When two married couples are brutally murdered after being forced to have sex, the team investigates.

They profile an UnSub frustrated by impotence, who’s crimes follow the pattern of sexual fantasies he used to enact at swingers clubs.

More are killed as the man’s mental state deteriorates.

Garcia struggles to take over JJ’s responsibilities but ultimately helps identify the UnSub, leading the team to a tense confrontation where Prentiss uses herself as bait to keep the killer from opening fire on a bar full of civilians.