 Obi-Wan appears in spirit form in many novels set after "Return of the Jedi".In "The Truce at Bakura", he appears to Luke to warn him about the threat presented by the Ssi-ruuk; in "The Lost City of the Jedi", he guides Luke to the titular city on Yavin IV; in "Heir to the Empire", meanwhile, he bids farewell to Luke, explaining that he must abandon his spiritual form to "move on" to a new, higher plane of consciousness.Before parting, Luke says that Obi-Wan was like a father to him, and Obi-Wan replies that he loved Luke like a son.