There are mysterious murders in the area of ​​Lake Balaton. These places are shrouded in secrecy and constantly attract hunters: during the Second World War, the Germans had hidden a huge treasure here. Investigation of the murders entrusted to Major Kardos. He takes up the case, but in search of treasure he had many competitors. Kardos uses help from his loyal friend - a policeman-superman Etvash aka "Droplet".

The movie version of Endre Fejes' short story is based on a case that happened in the early 1960s. A psychopathic working-class boy changes his identity for a few days on his hard-earned money. He pretends to be a Greek diplomat, pays for luxurious dinners, courts elegant women, and of course, always disappears before the engagement. But he falls in love with the beautiful Zsuzsa Christmas and can't leave her in time.