Four prison escapees - led by utterly mad leader Nanni Vitale (Berger) - embark on a spree of rape, murder and revenge on those who imprisoned them. Dedicated policeman Santini (Harrison) pursues the vicious killers to the end. Helmut Berger (1970's Dorian Gray) is always interesting to watch, and here he's terrific as the wild psycho, revelling in the delirious dementia of the role.

Beautiful Marisa Mell (Seven Blood-Stained Orchids) is cast as the woman drawn into the terrorists' web of retribution.

Also known either as Mad Dog Killer or as Ferocious. Italian title: La Belva col mitra.