The Czar's Spy: The Mystery of a Silent Love

Strange is a good way to sum up the story. The refusal of our hero to get more help is, frankly, quite confusing, and he's darn lucky to survive. The ending is bad - you just let the villain go? Really? Yeah, he gets his just desserts, but still, not a fan of that sort of conclusion by accident. Regardless, I do love the idea of falling love by photograph. If you like a strange, complicated mystery, give it a try.