Action Comics #660 1990

Action Comics #660 presents the pivotal story 'Certain Death,' where a gravely ill Lex Luthor orchestrates his apparent demise in a plane crash. Superman investigates the wreckage, contemplating the implications of his arch-nemesis's passing and his own secret identity. This issue is highly notable to collectors as it features the significant, albeit temporary, death of Lex Luthor within the Post-Crisis continuity, marking a dramatic turning point in the Superman mythos.