Captain Alatriste's affair with the beautiful actress Maria de Castro is rankling not only his long-term mistress but also the King of Spain. With loyal companion Inigo distracted by the affections of Angelica, Alatriste becomes embroiled in a series of tussles outside his lover's house. Ambushed by arch-nemesis Malatesta, a skirmish ensues that leads to the death of Maria's other lover - the monarch himself.

But behind this tale of sexual jealousy lurks a darker truth. As it becomes clear that both Alatriste and Inigo have been cunningly honey trapped - and that the dead man was an impostor. With a puppet king waiting dutifully in the wings, Alatriste must use all his cunning and swordsmanly guile to prevent the murder of the real king - and his implication in a crime for which he has been perfectly framed.