In the first part of the story, Superman discovers Bizarro going on a rampage that results in his suicide, his secret identity as Clark Kent is compromised and exposed to the public, and the Daily Planet is being attacked by an army of Metallos. Meanwhile, Brainiac's metallic skull merges with Lex Luthor's head, taking control of him and leading him to gather the Kryptonite Man in a final showdown at Superman's Fortress of Solitude, where Superman is protecting his remaining friends.
Final issue, becomes Adventures of Superman with issue #424. Story continued in Action Comics #583.
Superman in "Superman" by E. Nelson Bridwell in the Metropolis Mailbag (inside front and back cover).