The film thematically follows the stories of the TV series "30 cases of Major Zeman". We can meet Major Zeman again with Lieutenant Colonel Zitny, Major Hradec and Lieutenant Gajdoš. The film is set in 1972 in a South American country and shows the activities of an international counter-revolutionary headquarters, which the central character of the film - Major Hradec - uncovers even at the cost of his own life. The film was largely shot in Cuba. The film is an edited version of the series episodes 27 and 28 "Messages from an Unknown Land" and "Hostages in Bella Vista".