Lupin and company are taking a summer vacation on Miami Beach. Suddenly, a helicopter appears in the sky overhead, its passenger shouting something about Lupin having placed a call saying that he was going to raid Miami Bank. After that comes a phone call asking them to raid the bank, adding the strange proviso that if they do, then Miami Bank will join the ranks of the country's best. So, Lupin agrees, for the moment. Though he takes a shot at cracking the vault, it turns out to be empty. The bank becomes very famous for not having had a single cent stolen. And they plan to hold an anniversary celebration next year on the same date.