By way of Katya, a novelist and fortyish mother of two, Vapnyar delivers “a very dark comedy,” one charting Katya’s complicated love life, her adjustment to Brooklyn after a childhood in the USSR, and her struggle to become a fiction writer. The heart of the story, however, is Katya’s relationship with her “hero of heroes”—her mother.  A widow and mathematician, Katya’s mother wrote textbooks for children before she immigrated, and late in life she decides to produce one for adults. But she dies of cancer before she’s done more than assemble twenty “flash cards” with theories and formulas. Katya, torn up by grief and facing the end of her marriage, uses these cards to structure the “self-help math book” that becomes the story of her own life. And she knows her life could use some structure. Married to a man she no longer loves, pining after the man she’s loved since she was seventeen, and trying to be swept off her feet by a Putin-era “Russian Gatsby,” Katya feels she lives an Escher life in an Escher house: the parts look normal, but won’t work together. If her search for a rational basis for emotions doesn’t make her “immune to the craziness of love,” it introduces readers to a character as delightful and unpredictable as she is passionate and smart.