There is something about a mystery set during wartime that feels immediately, almost urgently readable. The best WWII historical mystery novels understand this instinctively, they give you the war and the puzzle in equal measure, so that you're turning pages both to find out who did it and to find out whether anyone survives the week. If you've ever finished a Christie novel and wished the stakes felt a little higher, or put down a WWII history and wished someone would just explain what was...