In Trapeze, a young woman is recruited by the British to act as a spy in France during World War II. After a long build-up - during which she undergoes spy training, has a love affair, and begins to worry about the bomb - she finally parachutes into German occupied France and begins her missions. This part of the novel, where the protagonist is operating in France, is quite suspenseful. And the ending of the book was quite a surprise.
Much like I imagine the times themselves were, Trapeze is dark and tense. It is an interesting novel.