Mexico City, 1649. The Spanish Inquisition holds sway over the capital. Fray Alonso is the most zealous advocate of their mission; amidst the veiled discords of the Holy Office, his diary reveals a world where politics and sanctity are intertwined as he seeks to win the promotion that will gratify his aspirations of both stature and piety. However, outmanoeuvred by his rivals in a struggle for power, Alonso is forced to leave the city on a seemingly futile journey northward, where an unlikely friendship with a captured heretic will prove the catalyst for a revolution of his assumptions. Alonso is forced to question all his received values, and is left with a choice between instinctual justice and his own pride and desire. The bond between the two men proves to be simultaneously a blessing and a test.