Mimi Brotherton—orphan and sister of a mathematical genius—is used to defining herself according to others. Bound together by the tragic deaths of their parents, she and her older brother, Art, share the family home and have a strong, if unequal, relationship—one in which Mimi is there whenever Art needs her, supporting his academic peaks and talking him out of his emotional valleys. When she decides that she’d like to get out in the world and maybe even find a boyfriend, Art is cautiously supportive, as long as his sister is searching for love using the methods he’s laid out for her. But when Mimi meets Frank, another mathematician, Art is instantly suspicious. Does Frank truly not have his sister’s best interests at heart, or is Art’s concern due to the terrifying possibility of an independent life for Mimi?