Two lighthouse keepers try to maintain their sanity while living on a remote and mysterious New England island .In the late 1800s, retired timber-man Ephraim Winslow is sent on a boat to serve a contract job as a wickie for four weeks on an isolated island with a gassy elderly man named Thomas Wake. On the first day of the job, Winslow notices that there is a hole in his cot. As he digs into it, he finds a small wooden figurine of a mermaid and stuffs it in his jacket. Wake is perceived by Winslow as a strange and superstitious fellow, going up to the top of the lighthouse at night and stripping nude. Winslow decides to shrug it off, but is drawn towards the ocean. He sees floating tree stumps in the water along with a horrifying image of a mermaid in the deep.