroom stall door. Warrick is caught in a casino on duty, and is then paired with Sara to investigate the suspected murder and robbery of a man who is identified as Warrick 's brother.

A man convicted of arson and the murder of his wife and child seeks assistance from Grissom to help prove his innocence. Catherine and Nick investigate the underground world of sports gambling when a teenager is murdered.

A bomb explodes in an office building, and the chief suspect is a security guard. Nick helps his prostitute friend again but, after giving in to his passion, she is found dead the next morning.

When a single human bone is discovered in the desert, Grissom and Catherine must cover miles of territory to find the rest of the skeleton. Warrick and Sarah trace the death of a male stripper to members of a wedding party who may have celebrated a little too hard the night before the nuptials.

At a swanky fundraiser, a woman is discovered dead in the pool. Warrick looks into an apparent professional hit inside the glass elevator of a hotel.

A woman is abducted from a mall parking garage, then raped, beaten, shot and left for dead. Catherine and Warrick are given boxes of evidence from a shooting that goes to trial in four days, and they must re-prove the case.

In an apparent interrupted burglary, a body is found in a pottery store. Sara and Warrick investigate the case of a woman mysteriously burned to death in her home.

A couple celebrating their anniversary, are killed while leaving a restaurant, and their car is stolen. Catherine investigates the collapse of a city-owned residence that kills three elderly women.

The entire team investigates the abduction of the infant child of a wealthy family, and suspicion immediately falls on the child's parents.

Two women run over a deaf man who was dead before he was hit. Catherine and Nick investigate an apparent mob hit that leaves five dead in a coffee shop.

Grissom, Nick and Warrick are called in when a jogger is killed by a wild animal in the park. Catherine and Sara investigate the death of a six year old girl at a carnival.

While Grissom and Catherine investigate the case of a human head that is found in the trunk of a car, Sara and Nick have a case of a body in the desert that's missing it's head. Warrick looks into a murder in a juvenile detention facility.

The team investigates the string of murders by a signature killer who has knowledge of forensics. Sara offers to bait the killer.