In the season finale, Warrick and Lou Gedda reunite, but the results are tragic when Warrick is framed in the brutal murder of Lou Gedda. Warrick is found with a gash in his forehead at the crime scene where Gedda is tied to a barber chair and shot multiple times. Warrick has no memory of how it happened. Grissom and the team fight to extricate him form this mess. Sheriff McKeen believes Warrick is guilty, and wants him to pay for the crime, but the CSI's find evidence of a mole in the department trying to frame Warrick.