Prime numbers are the loneliest numbers. Sometimes primes can occur close together, but they are usually separated by a number in between (like 11 and 13). Young Mattia and Alice are lonely as well, both having suffered horrible incidents in their childhood that lead them to self-destructive behaviors. The two become friends as teens, but a certain closeness eludes them as they make choices that keep them apart as they grow older. Giordano’s haunting story of love and friendship is beautifully translated from the original Italian.