The river level rises, the dam can no longer hold back the floodwaters – it breaks. Panic erupts, everyone tries to save at least some of their belongings from the rising waters. Those who manage it flee to the farm of old dike captain Doorn. His sons, Peter and Heinrich, help wherever they can. In doing so, they save the local schoolteacher and his beautiful daughter, Renate, from certain death. Both men love Renate, but this rivalry is not the only reason the brothers become enemies. While Heinrich, a trained engineer, advocates for river regulation to prevent further dam breaches, Peter vehemently argues for reinforcing the dam. When old Doorn dies and Peter proves to be the sole heir, Heinrich leaves home.