Witch Trial, but I Strictly Follow the Meaning of the Instructions

Lee Eun, an ordinary university student, is driven by a mysterious force to a remote island where witches are put on trial. He knows almost nothing about the story, yet is forced to become the one who carries out its commands. Amid suspicion, death, and the shadow of a mastermind, he chooses not to repeat the same mistakes, and to protect everything by his own will.