Annabelle Murphy has spent the last two years recovering from the death of her husband, Knox, who lost his life while flying alone in his plane on his way to go hunting…or so she believes. As she grieves and tries to balance her longing for him with her present life, her friends in South Carolina's Low Country surround her with love. In particular, Knox's best friend, Shawn, has stepped in to comfort Annabelle. Her life still has a "Knox-shaped emptiness," but she also has her children --- 16-year-old Keeley and college student Jake --- and her job as an advice columnist.

She is just recovering some of her equilibrium after the tragedy when the town sheriff arrives with startling news. They have finally found Knox's plane, which had gone down in the Colorado wilderness, and his body is there. Although Annabelle has known that Knox surely died, the finality horrifies her. But she is stunned when the sheriff reveals that her husband was not alone when he perished. A woman's corpse was also discovered inside his plane!

Annabelle is humiliated, dazed, and hurt beyond words. She has no idea who would have accompanied Knox on his hunting trip. Or was he even actually going hunting? Had his solitary hunting trips been a cover-up for an affair all those years? Suddenly, she has doubts about the most basic cornerstone of her life --- her loving, solid marriage. None of her and Knox's friends can explain the mysterious lady, and everyone is shocked and disbelieving that Knox would stray.

The story is about to hit the newspaper. Annabelle must tell her children the cruel news, which leads them to question who their father really was. Annabelle finds herself unable to decide if she should continue to have faith in her memory of her loving husband, in the face of what seems to be irrefutable evidence that he strayed.

Meanwhile, a young woman named Sofie Milstead in Newboro, North Carolina, studies dolphins at a research center. In spite of her relationship with her much older boyfriend, the dolphins are her one true love. The endearing mammals offer Sofie peace in a life filled with sorrow, lies and secrets. She has been so indoctrinated with the need to keep the real facts about her life hidden that she herself sometimes has problems discerning between the truth and the fiction of her past.

An art historian named Michael Harley begins hounding Sofie for answers about an artist he believes may be connected to Sofie's mother through her art studio. This is upsetting to Sofie, but not nearly so much as encountering a person from her past --- someone who expects Sofie to share her memories of Knox Murphy. How can she talk about him without telling of those forbidden truths? It's impossible.

In a lyrical voice, Patti Callahan Henry seamlessly weaves an intriguing mystery from the separate strands of Annabelle and Sofie's lives, while invoking the wonder of their seaside surroundings. Each character is multilayered, with believable emotions that arise as long-hidden secrets come to light. Riveting to the end, the plot twists and turns, giving us a complex enigma to puzzle over, along with a poignant exploration of the very nature of faith and love.