Almost immediately after Caleb's death, Mercy and Jonas — who are twins and the youngest members of the family — say it was Thomasin who killed him. They accuse Thomasin of being the witch. William, the father and the patriarch of the household, turns on her almost immediately, asking her if it's true. She swears up and down it's not her. When the twins are suddenly rendered immobile and unresponsive though, he doesn't believe her.
William drags all of his remaining children — Thomasin, Mercy, and Jonas — outside, trying to figure out the source of the evil witchcraft. The twins continue to insist it's Thomasin, but she quickly fires back, saying they've been talking to the family goat, Black Phillip. It's true — the twins have been whispering to the goat for the entirety of the movie. Unable to reach a consensus as to who's actually evil, William locks all of them in the stable with Black Phillip.