Jack Watson has never heard of Sherlock Holmes until a new girl moves in next door; her name is Saturday Holmes; and since she has a ``nose'' for solving mysteries, she loves practicing her skills as a detective. Becoming (inevitably) this Holmes's sidekick, young Watson helps her solve three mysteries concerning some missing teddy bears and neighborhood ghosts. In his first book for younger readers, Taylor—who writes adult mysteries- -imbues both his characters and his writing style with a quaint, rather old-fashioned charm that is nicely extended in Schongut's appealing pen drawings—which reveal that this is an interracial friendship. Accessible language and the story format make this an equally good choice for reading aloud or for encouraging reluctant readers. (Fiction. 7-9)