New York socialite Caroline Ferriday has her hands full with her post at the French consulate and a new love on the horizon. An ocean away from Caroline, Kasia Kuzmerick, a Polish teenager, senses her carefree youth disappearing as she is drawn deeper into her role as courier for the underground resistance movement, where one false move can have dire consequences.
For the ambitious young German doctor, Herta Oberheuser, an ad for a government medical position seems her ticket out of a desolate life. Once hired, though, she finds herself trapped in a male-dominated realm of Nazi secrets and power.
The lives of these three women are set on a collision course when the unthinkable happens and Kasia is sent to Ravensbrück, the notorious Nazi concentration camp for women. Their stories cross continents — from New York to Paris, Germany, and Poland — as Caroline and Kasia strive to bring justice to those whom history has forgotten.