THE 39 CLUES, BOOK I

“Synergy” is the name of the game in Scholastic’s post-Potter search for market share. Grace Cahill has died, and her orphaned grandchildren Amy, 14, and Dan, 11, are among the heirs offered a choice: They can accept one million and walk, or they can take the first clue in a worldwide scavenger hunt to find the secret that has made the extended Cahill family the most powerful family in world history. Every other heir is out to get Amy and Dan, Grace’s supposed favorites, as they work their way through the puzzles in this first volume of a ten-book “multi-platform” series. Six trading cards come with each trade-edition copy, and more can be purchased separately. Cards can be entered on an accompanying website, where readers six to 14 can “enter the race” by playing mystery games. Each new volume, by such authors as Gordon Korman and Peter Lerangis, spawns a new contest with real cash prizes. Librarians should be careful to purchase card-free library editions to avoid circulation headaches. (Novelty/fiction. 9-14)