In a society, the proud and arrogant Golden Age Spain, riding blind towards the end of the Empire and in which the honor and loyalty are all, a Spanish soldier who has travelled Europe fighting under the flag of "Tercio Viejo de Cartagena", survives in the Austrias' Madrid as a mercenary swordsman hired four coppers on request. Brave, honest and loyal man, Diego Alatriste will be involved in intrigues and conspiracies of various kinds that require him to make good use of his steel.