Set in early 14th century Wales, Wilkin Brattle, a Welsh knight in the army of King Edward I of England, is betrayed by an Englishman with a lust for power who leaves him for dead. When Brattle is near death, a child apparition implores him to lay down his sword and follow the path of a different man.
Later in life, Brattle lives as a happily married peasant farmer in Wales, awaiting the birth of his child. His new life of peace is shattered by the unbearable taxes assessed on the peasants by “Baron” Erik Ventris, the man who had betrayed Brattle. Pressured by his fellow villagers, Brattle leads a raid on the Baron’s tax collector, which provokes Ventris’ revenge killing of all the women and children in Brattle’s village, and the burning of that village.
Brattle’s raiders battle with the Baron, ending in Ventris’ death and the massacre of his troops. Revenge, however, is not complete, as the raiders want all the soldiers who slaughtered their kin to die by the sword.
Brattle assumes the identity of Gawain Maddox, a journeyman punisher (executioner) injected into the plot just moments before the Baron’s death. Brattle, aka Maddox, enters Castle Ventris intending to identify the remaining murderers so his fellow raiders can exact revenge. However, castle intrigue traps Brattle in his new alias and disdainful profession, forcing him to lead a double life while trying to determine whether this new path is the one the apparition has chosen for him, or if he has been led astray.
The plot partially involves the fallout from the real-life Welsh revolt of 1294–95 against English rule, led by Madog ap Llywelyn.