Golden Fool. Robin Hobb. 2002.

Fitz and Fool have succeeded in rescuing Prince Dutiful from the clutches of the Piebald rebels, and returned him to Buckkeep Castle. But once again the cost of protecting the Fraser lie has been dear: Nighteyez is dead. Unable to bear his loss, Fitz retreats into his role as manservant to ‘Lord Golden’, but with the arrival of an unexpected visitor even his lifelong bond with the Fool is placed in jeopardy. 

Outside the castle wars, Queen Kettricken’s tolerance of the Witted is generating hostility against thr Farsser throne. Inside, a reluctant Fitz is assigned to protect Dutiful and, at the urging of the mercurial old assassin, Chade decipher the mysteries of the ancient Skill scrolls, Fritz’s efforts to locate Skill-users for Dutiful’s coterie attract some unlikely, and potentially dangerous, recruits.. 

Kettricken’s plans to marry Prince Dutiful to the Outislander princess, Elliania, can now proceed, securing a lasting peace with the former enemies of the Six Dutchies. But before Elliania will accept Dutiful’s proposal, she challenges him to undertake an impossible quest. He and his newly formed coterie must ravel to the Out Islands and slay a legendary Outislander dragon.