When wrongly accused former suspect Gene Farrow enters the Crime Lab covered in blood, wielding a cleaver and looking for Allie Rajan, the CSI team investigates his peculiar story about a macabre party with a fatal ending.

The CSI team investigates a murder case that hits close to home for Folsom - when he is forced to sit this investigation out, he does his own digging with help from Trey. Worried Folsom will do something he regrets if he gets his hands on the killer, the team members find themselves racing to arrest the suspect first.