Caught up in the drama of World War I, a German nurse and a Swiss doctor fall in love and together experience the horrors of war. They marry, and years later move to Philadelphia to raise two children in the Roaring Twenties and Depression years of the 1930s. Their Swiss-born daughter, an artist, knows she wants to teach at the Sorbonne and focuses on accomplishing that goal. What she didn't focus on, however, is falling in love. Young and independent, she tries to ignore the drumbeat of yet another war, which will change her life forever. Their second child, a brilliant and determined male, collects university degrees on his way to medical school; however, a latent dream to be a pilot exposes exceptional skills in aircraft mechanics. This, in turn, provides a pretense by which he avoids conflict with his parents while earning his pilot license. When he volunteers to fly with the American Eagle Squadron, he not only fights for his life in the Battle of Britain but also loses his heart to a woman in the ATA (Air Transport Auxiliary). The small family's adventures are interwoven with that of a family friend, a German cryptologist, from WWI. The intrigue intensifies since he now is working on the Enigma Project in WWII, and his personal challenge is to smuggle his Jewish father and uncle, as well as precious jewels, out of Nazi Germany. Twists and turns present unsteady footing for those finding themselves tripping over moonlight.