In the early 17th century, innocent young Persephone is falsely accused and put on trial for her life. Her fate seems sealed except for the timely intervention of the mysterious Reverend Mother offering her not just sanctuary, but hope. For the Reverend Mother is the self appointed leader of a small religious retreat, a secluded Priory, where her fellow Sisters devote their lives to the Lord and seek atonement for their pasts. But upon arrival, Persephone is plagued with terrifying visions and soon realises that it's not salvation that awaits but a battle for her very soul itself.