The film takes place in the pre-war years. NKVD captain Frolov is investigating a sabotage at a chemical plant. Suspicion falls on circus performer Erwin Gross. However, the villainous murder of a clown suspends the investigation. It is only with the help of young circus gymnasts that Frolov manages to establish the truth...
| Actor | Role |
|---|---|
 Romualds AncansNot listed | Not listed |
 Pauls ButkevicsNot listed | Not listed |
 Givi ChuguashviliNot listed | Not listed |
 Fyodor DunayevskyNot listed | Not listed |
| OOlga BogachyovaNot listed | Not listed |
 Matyoqub MatchonovNot listed | Not listed |
 Mahmud IsmoilovNot listed | Not listed |
 Artyk DzhallyyevNot listed | Not listed |
 Oleg IzmaylovГюнтер Кох | Гюнтер Кох |