Throughout the career of the Batmen, they have always proved victorious versus the forces of evil. Well, almost always. That event which spawned both the golden and silver age versions of the Dark Knight has always haunted them, the night when they lost their parents Thomas and Martha Wayne at the hands of mugger Joe Chill. At this point in 1981, the Batman of Earth-Two had already died, having prevented another tragedy, the lost of his dear wife Selina "Catwoman" Wayne. In a twist, his counterpart on Earth-One would face a role reversal from his late twin, the chance to save his family... or at least the Waynes of Earth-Five.
When his occasional ally and fellow Justice Leaguer (debatably), the Phantom Stranger, appears with Robin alongside... Batman is offered the opportunity to save this new world's Thomas and Martha. And so, the Dynamic Duo appear on Earth-Five, almost immediately getting in the crosshairs of that Gotham's Police and Lt. James Gordon. After some research, they determine the location of the Wayne family, and track down criminal mastermind Lew Moxon and his hired gun Joe Chill. Neither are the individual who would ultimately confront the Waynes in what would come to be known as Crime Alley. Yet once Batman and Robin deduced that this was the date and time when the tragic event was to occur, the Caped Crusader swooped down to vanquish the would-be mugger assassin. And so, the Wayne family returned to their normal life, although young Bruce Wayne of this world become inspired by the heroic example he had just witnessed.
Although living on an Earth with no heroic legends and in a universe where Krypton apparently didn't exist, it was this young man who would one day adopt the same caped cowl as Earth-Five's future hero. And since the narrative in this story stated what would occur once he was an adult, more than five years in the future when the Crisis on Infinite Earths had occurred, this would prove even further that in one timeline, the Multiverse still existed. As would the Batman of Earth-Five, over a decade later!
An interesting aside, in this tale the Phantom Stranger is seen traversing dimensional planes in the Multiverse... showing he wandered far from his native Earth-One as had his counterpart Sargon who for a period of time left behind his home on Earth-Two. He was also aware of that world's version of the Batman, indicating he may visited that world as well. Both Stranger and Sargon had female foes in Tala and Blue Lama, while the Phantom's arch-enemy Tannarak found a doppleganger on Earth-Two in Azmodus.