Loyal Spanish soldier Alatriste employs his sword skills for a military group fighting Inquisition abuses. Amidst power struggles of the fading Spanish Empire, he faces conflicts, betrayals, romance, and secrets.

Diego Alatriste is a Spaniard soldier loyal to the royal couple; he puts his talent with the sword to the service of a military organization that opposes abuses during the Inquisition. As a swordsman for hire, he will be in the middle of confrontations, betrayals, romance, and secrets, framed by the struggle for power of the ending Golden Age of the Spanish Empire.