The bulk of this film takes place as a flash back within a flashback. The elderly nursing homebound narrator tells us from the time when she was a anthropology academic exploring snake lore in Oklahoma. Her investigations let her to a insane asylum in Guthrie. There Dr. McNeill told her some of the legend of Yig and its terrible curse . He told he had some proof of the curse in the basement of
the madhouse and would tell her the story after he showing it to her. He leads her down to a isolated cell where he pulls back the shutter to reveal the patient, a reptilian looking humanoid with mottled skin and a slit like nose. He tells her the creature doesn't age and relates to her the tale of its origin:
The story then starts its second flashback and we see Walker Davis and his wife Audrey, 2 typical farmers who have left Arkansas to set up a new farmstead in the newly opened public lands. Well, they were typical all ways except for Walkers unnatural fear of snakes. While making camp, the couple try to avoid typical areas where these serpents are found. During their travels they meet a man who first introduces them with his tales to the Snake Gog Yig who protects its child, the snakes. This does little to improve Davis' ophidiophobia. During some bad weather they are forced to make shelter among some sheltered rocky area and there Audrey stumbles upon a nest of rattle snakes. Much to Walkers horror, she kills them which in her husband's mind with invoke the wrath of Yig.
Eventually they reach their destination where they build a simple cabin and set to farming. After the first harvest, they have a party at Halloween to celebrate - however this is the time when Yig is most dangerous according to legend. After the singing and dancing finishes and their neighbours leave the couple retire. During the night, Audrey is woken by a terrible dream about the Snake God. She then hears a noise in the room and Walker lights a lamp and investigates. The illumination reveals the cabin floor in cover in rattle snakes. Walker collapses and the light goes out. Audrey is terrified and filled with panic. From the shadows a humanoid figure lurches towards her. Fearing that this is Yig looking for revenge, she grabs an axe that was beside the bed and strikes the humanoid over and over.
