Enemies of the Heart by Rebecca Dean
June 1909, in a large Berlin mansion, cousins Zelda and Vicky are about to meet brothers Berthold and Josef for the first time - an evening that will alter the course of their lives forever...
Vicky Hudson is only seventeen when she marries Berthold and moves from her idyllic Yorkshire home to Berlin. She finds it hard to adjust to her new life, not least when she discovers that the family business she has just married into - Remer Steel - is producing weaponry for the German army. With the First World War looming, Vicky flees to Yorkshire with her children, leaving Berlin, and her husband, behind.
Striking dark-haired beauty Zelda Wallace is no stranger to marriage. Widowed at just twenty-one with a young son, she is eager to meld into Berlin's high society and sever all ties with her American identity in order to become a true Berliner. But beneath her exotic looks, Zelda holds a deeply hidden secret that if revealed, could threaten everything she holds dear...