Heretic is the third in the ‘Grail Quest’ series, and it takes Thomas of Hookton south into Gascony and to a final confrontation with his cousin, Guy Vexille. The novel begins with the fall of Calais, and most of the events occur in the subsequent truce, but for Thomas and his companions there can be no truce, only a vicious small war which ends with them being besieged, not just by enemies intent on finding the grail, but by the Black Death.
