Germany, Cologne, 1390 a.d. A prosperous city, rare crimes, boredom and idleness reign in the local branch of the Inquisition. Young investigator Kurt Hesse, recently transferred here, languishing from idleness, seizes on a completely ordinary, at first glance, incident - the death in his sleep of a local university student. The aspiring inquisitor will have to plunge into the life of the student fraternity, enter into a dangerous game with the highest nobility and clergy, and make a close acquaintance with Countess Palatine Margaret von Schönborn. Will his heart or mind be his guide when he faces the most terrible choice that an investigator of the Congregation can face?