Undine works as a historian lecturing on Berlin's urban development. But when the man she loves leaves her, the ancient myth catches up with her. Undine has to kill the man who betrays her and return to the water.

When a proposed pipeline creates hostilities between residents of a small town, a newly-arrived forest ranger must keep the peace after a snowstorm confines the townspeople to an old lodge. But when a mysterious creature begins terrorizing the group, their worst tendencies and prejudices rise to the surface, and it is up to the ranger to keep the residents alive, both from each other and the monster which plagues them.