Acts of cruelty and bigotry and a shocking betrayal propel this colorful if overstuffed historical novel by Zimler (The Last Kabbalist of Lisbon), set in 18th- and 19th-century Portugal. John Zarco Stewart is the son of a Scotsman and, through his mother, is descended from converted Jews called Marranos who have kept their identity a secret since the Spanish Inquisition. John grows up in the city of Porto unaware of his true heritage until a necromancer curses him when he is nine. In the same year, his best friend drowns before his eyes, and he is only comforted when his father returns from a trip to Africa with a Bushman called Midnight, a healer and freed slave who teaches John many things as he grows into manhood. But Midnight, too, meets a violent end, and when John is 16, Napoleon's armies invade Portugal and John's father is killed defending Porto. Years after the war, John discovers that his father, who he believed was a hero, had committed an unthinkable act of treachery. In attempting to atone for his father's misdeed, John travels from Portugal to England then antebellum America. Zimler packs his tale with exotic detail, describing Porto's bird markets, plantation life in South Carolina and the lives of Jews in hiding. Though his prose style is somewhat stiff as he attempts to echo 1800s speech patterns (" 'Close your goddamned snout and run, you little mole!' ") and many of the events in the story are melodramatic, the narrative has a vintage flavor that becomes absorbing. (July 1)