Soviet propaganda film about Alexei, a village boy who comes to Odesa to earn money in 1901. While still on the train, the hero gets acquainted with a young worker Mitya and witnesses the arrest of the underground leader Savva, who distributed Lenin's newspaper "Iskra". The boy quickly gets used to the city, learns that one must fight for one's rights, and becomes one of the most active Leninists in Odesa.