Nick and Keppler investigate the bizarre world of the black market sales of body parts after they find a body that has been burned and the organs removed. The rest of the CSI team investigates the death of rich woman who was killed in her own home.

Hodges stages hypothetical murders in the lab in order to give his fellow lab techs a chance to play CSI, but unbenownst to them he has other motives behind his actions. Meanwhile, after Sara's farewell, everyone tries to comfort Grissom.

A cache of missing chips from a closed down casino turn up in Vegas and a string of murders follow, leading Langston to use deadly force for the first time in his career as a CSI.

When a policeman kills another officer, the CSIs must look to the evidence to determine if the shooting was premeditated or an accident.