The captain of the Prague shipping company, Adam Korkorán, lives his dreams of commanding ocean liners, even though in reality he only sails a small steamer on the Vltava River. The company's management still has problems with him, so when Korkorán refuses to retire, they at least send him to a spa. However, at the train station in Poděbrady, a servant from the most expensive spa hotel accidentally takes away his suitcase with the luggage of a rich lady. As a result, Korkorán is mistaken for a corvette captain and a rich man. Dazzled by the luxury, Korkorán befriends a retired admiral and begins to play a game with the spa guests and himself. He is even declared the most popular guest of the season. When he runs out of money, he writes to his housekeeper to send him all his savings. The horrified woman decides to go to Korkorán, and the truth comes out...