Regular print edition published: New York : Ballantine Books, [2016].

Includes bibliographical references (pages 691-704)

Manhattan, 1939. New York socialite Caroline Ferriday's biggest problem is resisting the advances of a married actor. Across the Atlantic, Kasia Kuzmerick, a Polish Catholic teenager, is affected when Germany declares war on Poland. As tensions rise, Caroline's interest in aiding the war effort in France grows; she hears about the dire situation at the Ravensbruck all-female concentration camp. Kasia's carefree youth is replaced by a fervor for the Polish resistance movement. Through Ravensbruck - and the horrific atrocities taking place there told in part by an infamous German surgeon, Herta Oberheuser - the two women's lives converge in unprecedented ways.