Bestseller Hoag (_Kill the Messenger_) ventures into serial killer territory with results sure to please her many fans, though unresolved plot threads, both intentional and inadvertent, may put off veteran readers of the genre. One fall day in 1985 in Oak Knoll, Calif., fifth-grader Tommy Crane and his sidekick, Wendy Morgan, are fleeing the class bully, Dennis Farman, through a local park when Tommy stumbles over the head of a dead woman buried up to her neck. Two hours from Los Angeles, Oak Knoll is not the sort of town where major crime is a problem, but a serial killer is on the loose who's already murdered and tortured several women and has another on deck in his secret lair. Fifth-grade teacher Anne Navarre, who counsels Tommy and Wendy, is soon at the center of the...