The Black Robe delves into themes of religious manipulation, obsession, and the conflict between faith and reason. The story follows Lewis Romayne, a man troubled by guilt and illness, who becomes a target of a Jesuit priest determined to convert him. As Romayne is drawn deeper into the schemes of the Catholic Church, his relationships and beliefs are tested. Collins combines psychological tension with Gothic elements, creating a gripping exploration of religious influence and personal autonomy.