The television adventure film, based on Verne's novel of the same name, Twenty Thousand Leagues Under the Sea, tells the adventures of three shipwrecked prisoners aboard the legendary submarine Nautilus.

"At the turn of the 10th and 11th centuries Boleslav's kingdom fell apart in the fratricidal war between the Premyslovci and the other clans the main profiteer of this being the German emperor. At that time it seemed as if the Czech state and the lineage of its princes was awaiting its end..." It is with these words that the tale of this film begins, whose narrative is based upon the the play by Frantisek Hrubín of the same name.

The main character of the story which takes place in the twenties in Budapest is the poet Dr. Rácz György, who returns after ten years of absence. In a café he meets his former friend Lajos, who has just broken up with his lover, Márta, because of the wife of professor Büchler. The transiently formed, rootless Rácz gets entangled into the sophisticated, complicated love affairs of bored or tired ladies.

An escaped inmate of a mental home, Franz Moose, has been found shot dead in the forest. In the course of their investigation, District Commander Havel (Jirí Adamíra) and Lieutenant Mares (Miroslav Zounar) slowly work their way through the complicated case. Havel learns from the employees' testimonies that Moose was facing trial for war crimes before he was finally sent to the hospital. There he shared his room with Kozdera, spent his time painting, and made several attempts to escape. Havel wants to interrogate Kozdera but the unfortunate patient gets killed before he can do so.

Marek (Jirí Holý), formerly a driver of a long-distance lorry, has served his term for smuggling art works abroad and is released from jail. Years ago, he sacrificed himself and confessed his guilt on behalf of his companions - the drivers Krása, Jelínek, Hess and Novák from the Ministry of Culture who gave them tips. Marek finds Hess and tells him that now he expects the gang to compensate him for the wasted years of his life.

Czechoslovak film from 1952