In 1347, the English capture Calais and the war with France is suspended by a truce. But for Thomas of Hookton, there is no end to the fighting. He is pursuing the grail, the most sacred of Christendom's relics, and is sent to his ancestral homeland, Gascony, to engineer a confrontation with his deadliest enemy, Guy Vexille. Thomas becomes a raider, leading his archers in savage forays. But Thomas becomes the hunted as his campaign is destroyed by the church. With only one companion, a girl condemned to burn as a heretic, Thomas goes to the valley of Astarac where he believes the grail might be concealed, and plays a deadly game of hide and seek with an overwhelming enemy. Then, just as Thomas succeeds in meeting his enemy, fate intervenes as the deadliest plague in the history of mankind erupts into Europe.