The CSI gang investigates the murder of a young woman who seems to have been thrown in front of a speeding bus. A hand print on her back matches the victim's boyfriend, Jay Seaver, making him the lead suspect. The suspect informs the team that he has a psychotic admirer named Claudia, who he feels is killing to please him. But when it is revealed that Jay has hired a lawyer for Claudia, Horatio believes he has a bigger part in the killings than Jay is admitting. When another man is found dead at the base of an elevator shaft, evidence leads to one killer.