When Angela Ellis returns to her childhood home on St. Nabor Island, South Carolina, her junior year of college interrupted indefinitely by her mother's death, she doesn't know how she'll ever be able to function in the world without her mother's love, support, and guidance. Soon after her mother's funeral, strange sounds begin to trouble her in the night, sounds she swears are her mother's angry voice. In an effort to find peace for herself and for her mother's restless spirit, Angela begins a ghost hunt that makes her friends fear for her sanity and that leads her to more questions than answers. Her parents, it turns out, were extraordinary secret keepers, and now Angela is on her own to discover the truth.

One thousand miles away on Devil's Back Island, Casey Seaver has built a sweet life for herself hidden away from the rest of the world in Maine's Casco Bay. She runs a small café and keeps to herself, rarely visiting the mainland. When a posthumous letter arrives from her estranged mother, old memories and new problems interrupt her island idyll. For 20 years she has been trying to forget the mistakes and injustices of her youth, and she has nearly convinced herself she has succeeded, but her mother's words shatter that illusion. As she tries ignore her mother's dying wishes, a stranger arrives on the island, looking to bring Devil's Back into the 21st century at last. If he has his way, Casey's island haven will be a refuge no more.

As plans for a new resort on Devil's Back spur Casey to move her life forward, Angela's ghost investigation forces her to examine the past. Fate has put their lives on a collision course, and through each other, they will find the way through their grief.