In the rural American South during the Great Depression, a sinister, self-proclaimed preacher named Harry Powell is imprisoned for a minor offense, where he shares a cell with a condemned man named Ben Harper. Before his execution, Harper confides in Powell, revealing that he stole $10,000 and hid it, but he doesn't disclose the location. The only ones aware of the money's hiding place are Harper's young children, John and Pearl. After Harper's execution and Powell's release, the predatory preacher tracks down the widow, Willa Harper, with the hidden agenda of locating the stolen fortune. Powell charms the unsuspecting townspeople and woos Willa, swiftly marrying her to get closer to the money.

Within the family home, the relationship between Powell and the children becomes tense as they resist his manipulative tactics. John, protective of his sister and wary of Powell's intentions, clashes with the preacher. Powell exerts a heavy-handed form of spirituality, seeking to break the children's resistance and uncover the secret they guard. As the children hold firm, the family dynamic grows increasingly unstable, with the suspenseful pursuit of the hidden loot turning into a struggle between youthful innocence and malevolent corruption.