Appearing in "Whatever Happened to the Man of Tomorrow?"
- Superman/Clark Kent of Earth-423 (First appearance)
- Lois Lane Elliot of Earth-423 (First appearance) (Flashback and main story) (Narrator)
- Jimmy Olsen of Earth-423 (First appearance)
- Lana Lang of Earth-423 (First appearance)
- Josh Coyle of Earth-423 (Single appearance) (Unnamed)
- Pete Ross of Earth-423 (Single appearance) (Appears only as a corpse)
- Perry White of Earth-423 (First appearance)
- Alice White of Earth-423 (First appearance)
- Krypto of Earth-423 (First appearance)
- Legion of Super-Heroes of Earth-423 (Single appearance)
- Streaky of Earth-423 (Mentioned only)
- Bizarro No. 1 of Earth-423 (Only appearance; dies)
- Brainiac of Earth-423 (First appearance) (Destroyed)
- Kryptonite Man of Earth-423 (First appearance)
- Lex Luthor of Earth-423 (First appearance)
- Metallo Army (Single appearance)
- Metallo (Roger Corben) of Earth-423 (Single appearance)
- The Prankster of Earth-423 (Single appearance)
- The Toyman of Earth-423 (Single appearance)
- Jonathan Elliot (First appearance) (Cameo) (Unnamed)
- Metropolis Fire Department
- Tim Crane (First appearance)
- Metallo (John Corben) of Earth-423 (Mentioned only)
- Parasite of Earth-423 (Mentioned only) (Deceased)
- Terra-Man of Earth-423 (Mentioned only) (Deceased)
- 30th Century (Mentioned only)
- Krypton (Mentioned only)
- Bizarro World (Mentioned only) (Destroyed)
Synopsis for "Whatever Happened to the Man of Tomorrow?"
One day in 1987, Superman returned from space to find Metropolis had suffered major damage, which Lois Lane and Jimmy Olsen said came from Bizarro. Superman enters a wrecked department store and confronts Bizarro, demanding an explanation for all the death and destruction. Bizarro explains his reasons to Superman: he had recently realized that all these years, he has not been a "perfect imperfect duplicate", and so he took the necessary steps to fix that. Realizing that Superman came from an alien world that was destroyed by a natural accident, Bizarro destroyed Bizarro World then attempted to destroy his own birth world starting with Metropolis. Then, realizing that Superman never kills anyone (even bad people), Bizarro went on a killing spree through the city, murdering several innocent men, women, and children. Finally, Bizarro states that since Superman must live, then he himself must die. He holds up a chunk of Blue Kryptonite and presses it against his chest, fatally exposing himself to its poisonous radiation. Bizarro bids a final cryptic farewell to his longtime rival, then quietly passes away from Kryptonite poisoning, leaving Superman, shocked, confused, and saddened over what has just happened.
Following this bizarre incident, Clark Kent gets ready to join his co-anchor Lana Lang in the WGBS news room when he receives two packages. The first smaller package is a group of Superman action figures that come to life, firing deadly heat-vision beams. The production crew watch as Clark Kent is attacked by the action figures' heat vision, figuring that he would never survive, when they saw that they exposed his Superman identity to them. The action figures now also speak in the voices of the Toyman and the Prankster, the two villains behind this attack. They have Superman open up the second package, which contains the dead body of Pete Ross, whom the two criminals have extracted information about Superman from. Superman finds out where the two criminals are hiding and bring them to justice, but as his civilian identity is now compromised, he fears that as the villains who were nuisances to him were becoming killers, he can only wonder what will become of those who are killers.
Speaking of which, Lex Luthor was up around the North Pole area where he finds the inert head of Brainiac in his robotic skeletal form when parts of his head started attaching themselves to Luthor's head, taking control of him. Brainiac now reveals that he is taking control of Luthor's body as part of a new form of partnership between the two, and that now he is seeking revenge against Superman for what he had done to him. Brainiac now guides Luthor's body back to civilization where he is to build a new ship for the robot.
Back in Metropolis, a group of men gather around outside the Daily Planet building on a hot day when they start shooting harpoons from their chest, revealing themselves to be humans converted into Metallos. They assault the staff of the Daily Planet and cause Lois Lane to fall from a window when Superman appears to rescue her and to magnetize the Daily Planet globe to capture all the Metallos inside the building. When that was done, Superman transported Lois, Jimmy, Lana, Perry White, and his wife to his Fortress of Solitude where they would be safe. As they were escaping the city, the merged Brainiac/Luthor shows up in a smaller version of Brainiac's Skull Ship to pick up Kryptonite Man as he appears calling out for Superman to challenge him.
That night, as Perry and his wife sleep in separate rooms, and Lana and Lois hold each other while crying themselves to sleep, Superman is joined by his dog Krypto as the Legion of Super-Heroes' time bubble appears, bringing with the group a young version of Supergirl who has yet to know that she has died. Brainiac 5 presents Superman with a special memorial trophy, seemingly as if they were never going to see him alive again after this. Following their departure, Superman buried his face in his hand and cries.
- Continued in Action Comics #583.
- Superman in "Superman" a brief overview of the Superman comic book by E. Nelson Bridwell on the inside front and back covers.
- This is the final issue of the series under its original print run. The numbering sequence continues as Adventures of Superman (Volume 1). In 2006, the series reverted back to its original title beginning with issue #650.
- This issue was reprinted in Across the Universe - The DC Universe Stories of Alan Moore and Whatever Happened to the Man of Tomorrow?.
- Whatever Happened to the Man of Tomorrow? was originally published as an imaginary story, a story outside of regular continuity. In Crisis on Infinite Earths: The Compendium, it was retconned as having happened on another Earth, (Earth-423). It takes place in the year 1997. The two-part saga is intended to represent the "final" Superman story, but does not actually take place within canonical Earth-One history.
- Regardless of DC's editorial intentions, this "final" Superman story was presented by DC as being an "Imaginary Story", a Silver Age convention, revived especially for this occasion, that served to tell "What If?" stories that would have been considered series-killers if they were to happen in the "real" continuity of the comic.
- The cover is a homage to the covers of the first eight Superman Annuals.
- The Crisis on Infinite Earths: The Compendium would retcon all Imaginary Stories as happening on various other Earths and therefore out of continuity for Earth-One.
- The story opens with a brief legend that ends thus: "This is an Imaginary Story... Aren't they all?"
- Superman Recommended Reading
- Action Comics (Volume 1)
- Action Comics (Volume 2)
- Adventures of Superman (Volume 1)
- Batman/Superman (Volume 1)
- Batman/Superman (Volume 2)
- DC Comics Presents (Volume 1)
- Superman (Volume 1)
- Superman (Volume 2)
- Superman (Volume 3)
- Superman (Volume 4)
- Superman (Volume 5)
- Superman/Batman (Volume 1)
- Superman Confidential (Volume 1)
- Superman: The Man of Steel (Volume 1)
- Superman: The Man of Tomorrow (Volume 1)
- Superman/Wonder Woman (Volume 1)
- World's Finest (Volume 1)