Yukon, Canada's far north. A young man tracks a wolf through the wilderness. The one his grandfather warned him about: 'Of all the wolves you will see in your life, one alone will be your master.' In Mexico City, Juan Guillermo has pledged vengeance. For his murdered brother, Carlos. For his parents, sentenced to death by their grief. But in 1960s Mexico justice is sold to the highest bidder, and the Catholic fanatics who killed Carlos are allied to Zunita, a corrupt and influential police commander. If he is to quench his thirst for revenge Juan Guillermo will have to answer his inner call of the wild and discover what links his destiny to a hunter on the other side of America.