During the 14th century, Teutonic Knights Behmen and Felson, disillusioned by the brutality of the Crusades, return to a plague-ravaged Europe. Seeking to atone for their past actions, they encounter a dying Cardinal who tasks them with a perilous mission. They must escort a young woman accused of witchcraft to a distant monastery, where monks will determine if her powers are the cause of the plague. Although skeptical of her supernatural abilities, the knights reluctantly agree to the task, knowing the harsh consequences of refusing. They are joined by a group of diverse companions including a grieving knight, a cocky altar boy, a fraudulent guide, and an earnest priest.

As their journey unfolds, the group faces numerous obstacles, both natural and supernatural, which test their resolve and beliefs. The accused woman’s strange behaviors and unexplained occurrences along the way deepen their suspicions and fear, causing tension and discord among them. As they traverse treacherous landscapes and deadly encounters, the truth behind the woman's powers and the plague begins to unravel, leading to revelations that shake the fundamental understanding of their mission. The journey challenges their perceptions, faith, and courage, culminating in a series of confrontations that force them to reconsider their definitions of evil and redemption.