My mother knew a lot about spies and sometimes hinted that she had been one once. She knew a way, for example, to make an umbrella shoot a poison dart. Also that the CIA had tried to kill the president of Cuba with an exploding clam. She showed me how to send secret messages by underlining words in a newspaper and dropping it on a bench." To 8-year-old Grace Davitt, her mother is a puzzling yet wonderful mystery. This is a woman who has seen a sea serpent in the lake, who paints a timeline of the universe (in which "one billion years of real time = 24 days on the cosmic calendar") on the sewing-room wall, and who teaches her daughter a secret language which only they can speak. To the reader, however, it soon becomes clear that Anna Davitt is more than just eccentric. As her obsessions grow, her relationship with Grace's father, Robert, gradually deteriorates until at last the family breaks apart and Grace is left alone with her unstable mother. Writing an adult novel from a young child's point of view is a tricky business, but Jenny Offill pulls it off without breaking a sweat. God is in the details here, and these are spot-on, from young Grace's fascination with the blind girl who lives in the neighborhood to her speculations about the prior tenant of the uninhabited dog house in the backyard. Grace inhabits that peculiar geography of childhood where all things are reasonable, from the descriptions of gazelle-boys in her Encyclopedia of the Unexplaine