While she is visiting her father and stepmother in California, 15-year-old Alison learns her mother is a lesbian.

That summer that Ali and her brother, Martin, left their mother in New York to visit their father in California brought joy and pain. For Ali, it was a time of impossible decisions, of breaking up and getting together, of loss and love. But when her father decided to keep her from returning to her mother, and her best friend couldn't stand to see her falling in love, Ali had to find a way to please everyone at once — and still be true to the woman she was becoming.