A mob of hooded criminals are terrorising the city by surrounding and beating up tourists. When Greg sees an attack, he becomes the gang's next victim.
A reality TV series follows the CSI team as they investigate a serial rapist who gained access to a woman's apartment by posing as a fireman.
As Grissom leads a group of college students on a tour of the CSI facilities, the stories behind four murder victims unfold, including a casino guard whose luck ran out.
The team investigate when a body is found inside a chimney, with the evidence leading them to re-open the unsolved case of murdered teen Caroline Fitzgibbons.