The King of Attolia is the third book featuring Eugenides, the Thief of Eddis. While he is a pivotal character in the novel, the story is primarily told in third person from the point of view of Costis, a young guard reluctantly forced into the personal service of Eugenides, now the King of Attolia.
Eugenides, the Thief of Eddis, marries the Queen of Attolia to bring peace to the two countries. However, since he has married the queen out of his love for her, he is a reluctant king who is regarded as a fool and refuses to be anymore than a figurehead, allowing the Queen to rule as she has always done. He is resented by the Attolia court as a foreigner and upstart.
When the King insults Teleus, the captain of the Guard, Costis, a young soldier in the Queen's Guard knocks down the King and expects to be executed. Instead, the King spares his life and makes him his reluctant confidant. Costis finds the King maddening, obnoxious, and conniving, but slowly he begins to have some sympathy for Eugenides – a very young man, far from his mountain home in Eddis, married to the beautiful but ruthless Queen.
The plot twists and turns through an assassination attempt and various political intrigues involving the traitorous Baron Erondites and his sons; Relius, the Queen’s master of spies; and Eugenides’s old enemy, Nahuseresh of the Mede Empire. Costis begins to realize that there is much more to the King than meets the eye. He gains a clearer understanding of the King’s abilities, motives, and complex relationship with the Queen. With this knowledge, Costis finds his own life and reputation at risk. Surprising revelations continue throughout the book, as the fate of three nations hinges on Eugenides’s internal struggle to accept his own destiny and truly be the King of Attolia.