S2, E18: Lois's romance with Bruce Wayne (recurring guest star voice Kevin Conroy) disintegrates when she discovers that he is Batman. Meanwhile, Luthor attempts to dissolve his partnership with Joker (recurring guest star voice Mark Hamill), but Joker kidnaps him. When Joker uses the powerful new Lexwing aircraft to attack Metropolis, Superman and Batman must work as a team to stop the remainder of Luthor's killer robots.