In 1928 New York, the post‑World War I boom also brought a surge of the demonic Sinners, threatening society. The Magdalene Order was founded to oppose this menace, and among its exorcists are Rosette Christopher and her assistant Chrono. Their unconventional nature makes them stand out within the Order, and together they pursue the mystery of Rosette’s missing brother, Joshua. As they delve deeper, their relationships, secrets, and destinies unfold over time.