It all starts in 1985. In a small town there are three boys who dream of a career as a naval officer - Sashka Robertson, Leshka Balunov and Vovka Titov. The submarine K-963, on which their fathers serve, is leaving on a secret mission - to the NATO exercise area to find and record an acoustic portrait of the newest, virtually silent American submarine. And the boys, playing submariners in an abandoned factory, fall into a death trap. Years later, when friends Sashka, Leshka and Vovka were finishing school, military service no longer seemed so prestigious to many, values ​​changed, and submarines rusted. Vovka leaves for Moscow, becomes a businessman. Lyoshka goes to the Marine Corps. And only Sashka remains true to his youthful dream and connects his life with the sea - he becomes a submariner..