In May 1944 Louise Desfontaines (Sophie Marceau), a member of the French Resistance, flees to Spain after her husband is killed, where she is captured and later expatriated to London. She is recruited by the Special Operations Executive (SOE), the secret spy and sabotage service initiated by Winston Churchill. Louise is given an urgent first mission: to extricate a British agent (Conrad Cecil) who has fallen into German hands while preparing the invasion of Normandy. The agent has not yet revealed anything but time is pressing.