In 1935, six-year-old Emily Evans vanishes from her family’s vacation home on a remote Minnesota lake. Sixty years later, Emily’s sister, Lucy, lives in the lake house alone. Before her death, she writes the story of that devastating summer in a notebook that she leaves, along with the house, to her grandniece, Justine. Justine’s only neighbor is a strange old man who seems to know more about the summer of 1935 than he’s telling. Soon Justine’s troubled oldest daughter becomes obsessed with Emily’s disappearance, her mother arrives to steal her inheritance, and the man she left launches a dangerous plan to get her back.