A teenager is found murdered on a construction site. Grissom, Sara, and Warrick follow the lead of blood on a hammer. Nick, with an assist from Catherine, tries to find how a woman was killed by a gunshot on her lawn when no one nearby had a gun.
When Luke Horton disappears after a class reunion, the team initiates a search for him, and learn that Luke was living a double life and was finally ready to come clean.
