Allie has unexpectedly taken leave from her job as an academic research scientist to fly to a place she only recently heard about in a letter. She's flying to Italy to unpick the truth about what her mother did all those years ago. Beside her is her best friend since schooldays, Ed. He has just shocked everyone with a sudden separation from his wife, Julia. Allie hopes that a break will help him open up. But the secrets that emerge as the sun beats down on Lake Garda and Liguria don't merely concern her family's tangled past. And the two friends are forced to confront questions about their own life-long relationship that are impossible to resolve.