After her father is murdered, fifteen-year-old Ingrid Lang flees her home in Austria only to become separated from her siblings and stranded in the Dutch city of Arnhem with a pair of broken legs. Her future would be bleak if not for the kindness of a local doctor and his daughter Anita van der Veen. But before Ingrid can finish her healing and continue her journey to find her brother and sister, the forces of Nazi Germany overrun the Netherlands, leaving her trapped in an enemy occupation.

Four years later, Gerrit Hendriks, wanted by the Gestapo for his work with the underground, flees to his grandfather's home in Arnhem, where he finds Ingrid and the van der Veens deeply ensconced in the local resistance. But suspicion, prejudice, and conflicting beliefs soon leave Ingrid and Gerrit at odds with each other.

As Ingrid and Gerrit gather intelligence for the Allies, smuggle airmen and other refugees to safety, and plan acts of defiance against the Nazis, irritations soften and teamwork blossoms. They soon realize that if they want to have any hope of outsmarting a German intelligence officer with a tie to Ingrid's past, they'll have to work together. As the two begin to recognize just how much they mean to each other, they find themselves in the middle of an enormous airborne operation, and the battles that follow will change everything—for Ingrid, for Gerrit, and for the Netherlands.