"Pyewacket" follows the story of Leah, a teenage girl who is forced to move to a house in the woods by her unstable mother after the painful passing of her father. Feeling trapped and hopeless, Leah turns to Black Magic to release her anger. She naively performs an occult ritual found in a book on her bedroom shelf to evoke the spirit of a witch to kill her mother.

Stricken by guilt, Leah desperately tries to reverse the spell, but soon realizes she has awoken something in the woods, and nothing can prepare Leah for the terror she has unleashed.