The post-war summer of 1945: The British occupation army has set up its central administration on the island of Nordstrand. Medical assistant Gesa works in a laundry. Her lover Friedrich, a former Wehrmacht officer, is imprisoned as a prisoner of war on the mainland. The two are separated by barbed wire and the cold North Sea. Only by Friedrich risking his life and swimming over to the island at night can the two of them see each other. Nevertheless they repeatedly dare to meet in the high grass of the dunes. But then Gesa falls in love with Captain Simon, a British officer with German roots. The night in which Gesa admits her love for Simon to Friedrich, however, they become involved in a fateful occurence: the murder of an English soldier. Friedrich is suspected of the murder and threatens to face the death penalty. Simon is assigned the case. Of course, he has no idea that the defendant is Gesa's former lover.