The Witch follows the early mass hysteria of the people in the mid 1600's in New England, a time in which women were being persecuted and attacked over the assumption of using, or having used, witchcraft.
William and his family have been banished from their Puritan plantation, and decide to develop a small, independent farm on the outskirts of a large forest. The eldest daughter, Thomasin, plays with the family's latest child shortly before he disappears. William sells his wife's silver cup for hunting supplies, but the disappearance of the cup gives Katherine the impression that Thomasin is responsible for both the cup and child's disappearance.
The Witch perfectly displays the mass hysteria surrounding witchcraft of the era, as well as the fragility of such accusations; a simple accusation of witchcraft could send a family spiralling downward into a world of distrust and hate, with witchcraft once again being the reasoning for such events occurring.
The viewer is constantly pulled alongside that mass hysteria as the two youngest children begin to make claims that they can and have talked with Black Philip, the family goat. One of the children is later lured into a small hut within the forest by an attractive woman, ultimately verifying the existence of witches and witchcraft to the viewer--the characters later discover what had happened to Caleb, but the blame is pinned on Thomasin.
With the viewer aware of Thomasin's innocence, the film's events continue to escalate with Black Philip being the main reason behind them all, although it is clear that Thomasin is close to hitting a breaking point: the way she has been treated has her wanting revenge.
The Witch is well worth a watch this October, with its ending, in my opinion, being close to perfection. It shows that evil isn't primarily bound to witches, but humanity as a whole.