As usual M. M. Kaye uses a backdrop with which she is familiar--post WWII Berlin and the British military culture. She traveled with her husband who was in the British army. The bombed out buildings, inconveniences, and the family members' interactions give depth to the plot. The main characters are well-drawn and add to the suspense, which resolves into a complete surprise at the end, since the killer's interpretation of events is so completely different from the heroine's viewpoint. The strong, romantic hero, of course, saves the day.