In the summer of 1935, six-year-old Emily Evans vanished from her family's vacation home on a remote Minnesota lake. The loss devastated the family. Sixty-four years later, Emily's sister Lucy writes the story of that harrowing summer in a notebook that she bequeaths, along with the lake house and a hefty investment portfolio, to her grandniece, Justine. For Justine, the lake house offers a chance to give her own daughters a stable home she never had, but the dilapidated house is cold in the winter, the lake silent and forbidding, and her only neighbors are two strange old men who seem to know more than they're telling about the summer of 1935. When Justine's troubled oldest daughter becomes obsessed with Emily's disappearance, Justine's mother arrives wanting money, and Justine's manipulative ex-boyfriend launches a plan to get her back, Justine must overcome her family's tragic legacy in her effort to save herself and her children.