A sister and brother seek revenge against an evil force that has haunted them since childhood.

Looking for some peace and quiet, Tom rents out a small and isolated lakehouse, one marked by a local legend of a woman who, after drowning, haunts the surrounding woods and drowns anyone she encounters. That myth particularly intrigues Tom’s new neighbor, Al, who’s mourning the recent death of his husband. Starting off rather friendly, Tom and Al’s rapport slowly changes as the former befriends a mysterious woman named Nina, for whom Al can’t shake his negative suspicions.

Suspecting that people around him are turning into evil creatures, a troubled man questions whether to protect his only friend from an impending war, or from himself.