Julia, David, and Erika grew up together, spending summers at their idyllic Vermont lake homes. Now adults - with their own sullen teens, endless mortgages, and low-voltage sex lives - the three friends have amassed secrets over the years. This summer, David is eager to show off his newly renovated home and his much-younger girlfriend. When she mysteriously vanishes after a shouting match, Julia and Erika wonder just how well they know their friend. As a search is mounted, an intricate web of lies, deceits, and betrayals spanning generations starts to surface, and everyone finds themselves in danger of becoming the next victim. Of the lake, or something darker.