1960年，克萊維爾州。從不失手的小偷德伯力克，真實身分不明，他再度出擊，以巧妙的伎倆逃過警方的埋伏。此時，鎮上正期待著康德夫人的到來，她是風情萬種的女繼承人，將帶著著名的粉紅鑽石前來。這無價珍寶當然逃不過德伯力克的眼睛，德伯力克意圖竊取，卻被康德夫人無可抗拒的魅力迷住了。這惡名昭彰的小偷正處於危險之中，探長和他的團隊終於想到方法將其引出，這次德伯力克將無處可逃。

Diabolik narrowly escapes Inspector Ginko's latest trap, leaving his partner in crime Eva Kant behind. Furious, Eva offers Ginko her help in capturing him, but the former has to face first the return of an old flame of his, noblewoman Altea.

Captured by a ruthless gang of bank robbers, foes Diabolik and Ginko find themselves facing certain death. While Eva Kant and Altea forge an unlikely alliance to rescue their lovers, Diabolik reveals his mysterious past to the Inspector.