The secret police agent finds that factory director wife is counterrevolutionary but dies from the heart attack. The director reads the diary of an agent and turns his wife to police.
During the Russian Civil War, orphan Fyodor (Fedka) Trofimov, whose father was killed by Whites, is adopted by a Red cavalry unit.
About the childhood years of the hero of the Civil War, Marshal of the Soviet Union Semyon Budyonny.
