In a remote Welsh village during the 14th century, a young girl named Alice, aged sixteen, finds herself accused of witchcraft and blamed for the plague that has devastated the community, claiming numerous lives, including that of her father. When it comes to light that Alice has been concealing her mother’s illness, she is forced to witness a sinister masked figure known as The Cleanser mercilessly execute her mother. The village preacher, Tom, who also acts as the leader, harbors feelings for Alice and subjects her to five cruel trials after she rejects his advances. With the aid of her mother’s friend Mary, Alice escapes the night before her scheduled execution and seeks refuge in the forest. There, she stumbles upon the hidden dwelling of a mysterious healer, who is burdened by his own past and inner struggles. He helps her recover and imparts the knowledge she needs to seek vengeance on those who wronged her.