The following version of the book was used to create this study guide: Wheeler, Jeff. The King's Traitor (Kingfountain Series). 47North Seattle, an Amazon trademark, 2016. Kindle AZW file.

This novel is the third installment of the Kinfountain Series by Jeff Wheeler. The story leading up to this point began when Owen Kiskaddon was a young child. Severn, King of Ceredigion, held Owen hostage in an effort to ensure Owen's father's loyalty, and Owen knew that his life was in constant danger. Severn was cruel at this point, but he also had a level of honor. Owen pledged his loyalty to Severn, and the king believed that Owen's value was greater than its actual worth. Severn placed Owen in the care of Stiev Horwath, Duke of North Cumbria and grandfather of Owen's close friend, Evie. Horwath teaches Owen to accept his role as Duke of Westmarch and to be loyal to Severn. By the time the second novel picks up, Owen is seventeen years of age, and he and Evie are in love. Severn refuses to let them marry. Owen falls into despair, seeing Severn fall deeper into the role of the ruthless tyrant who cares for nothing except power.

The people of this world worship the power of the Fountain, a mystical entity that is omniscient and that blesses a select few of the realm with magical powers. Owen is among those. His magic has put him in the position to know that an ancient prophecy has come to fruition through the birth of a man who was robbed of the throne. The child, named Drew, is being raised in secrecy. Drew's father Eyric and his mother Kathryn are at Severn's mercy. The Fountain has told Owen that Drew is the child who will fulfill the prophecy of the Dreadful Deadman. Additionally, it has charged Owen with the responsibility of protecting Drew until he takes the throne. Owen works behind the scenes against Severn, hoping to set up the situation so that Severn will choose to step aside, giving Drew the right to rule. Severn, however, has become too power hungry and ruthless to do the right thing, even when Owen says that Severn is endangering the entire kingdom.

While Owen is surrounded by political intrigue, he is also battling the heartache of losing the only woman he has ever loved. Owen and Evie Mortimer were constant companions as children, and both had expected to marry. Severn refused, knowing that their united duchies would rival Severn's own wealth and power. Evie married Iago, King of Atabyrion, and they have two children. Eve is happy and in love with Iago, though Owen was never able to let go of his heartbreak over losing her. When Owen obeys Severn's command to propose to a duchess named Sinia, he discovers that she has magical powers and has been helping him all along. Sinia fell in love with the person she knew Owen could become. Eventually, Owen is faced with an important decision – to rush to Evie's side after Iago is reported to have died at sea, or to follow through with his betrothal to Sinia. He decides to remain true to Sinia; however, he hurts because he does not provide the comfort Evie wants.

While man-made intrigue is at work in Ceredigion and the neighboring kingdoms, there are also magical forces at work. A magical Wizr set (which is very much like chess) mimics the actions of key players around the world and can be used to control and change situations. When Owen fully understands the power of the Wizr set, he and Drew are able to use the board to place the final blow to Severn's forces. Drew then makes a public show of fulfilling the prophecy by pulling a sword from the fountain at a sanctuary and accepting the crown, making him king of Ceredigion. Drew, Owen, and Sinia take one more ste when they set a wizard named Myrddin free.