Children of Varnu Street whose fathers work in nearby factories face the "Tuliana Empire" - a group of boys, children of merchants from the nearby Lauku Street.

Captain Jack, this is actually an ordinary girl, she is an informal leader among the boys, loves the sea very much and spends a lot of time on the decommissioned ship Signal. The film tells the amazing story of the Signal team, which during the war saved the lives of Soviet prisoners of war, among whom were Gunar and Mitya.