Superman experiences overwhelming feelings of guilt and regret after killing three Kryptonian criminals.
Not knowing what else to do, Superman leaves Earth and travels through space where he hopes he can find a place where he might never harm anyone again.
During his self-imposed exile, Superman meets new alien races, including a slave-based empire and its leader Mongul who imprisons Superman. As Superman fights for his life in the gladiatorial games, he comes in contact with an old priest who had spent time on Krypton long before it was destroyed. Superman learns more about his planet's past and, in the process, decides that its time to return to Earth.
It’s not easy being Metropolis’ hero, but Superman never faced any threat that made him reevaluate his role until he was asked – by the US president no less – to investigate disappearances in the town of Trudeau. In Tradeau Superman discovers Hfuhruhurr the Word Bringer, who is collecting sentient brains and minds to further his own power. After defeating Hfuhruhurr, the imprisoned minds somehow use Superman’s own body to kill themselves (see The Adventures of Superman Annual #1).
Another difficult task follows later when Superman is called upon to challenge the Time Trapper. In the aftermath of this event, and on an alternative Earth created by the Time Traveller three Kryptonian prisoners escape. Superman eventually subdues the criminals, but they've already destroyed all the inhabitants of the parallel Earth. Overwhelmed by their crime, and unwilling to leave them with any possibility of repeating their crimes, Superman kills all three Kryptonians (see Superman #22).
The realization that he’s killed in haste leaves Superman in a state of self-doubt that only gets worse with time. His encounters with Brainiac – who tries to explore the dark recesses of Superman’s mind – exacerbates the problem (see Superman #25). Superman, and his alter-ego Clark Kent, finds himself continually bedraggled. His tiredness however has a specific cause which Superman discovers, to his dismay: in his sleep Superman is adopting the persona of Gangbuster, and under that guise expressing the violent and vigilante tendencies he never could otherwise (see The Adventures of Superman #450).
Realizing that his mental state is only getting worse, and that soon he might harm those around him, Superman decides to leave Earth immediately. He has no specific destination in mind.
For a long time Superman discovers nothing in space – just dead planets and strange aliens. He even discovers a planet that maybe, just maybe, could serve as his new home, but here too fate conspires against rest and Superman moves on.
A series of chance events lead Superman to a gut wrenchingly familiar sight: an empty world. It’s just like Tradeau, and that means that Hfuhruhurr is somewhere, still stealing minds for his sick cosmic power play. Superman now has a purpose in space, to hunt this monster down.
When Superman does discover Hfuhruhurr he finds that he’s become more powerful than ever; endless arrays of brains in vats fill the enormous space craft. After a long battle against Hfuhruhurr and his proxy powers the minds that make up Hfuhruhurr’s Union turn against him. In the aftermath of the battle the Union minds tell Superman that on Earth he was not taken control of and used to kill the prisoner brains. Instead, the imprisoned Union minds on Earth, in Tradeau, merely subdued Superman and then used their own power to turn the power off to their machines.
In other words Superman committed no crimes at Tradeau. And with that knowledge, the burden Superman has been carrying on his shoulders lightens, if only just a bit.
But even that’s not enough, and Superman continues to lose control of his mind – he is haunted by vivid dreams of those Kryptonians he killed. This loss of focus and weakening as he his air slowly runs out leaves Superman vulnerable, and he is soon captured by minions of the warlord emperor Mongul.
Mongul forces Superman to fight in his gladiatorial games. The fights have been designed to end in death, but Superman refuses to kill, especially not after all that’s happened to him recently. Instead Superman subdues foe after foe, including the warrior Draaga, without killing any of them, and thus infuriates Mongul.
However, while Superman has been captive, one of Mongul’s prison guards recognizes Superman as a Kryptonian and seeks the advice of another: the Cleric. The Cleric telepathically communicates with Superman, telling Superman about Krypton’s history. And when Superman is finally captured by Mongul, the Cleric awakens him, and emboldens Superman to free himself. Once again Mongul’s rule has been challenged by Superman, but this time his people begin to run amok, and Warworld devolves into chaos.
When Superman finally joins up with the Cleric he is given an artifact the Cleric has been holding onto – an old, very old, relic from Krypton: the Eradicator. The Eradicator seems capable of great power, and it is possible that it can teach Superman more about the world of his parents. But more importantly, right now, is the Eradicator’s potential to help Superman overcome his feelings of deep guilt. Through the Eradicator Superman gains a new perspective on his killing of the Kryptonian criminals. Superman still sees it as an act that will burden him, but he also sees that his destiny demands that he renew his mission.
Superman leaves, taking the Eradicator with him. The Cleric is dead, and before departing Superman builds a monument to him; a monument to great guilt and great destiny.
Superman returns home refreshed, but time hasn’t stopped in his absence and some things have changed in Metropolis. On his return Superman must deal with the continued presence of the Gangbuster, as well as Matrix’s impersonation of Clark Kent.
In addition to all that’s transpired in Metropolis, Superman must also deal with what’s changed in his outlook – his dedication to justice and life is reinforced – as well as what Superman’s brought back from space; this includes the Eradicator artifact (see the story arc The Day of the Krypton Man)
Effect on Superman mythology
The Superman: Exile story arc doesn’t substantially change anything about the Superman character. It does however highlight certain streaks in his personality which is important for understanding the post-Byrne Superman mythos. In this modern Superman mythology, the hero is capable of extreme doubt, but is dedicated to his mission for reasons of which he is self-aware: Superman’s mission is an obligation, akin to destiny.
Aside from revealing more of Superman’s personality, the story arc reveals a lot about his Kryptonian history. Readers learn that 200,000 years ago Kryptonians clashed against the religious ideals of a man called the Cleric who spoke out against cloning. Readers learn about the war that occurred then, and that even then there was a genetic abnormality which prevented Kryptonians from leaving their planet alive. This supports Bryne’s Superman mythology, in which Krypton is assuredly not a paradise lost, but rather a restrictive society full of internal problems.