Heretic

Thomas of Hookton returns to Gascony after the fall of Calais and captures the fortress of Castillon d’Arbizon, hoping to draw Guy Vexille and other seekers of the Holy Grail into the open. His command of a small company places him amid raids, local feuds and a siege in which military necessity is complicated by accusations of heresy.

As the besiegers close around the fortress, the Black Death reaches the region and overturns the balance between attackers and defenders. Thomas must confront his cousin, the churchmen hunting him and the possibility that the Grail is more dangerous as an idea than as a relic.