One morning while passing through Grand Central Terminal, Grace Healey finds an abandoned suitcase tucked beneath a bench. Unable to resist her own curiosity, Grace opens the suitcase, where she discovers a dozen photographs --- each of a different woman. She soon learns that the suitcase belonged to Eleanor Trigg, leader of a network of female secret agents who were deployed out of London during the war. Twelve of these women were sent to Occupied Europe as couriers and radio operators to aid the resistance, but they never returned home. Setting out to learn the truth behind these women, Grace finds herself drawn to a young mother turned agent whose daring mission overseas reveals a remarkable story of friendship, valor and betrayal.