Life in bustling New York did not make Ada Santorini happy. Her success at work is overshadowed by a personal tragedy: two years ago, she lost her lover and daughter. Escaping from difficult everyday life, Ada decides to settle in a houseboat on Lake Union in Seattle. There, she suddenly stumbles upon a mysterious chest that hides ancient secrets. Half a century ago, in this very place, young Penny Wentworth experienced great love and suddenly disappeared. Ada solves the mystery of her disappearance with the help of Alex, a photographer who lives in a nearby house. Gradually, the woman learns a story that is strangely intertwined with her own. Will Ada have the courage to love again?