The story centers around a mathematician, "the Professor," who suffered brain damage in a traffic accident in 1975 and since then can produce only 80 minutes' worth of memories, and his interactions with a housekeeper (the narrator) and her son "Root" as the Professor shares the beauty of equations with them. The novel's bibliography lists the book "The Man Who Loved Only Numbers", a biography of the mathematician Paul Erdős. It has been said that Erdős was used as a model for the Professor.