1946, Manhattan. One morning while passing through Grand Central Terminal on her way to work, 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. In a moment of impulse, Grace takes the photographs and quickly leaves the station. A remarkable story of friendship and courage centered around three women and a ring of female secret agents during World War II.