A prime number can be divided only by itself or by one it never truly fits with another. Alice and Mattia, both primes, are misfits who seem destined to be alone. Haunted by childhood tragedies that mark their lives, they cannot reach out to anyone else. When Alice and Mattia meet as teenagers, they recognize in each other a kindred, damaged spirit. But the mathematically gifted Mattia accepts a research position that takes him thousands of miles away, and the two are forced to separate. Then a chance occurrence reunites them and forces a lifetime of concealed emotion to the surface. Like Mark Haddons The Curious Incident of the Dog in the Night-Time, this is a stunning meditation on loneliness, love and the weight of childhood experience that is set to become a universal classic.