Odette Hallowes reached British intelligence by mailing her vacation photos to the wrong office. In 1942 the Admiralty asked the public for prewar snapshots of the French coastline, and she sent hers of Boulogne to the War Office instead, where they landed on the desk of Maurice Buckmaster, head of the Special Operations Executive. Her assessors called her excitable, temperamental, stubborn, and short on worldly experience, and pushed her through anyway. What they were reading as flaws had been built decades earlier: as a girl in Amiens she spent more than three and a half years completely blind, then months bedridden with polio. Her convent teachers called her a difficult child. She was learning how to live in the dark and how to survive a body that would not cooperate.

A training injury kept her from parachuting, so she was smuggled into  ...