Part military hero, part privateer, Capt. Alatriste (Viggo Mortensen) fights for imperial Spain and tries to keep a dangerous seductress (Elena Anaya) away from his young squire, Inigo (Unax Ugalde), in this adventure based on Arturo Pérez-Reverte's novels. The film follows 17th-century mercenary Alatriste as he woos beauty María de Castro (Ariadna Gil), honors a promise by keeping Inigo out of the war and plots to destroy his sworn enemy.