Paul VanDerMere is vacationing at a lakeside cabin in the woods with his dad and stepbrother, Jasper. When he and Jasper return from a canoe trip to one of the small, uninhabited islands on the lake, Paul happens to glance back and see a young girl staring back at him. He's soon drawn in to the unsettling mystery of a strange girl who randomly appears and disappears from the island. When he hears a local ghost story about a young girl just like her, he begins to wonder if he's dealing with a real person... or something entirely different.