A young enameler, Guerric Lefèvre, responds to the desperate plea from his tutor's brother, the prior of Grandmont monastery, to help identify a group of evil lay brothers operating in the priory's newly constructed tithe barn. Asked to masquerade there as a lay brother himself, what he uncovers threatens not only his own life but that of others including the prior. Guerric's task is made even more complex because he has fallen in love with a young woman in the nearby village of Ambazac who weaves habits for the monks but to whom Guerric does not dare reveal who he really is for fear of jeopardizing his original assignment. This story is true to late twelfth-century history when Richard the Lionheart continues his father's, Henry II, patronage of Grandmont. However, in this tale of fiction, King Richard plays a crucial role at the end.