Winter 1264. England is in turmoil. King Henry III's reign is under threat. In Oxford the barons prepare to challenge his rule. Searching for his lodgings down a dark alley, young student Thomas Symon hears a scream. It's a young girl, her throat slit. Mistaken for the fleeing killer, Thomas is saved from a vengeful town mob by a stranger pulling him into a dark passageway. The man is his new university tutor, renowned academic Regent Master William Falconer, who has earned a reputation for unpicking the most complex academic puzzles. Now, to save his student, he must find a killer. But time is running out - this is a killer on a quest, and to save another victim Falconer must find the link between the murders. . .