The Shattered Castle, By Jennifer A. Nielsen (5th book in the Ascendance Series)
"King Jaron has outwitted the Prozarians and returned to the kingdom with only one secret in his pocket that not even his friends know about. He's hoping that secret will help him finally bring stability to Carthya. But a surprise attack on his own land --- his own castle ---reminds Jaron that nothing is easy. The Prozarian Monarch threatens to crumble Jaron's entire kingdom. And thats not the only thing in danger: With old enemies and new rumors circling around him, even Jarons realationship with Imogen is uncertain. The former False Prince will need his best tricks and many allies at his side to hold Carthya together" "If you play a game with a cheater, you won't win by cheating. You only win by creating new rules. That's what I've got to do," "No one begins to obtain wisdom until they admit they lack knowledge," "Your body takes beatings and rises again and again. Your mind brushes away insults like they are harmless flies....
