In Great Britain, the term "crime fiction" refers to everything from a cozy mystery to a police procedural. Here in the U.S., we divide our crime fiction into separate genres, according to librarian Nancy Pearl. A mystery starts with the world out of kilter, and ends with everything put to rights again. A police procedural focuses on the nuts and bolts of solving crimes. And a thriller? Well, as Nancy Pearl told KUOW's Marcie Sillman, a thriller is a page turner, as addictive as potato chips.