Nanni Vitali, a sadistic and ruthless criminal, breaks out of prison along with three other violent thugs. Together, they unleash a horrifying wave of murder, robbery, and sexual assault. Among their victims is the terrified Giuliana Caroli, whom Vitali kidnaps and torments. Meanwhile, the relentless Inspector Giulio Santini is on a mission to track down and capture the vile Vitali, determined to bring an end to the madness unleashed by the brutal quartet.