Early years after the revolution of 1917. 15-year-old Igor Stupin is going to Rostov to give a document to his brother, who saves him from military conscription. During his trip, the boy sees the harsh truth about demoralizes officers, executions of fugitives and the retreating of the White army. On his way back, Igor agrees to pass a letter to his friend. This reckless act changes his life dramatically, as the letter contained a secret signal to start the proletarian uprising in his hometown…