Moskva River, Baltic and White Seas. Karelian landscapes - forests, lakes, rivers, waterfalls. Prisoners work in logging and felling. Prisoners and Red Army soldiers on the construction of the Baltic-White Sea Canal (earthworks and mechanized work); laying of explosives, explosion of a bulkhead, opening of one of the airlocks. Construction of the canal at different times of the year. Canals, locks, dams and other structures. Reading room and topography work. Awarding the best canal builders with orders and medals. Transfer of railway tracks. Life of the Red Army. Completed construction. Visiting the canal I. Stalin, K. Voroshilov, S. M. Kirov and others. Meetings of builders. The movement of ships along the channel.