A prime number is a solitary thing: it can only be divided by itself, or by one; it never truly fits with another. Alice and Mattia are also alone with their personal tragedies.
As a child Alice"s overbearing father drove her first to a skiing accident, and then to anorexia. When she meets Mattia she recognizes a kindred spirit, and Mattia reveals to Alice his terrible secret: that as a boy he abandoned his mentally-disabled twin sister in a park to go to a party, and when he returned, she was nowhere to be found.
As they grow into adulthood their destinies seem irrevocably intertwined. But then a chance sighting of a woman who could be Mattia"s sister forces a lifetime of secret emotion to the surface. Это и многое другое вы найдете в книге The Solitude of Prime Numbers (Paolo Giordano)