Forgive the incendiary title of Rape: A Love Story; Joyce Carol Oates can't help herself. Twelve-year-old Bethie Maguire loves policeman John Dromoor. He's the first cop on scene after Bethie's mother is gang-raped in a boathouse, as Bethie listens, trapped in a hiding place behind canoes. Maybe Dromoor can make things safe again. Oates tells her tale in second and third person, flowing through Bethie's panic, Dromoor's cool anger, the cramped malice of the rapists. Her frank, calm writing has a dazing effect, which makes the narrative bumps even more disquieting: ''It's a game.... They let your mother break free, run barefoot and stumbling in the grass, then catch her. Three of them like drunken dancers.'' Vintage Oates, ''Rape'' is disturbing, stunning, and bitter-bittersweet.