In this sequel to Daniel Kirk's Library Mouse-a Parenting magazine Book of the Year-Sam falls asleep in the library and awakens just in time to scamper out of sight. In his haste, he leaves behind his mouse-sized notebook. As a boy named Tom puzzles over the mystery of such a small book, he discovers Sam's mouse hole. Soon Sam and Tom form an unusual partnership that would surprise others-if they only knew. "A sure-fire hit . This is fun, fun, fun."-Booklist, starred review