In Palm Springs, a woman having car trouble finds a man's torso. Then a second man is dismembered, then murdered, a change in the unsub's M.O. Both victims were in relationships that recently ended. The third victim is gay, and the body is left in a more public area. The unsub, Mark Tolson, is also gay, and in a deteriorating marriage. All the victims are blond, healthy and slim, just like the unsub's estranged spouse, Bill Sievers. Tolson's next victim is another gay man, Wesley Parum, who was hitting on Bill. The BAU tracks down Tolson through a photo of him with Seavers at Parum's memorial. Tolson, whose dad was a butcher, trips up, and Bill figures out that Tolson was a killer. They struggle and Tolson knocks out Bill. Mark binds Bill and grabs his cleaver, but the BAU bursts in to save Bill. Spencer, who is frazzled and distracted, decides that bringing his mother to live with him was a mistake.