When young mother Julia Albion arrives at Asylum Lake with her daughter during a late night storm hoping for sanctuary, she's a half step in front of a monstrous pursuer and racing into something far worse. Unable to gain entry into the house her grandmother willed to her, she and her daughter are forced to spend their night in the boathouse. Unknown to Julia, someone else has taken shelter there while his injuries mend and he lies beneath the floor hearing Julia's plight. The man in the boathouse is drawn to Julia and secretly watches her struggles while he searches for his own identity, often slipping into fevered dreams that reveal pieces of his own life, a history of Julia's house and a horrible danger that still lurks.