``Chase,'' a brown mouse, explores Maine's Margaret Chase Smith School while McMillan snaps a dozen familiar objects and places from the pet's closeup point of view; then, overleaf, he backs off to show the appealing little creature investigating the same, now-captioned, setting. The guessing game that results— it's not always easy to identify objects like a worn end of chalk, a stack of trays, or piano keys in closeup—is just one of several features here. The mouse tours the whole school (classrooms, gym, library, etc.), implicitly outlining a day's activities; there's also an outside photo of the school and a ``map'': a floorplan with the mouse's route. In addition, McMillan's vibrant, beautifully composed color photos are an inspiring demonstration of the intriguing patterns that can be found in everyday things. Note on production and participants. (Nonfiction/Picture book. 4-8)