The structure was effective in building suspense, as was Flynn's technique of dropping little clues or maybe-clues. "Oh! A men's dress shoe! Oh! A possible motive!" And the setting was done well, capturing both the good and the bad of a close-knit community and providing a realistic view of the geography of Kansas (it's not just "flat," you know). 
 But the ending left me unsatisfied. Libby seems to change too much too fast, Lyle doesn't seem like a real person, and I never could figure out what the heck Ben's motive was for anything. Maybe I've just read too many of Flynn's novels, but the inept and/or evil women are really kind of getting to me. At least this one has Aunt Diane.