The plot centers on the people who began to form underground groups from the very first days of the occupation of Minsk: oil engineer Isa Kazinets, soldier Ivan Kabushkin, student journalist Vladimir Omelianuk, medical professor Yevgeny Klumov, party and Soviet worker Sergey Blagorazumov, and others. Their main weapon was their hatred of the occupiers. Soon, the underground fighters managed to establish contact with the partisans, and they began to plan joint operations.