This brilliant, boundary-leaping debut novel by Reif Larson turns 12-year-old genius map-maker T.S. Spivet's attempts to understand the ways of the world into a road novel l like no other. Festooned with diagrams, maps, drawings and rather remarkable marginalia, the book traces the journey of Spivet from his home on a Montana ranch to the halls of the Smithsonian Institution (he won an award). We found it helpful to note that Larsen thanks Lois Hetland, "my seventh grade teacher, for teaching me (almost) everything I know." His novel captures the exhilaration of adolescence.  (USA374, $16.00)