Something is obviously not-as-it-should-be around the handsome, blooming Sunberg household in San Sebastian, California. Used-car biggie Papa Sam always smiles; Mama Sunberg is a bosomy recluse given to exposing herself to passers-by; first son Gus drinks; second son Luke is half-witted; big daughter Thelma is a frigid tease prone to hysterical laughing fits; baby Gunnar is retarded; housekeeper Hannah is a beady-eyed harpie. Only teenager Kristin seems outgoing and normal, but she's plenty worried--especially when private detective Alan Bonner comes to town, determined to find out what happened to Tony Lopez, a Sunberg employee who came to dinner one night and promptly disappeared. This potent set-up, with an initial, foreshadowy mood of sunnyoutside/secrets-inside, is deftly assembled, but author Williams doesn't know how to kill time or build suspense till she's ready to reveal the supernatural truth; the bulk of the book is talky tedium in the detective-story mold as Bonnet questions, questions, questions (aided by sleep-in sidekick Kristin). Then there's a final phase of violent doings and long-winded explanations involving Papa's impotence, Mama's frigidity, Hannah's erotic potions, childbirths without labor, incest, murder, suicide, and resurrection. Williams (The Messenger) continues to show a talent for atmospherics, but defective structure is a fatal flaw when it comes to Rosemary's Babies, and this is one of Rosemary's hopelessly misshapen offspring.