In Madrid in the 1620s a man must live by his wits, and often by his sword. For this is a time when court intrigue is high, when the decadent young king has dragged the country into a series of disastrous wars, and citizens live in fear of the infamous Spanish Inquisition.

In this political hotbed of hired assassins, court players, political moles, smugglers, and pirates, Captain Alatriste hires out his skills as a dashing swordsman with a mind as sharp as his blade. He is approached by two masked men to fake an attack on a pair of travellers who are stealing into Madrid in the dead of night. But things take a different turn when the Captain realises that this is no ordinary job, but is part of a conspiracy that reaches to the highest levels...