Bex races to catch Zack Lang, a class-obsessed serial killer who bludgeoned wealthy New Yorkers; when Bex notices a sharp contrast between his victims in the past and present, the team digs into Zack's unresolved trauma in order to stop him.

Two decades after his apparent death, cult leader and serial killer Noah Cyrus appears on the doorstep of one of his followers. Against the clock, the team races to stop Cyrus' plans, but everything is not as it seems.