After inventing the “bouncing bomb,” which can skip across water until it encounters a dam to explode, Dr. Barnes Wallis (Michael Redgrave) struggles for years to develop his new device for use in World War II. Once the bombs are ready to be tested, Wing Commander Guy Gibson’s (Richard Todd) squadron must be specially trained to drop the sensitive weapons on Germany’s Ruhr Dams. Based on true events, this British film features a legendary grand finale of special effects.