Sidney Newlin is an intense young boy whose eccentric, wistful imagination constantly reinvents the unpredictable world around him and tries to transform it into something less threatening and chaotic. His one constant nemesis is his older sister, Maddie, who teases and belittles him relentlessly.

Sidney's heroic versions of himself ― as a spaceman, a cowboy, a star baseball player on the Chicago White Sox― are tested by the realities he encounters on his adventures in his suburban community in Northwest Indiana. Along the way, he discovers the fleeting nature of childhood: the treachery of old toys, the shifting hierarchy of his social status, the early roots of rock n' roll, the loyalty of true friends, and a growing sense of injustice in this coming-of-age novel set in the early 1950s.