Childhood, often romanticized as a state of carefree and innocent play, is in truth lived according to an intricate set of rules: this stoop's third base; those sneakers are the best; don't ride your bike down that street or you'll lose it to a bully. In his new novel, The Fortress of Solitude (Doubleday), Jonathan Lethem meticulously maps out an eight-block square of 1970s Brooklyn whose arcane folkways are navigated and absorbed by young Dylan Ebdus. Dylan, the only white kid on his block of Boerum Hill (or Gowanus, as his idealistic hippie mother calls it, rejecting the nomenclature of gentrification), and his best friend, Mingus Rude, exist for a time in a magical realm of dilapidated row houses, cracked slate sidewalks, and ailanthus trees, where bums fly through the sky like comic book heroes and supervillains live just around the corner. But though the book takes its title from Superman's arctic hideout, the fortresses of solitude Lethem constructs for his characters aren't places they can go to get away from it all. As the novel moves from the 70s through the 90s, from the smooth rhythms of doo-wop, soul, and Motown to the aggression of rap and punk, he renders in faithful, bittersweet detail the ways the codes of childhood evolve into the alienating rituals of adulthood. Lethem reads at 7:30 PM on Thursday, October 9, at Barbara's Bookstore, 1100 Lake in Oak Park, 708-848-9140.