Enemy in My Arms — Ashland Price

World War II. Young Renate Rosen, a pretty Jew, works for the underground in Berlin. Under the assumed identity of Kristina Mechler, an Aryan who had recently died, she travels to Munich to deliver a message to her sister and brother-in-law, and then escape to Switzerland. But troubles ensue. Katie and David are captured by the Gestapo and Renate escapes by pretending again to be Kristina, a ruse fraught with danger as she discovers surprises from her character's past. One of those surprises is SS colonel Hans Kauffmann, who falls in love with her and may be her only protection against exposure and certain death. But can she let herself love him?