Based on the novel of the same name by Harry Turk. 1944. In occupied Poland, a railway line is being built to transport lead ore to Germany. The Valley of Seven Moons is restless, with construction materials disappearing and people vanishing. The occupiers feel uneasy on foreign soil. Despite increased security, partisans carry out one act of sabotage after another, hindering construction in every way possible. The German Rudek and the Jewish girl Martina, who at first stand aside from any struggle, join the partisan detachment.