Sea convoys during World War II made it possible for Britain and Russia to keep fighting Germans. The sailors that were running the convoys were put under unbelievable strains - U-boats, planes, warships were trying to stop them.
After their tanker was sunked on Atlantic by German U-Boat, crew members take part in another risky journey - large Allied convoy to Soviet Union aboard brand new Liberty class ship.
Four young cadets decide to switch from merchant navy to U-Boats after their ship is sunk by British airplanes.
War films are not always showing the war per se - often the main theme is the influence of the conflict on lives of people involved, but also their families and friends. War is seldom a local thing - the trauma, the pain, the death they put their mark on people from around the world.