At the beginning of the 1960s, NATO sends a German envoy (Helmut Schreiber) to the British village of Rocksmouth to salvage an old shipwreck so that a new naval base can be established there. Two decades before, in 1942, the Princess of India was supposed to bring children to safety in Canada but was sunk by a German submarine at departure, killing 58 people, most of them children.
Diver Bill Smith (Eberhard Esche) is one of the survivors of the catastrophe. Although his fiancée Bessy wants to leave this dark chapter behind them, Bill starts to investigate. He finds out that the German envoy is Eberhard Wedel, the captain of the submarine that torpedoed the Princess of India. When Wedel is found dead in the lake, suspicion naturally falls on Bill...