1568 was a disastrous year for Emperor Philip II: his son Charles and his wife Elizabeth of Valois died, conflicts in Flanders and the Alpujarras were on the rise, Protestant and Calvinist heresies were spreading in Europe, and the Mediterranean was ravaged by Barbary piracy and the Ottoman resurgence. To face this last threat, the emperor has the largest espionage network known in Christendom, although double agents abound and the Great Turk has at his disposal skillful informers. Luis María Monroy de Villalobos, who has just joined the prestigious military order of the Knights of Alcántara, is already an experienced warrior, traveler and spy. At court, or more precisely in Segovia, he will be commissioned by Philip II in person for a new secret mission: to travel again to Istanbul posing as a wealthy cloth merchant. There are only three years left until the Christian victory at Lepanto.