SOE agents are sent on a mission to destroy a V1 flying bomb facility, situated in an underground bunker un Northern France. Ordinary people are recruited and subjected to highly demanding training in the seclusion of a large house in the country. They are each given a code name comprising the French word for a different type of bird, such as 'Hibou' and 'Chardonneret'. They train for a parachute jump, and perform a trial operation in a real French village. Can their extraordinary training give such ordinary people a real chance to succeed?
