Donna Leon has said that there is one main reason people turn to detective fiction: It's a great pleasure to see someone smart trying to solve a problem. If you read about a detective, you're simply reading about someone going to work, day after day, until a particular project is completed. Detective stories are conservative stories: You know that there will be a solution, and you know justice, or something like justice, will triumph in the end. (This is a nice break from actual life, where solutions are scarce, and so many issues involve a murky compromise.) Jane Harper's "Exiles," one of the standout crime novels of 2023, features a decent guy, Falk, with a problem. Someone he knows--a mom--has gone missing. She attended a local fair, in Australia, left her infant in a carriage, and disappeared. Why on Earth? Falk is driven to find a solution because he knows the missing woman's teenaged daughter; this kid is suffering, and she can't imagine that her mo...