High school math teacher Iphigenia Julia Esker (who goes by her last name only) likes her world of fractals and Mandelbrot sets, the concrete answers arrived at by rules and logic. What she can’t handle is the messy complexity of the human heart. When she impulsively steps out of her self-created isolation to tutor an injured student and ends up falling in love with her pupil’s father, she has to remind herself of why it’s better to remain unattached. Esker is the kind of broken soul you root for, and Cohen’s wistful novel evokes the intense vulnerability of love and the shattering pain of loss. The heart may be a bully, but one is indeed the loneliest number.