Operation Holtsauga was a Nazi plan to destroy Soviet ships and aircraft approaching Murmansk, which was carried out in 1942. Near Bezymyanny Island, a Soviet ship struck a mine and sank, and engineer Okulich, who miraculously survived, was taken prisoner. However, he managed to escape and even took German officer Ritter with him. During a week of difficult travel to the mainland, he learns from the German about the Holzaug plan. Thirty years later, an explosion occurs on Bezymyanny Island durin...