It's been a year since Billie Flanagan--a Berkeley mom with an enviable life--went on a solo hike in Desolation Wilderness and vanished from the trail. Her body was never found, just a shattered cellphone and a solitary hiking boot. Her husband and teenage daughter have been coping with Billie's death the best they can: Jonathan drinks as he works on a loving memoir about his marria; Olive grows remote, from both her father and her friends at the all-girls school she attends. But then Olive starts having strange visions of her mother, still alive. Jonathan worries about Olive's emotional stability, until he starts unearthing secrets from Billie's past that bring into question everything he thought he understood about his wife. Who was the woman he knew as Billie Flanagan? Together, Olive and Jonathan embark on a quest for the truth--about Billie, but also about themselves, learning, in the process, about all the ways that love can distort what we choose to see.