Brass travels to Hollywood, California to try to track down his estranged daughter's friend, meanwhile trying to rekindle some kind of relationship with her.

In the season finale, the CSIs wait by the bedside of one of their own when he's shot in the line of duty. One CSI faces a hard choice by having the power of attorney over their injured friend and colleague. Meanwhile, the team also investigates the strange way of life of one man when he is found decapitated by a train.

D.B. Russell leads the CSI team on a hunt to find Morgan and Ellie Brass following their kidnapping by a ritualistic killer.

The CSIs investigate a crime that has ties to a 25-year-old mob heist; Brass is faced with a decision when his daughter tries to commit suicide.