A masked criminal mastermind known as Diabolik continues his audacious career of theft and deception whilst navigating a complex web of personal loyalties and dangerous rivalries. The film explores the origins and dual identity of the iconic Italian comic-book anti-hero, delving deeper into what drives the elusive thief beneath his cold exterior. Romantic entanglements and the relentless pursuit by law enforcement once again place those closest to him in jeopardy.