After making a disturbing discovery, a young woman begins a terrifying transformation in order to escape her father. Grounded in African-American folklore, Hag follows Moses as the anniversary of her mother's death approaches as Kenneth, her father, requests that she renew a dangerous covenant. Trapped by his rules and religion, Moses unconsciously reaches out to a spirit from the old world to protect her. It's in them that she hatches a plan to escape, but not without consequences. A nightmare plagued-Moses must choose between her current strained existence or trust in the old world and risk being tricked.