Based on Ann Brashares' best-selling novel about a special 16th summer in the lives of four lifelong friends. The film stars Alexis Bledel, Amber Tamblyn, America Ferrara and Blake Lively as four 16-year-old best friends who are separated for the first time. On a last shopping trip together, the girls find a pair of thrift-shop jeans that fits each of them perfectly and they decide to use these "magic" pants as a way of keeping in touch over the months ahead, each girl wearing the jeans for a week to see what luck they bring her before sending them on to the next. Though miles apart, the four friends still experience life, love and loss together in a summer they'll never forget.