In the 1890s, Ephraim Winslow begins a four-week stint as a "wickie" (
lighthouse keeper) on an isolated island off the coast of New England, under the supervision of former sailor Thomas Wake. In his quarters, Winslow discovers a small
scrimshaw of a
mermaid and keeps it in his jacket. Wake immediately proves to be very demanding, subjecting Winslow to taxing jobs such as emptying
chamber pots, maintaining the machinery, carrying heavy
kerosene tanks up the stairs, and painting the lighthouse, while barring Winslow from the lantern room. Winslow observes that, every night after ascending the lighthouse, Wake disrobes before the light. During his stay on the island, Winslow begins to hallucinate
sea monsters and logs floating in the sea, and
masturbates to the mermaid on the scrimshaw. Winslow is bothered by a one-eyed
gull, but Wake warns him against killing it under the
superstitious belief that gulls are reincarnated sailors. One evening while dining, Wake reveals to Winslow that his previous wickie died after losing his sanity, while Winslow reveals that he is a former
timberman from
Maine who was stationed in
Canada and is now seeking a new trade. The day before the scheduled departure, Winslow discovers a dead gull inside the
cistern, bloodying the drinking water. He is attacked by the one-eyed gull and brutally bludgeons it to death. The wind drastically changes direction and a fierce storm hits the island. Winslow and Wake spend the night getting drunk, and the storm prevents the
lighthouse tender from collecting them the next day. As Winslow empties the chamber pots, he discovers the beached body of a mermaid, which waves and howls at him. He flees back to the cottage, where Wake informs him the storm has spoiled their rations. Winslow is not worried because he thinks the tender is only a day late, but Wake says that they have already been stranded for weeks. The pair unearths a crate at the lighthouse's base that Winslow assumes contains reserve rations, but it is full of bottles of alcohol. As the storm continues to rage, Winslow and Wake get drunk every night and alternate between moments of intimacy and hostility. One night, Winslow tries unsuccessfully to steal the lantern room keys from Wake and contemplates murdering him. Winslow later sees the one-eyed head of Wake's previous wickie in a
lobster trap. While drunk, Winslow confesses to Wake that his real name is Thomas Howard, and he assumed the identity of Ephraim Winslow, his cruel foreman in Canada whom he deliberately allowed to drown during a
log drive. Howard has a menacing vision of Wake accusing Howard of "spilling [his] beans" and runs to the
dory to try to leave the island, but Wake appears and destroys the boat with an axe. After chasing Howard back to their lodgings, Wake claims it was Howard who chased him and hacked up the dory, as Howard was driven mad by his confession. With no alcohol left, Howard and Wake begin drinking a concoction of
turpentine and honey, and that night a giant wave crashes through the wall of their cottage. In the morning, Howard finds Wake's logbook, in which Wake has criticized him as a drunken and incompetent employee and recommended he be fired without pay. The two men argue, and Howard attacks Wake while hallucinating the mermaid, the real Winslow, and Wake as a
Proteus-like figure. Howard beats Wake into submission and takes him to the hole at the base of the lighthouse to
bury him alive. Before losing consciousness, Wake describes a "
Promethean" punishment that awaits those who look in the lantern, and Howard takes the keys to the lantern room. Howard goes to get a cigarette, and Wake returns and strikes him with the axe. Howard disarms and kills Wake before ascending the lighthouse. In the lantern room, the
Fresnel lens opens to Howard, who reaches in and violently screams in distortion before falling down the lighthouse steps. Some time later, a barely-alive Howard lies nude on the rocks with a damaged eye as a flock of gulls peck at his exposed organs; the lighthouse is nowhere in sight. ==Cast==