Distracted by an attractive passenger, an Indian taxi driver feels his cab strike something at a suburban intersection. When he gets out to check, he finds a teenage boy pinned beneath the left rear tire, apparently killed on impact. The cabbie jumps back into the taxi to call for help, but a mob of angry onlookers - all of them white - drags him out and beats him for the crime. When Grissom arrives on the scene, he discovers that the teen has been eviscerated and has stab wounds, but shows no signs of having been struck by the cab.

A severed head is shipped to Dr. Robbins from Jackpot, Nevada. Grissom goes to Jackpot to find the rest of the body and gets very little cooperation from the locals. Catherine gets an unexpected gift from her father.

Warrick's appearance at the preliminary hearing on a rape and murder case goes terribly wrong when the only piece of evidence is thrown out on a technicality. Grissom and the team have 24 hours to make the case with new evidence or the killer will go free.

Grissom and Sara investigate the murder of a woman after a swap party. The married couples in the neighborhood meet and switch partners. With the help of a crime scene cleaner, Nick and Warrick find there was more to their crime scene than they first thought. Catherine wants a promotion to day shift supervisor.

A serial killer strikes again, and the CSI team tries new technology using evidence from a prior killing. They find a fingerprint belonging to Jesse Acheson, who becomes the prime suspect. A boy confesses to the killing of his brother, but evidence suggests that he may not have committed the crime.

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.

The two forensic teams come back together under the leadership of Grissom and Catherine just in time to tackle three separate investigations: a murdered couple found in bed in a suspicious trailer explosion; a beautiful stripper discovered dead and dumped in the worst part of town; and two bodies found baked and decomposed after spending five days in the trunk of a car exposed to the hot Vegas sun, forcing the CSIs to ""wrap"" up the evidence and bring it back to the lab for further analysis.

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.

After a man is killed in his limousine, Greg finds that the murder victim has ties to the man he had to kill in self-defense. The team finds that the brother is involved in this investigation and has to deal with him and his hostile mother.

Grissom investigates when a sadistic client tries to murder Lady Heather (Melinda Clarke), who makes the probe more difficult when she refuses to name her attacker. Also, Grissom's reunion with Lady Heather makes Sara uneasy.

As the CSI's continue their search for and discover the identity of the "Miniature Killer", Grissom and Sara's relationship gets exposed to the rest of the team as she goes missing during the investigation. The "Miniature Killer" is finally captured, but not before a member of CSI becomes the killer's final victim.

Sara questions her future as a CSI when a past case comes back to haunt her, the 12 year old Hannah, who has to back up her brother one more time with all new tricks up her sleeves.