An American millionaire has just died. His sole legatee is a youthful indiscretion, a girl who is currently living in Italy. Two private eye detective agencies, in competition with each other, investigate. Combining business with pleasure, they search sunny Italy, but they only have one clue to find their heiress: she has three moles on the buttock. One of the private eyes falls in love with a gypsy who sings in nightclubs.