Captured by a ruthless gang of criminals, the legendary master thief Diabolik and Inspector Ginko find themselves face to face, both locked in a cell with no way out. Certain of facing an inevitable death, Diabolik decides to talk. Without hesitation, he reveals to his archenemy that he grew up on a mysterious island, inhabitated by the most brilliant criminals of every metier. Meanwhile, Eva Kant and Altea are desperately looking for their men. Will the paths of the two rivals cross again?