After years of evading capture, Gacy and Bundy are finally brought to justice as they both face punishment for their heinous crimes. Meanwhile, the Green River Killer is still at large and becoming more of a threat than ever; Dahmer struggles to resist his murderous urges, and BTK has also gone silent while he raises a family.

Après plusieurs années de cavale, Gacy et Bundy sont arrêtés et condamnés pour leurs crimes. De son côté, Gary Ridgway continue à échapper aux forces de l'ordre. Dahmer, lui, tente de résister à ses pulsions meurtrières tandis que BTK a mis un terme à ses tueries.

Gacy og Bundy blir til slutt arrestert, men Green River Killer er fortsatt på frifot. Dahmer prøver å undertrykke sine morderiske drifter, og BTK stifter familie.