The "Riddle-Master Series" is a fantasy trilogy written by Patricia A. McKillip, consisting of three novels: "The Riddle-Master of Hed," "Heir of Sea and Fire," and "The Harp of the Grey Rose." The story follows Morgon, a young prince with a mysterious heritage, as he embarks on a quest to uncover his identity and fulfill his destiny. The series is known for its lyrical prose and intricate world-building. Set in the magical land of Hed, the narrative explores themes of identity, power, and the nature of riddles. Throughout his journey, Morgon encounters various characters, including the Riddle-Master and the Harp, who challenge him with riddles that reveal deeper truths. The series is celebrated for its rich imagery and philosophical depth.