In the 17th century, a man named William is excommunicated from a Puritan Christian plantation in New England alongside his family — wife Katherine, daughter Thomasin, son Caleb, and fraternal twins Mercy and Jonas — due to the crime of "prideful conceit". Exiled, the family builds a farm by a large forest. After several months, Katherine gives birth to her fifth child, Samuel. One day, while Thomasin plays with Samuel, the baby vanishes. A witch in the woods is revealed to have stolen the baby, after which she kills him and uses his blood and fat to make a flying ointment, which she rubs over herself.