"The Summoning" - - *Sometime after Creation, the universe was split and divided into a multiverse. Each single universe was kept separate from its counterparts by vibrational barriers. History followed similar patterns in most, but each had its own unique trait that made it a universe different from all others.
In July of 1985, anti-matter is devouring the universe of Earth-3, home of the Crime Syndicate of America. Earth-3 itself is being eaten away rapidly by a curtain of pure white anti-matter, while the humans still alive flee its advance.
Suspended in mid-air before the curtain of energy is Pariah, forced to observe the destruction of each universe in the path of the anti-matter, but helpless to interfere. Nor can he even fling himself into the deadly substance to die. When greater danger threatens a universe adjacent to the one he occupies, he is drawn to it. Thus, just before the death of Earth-3, Pariah vanishes to another plane of existence.
On Earth-3 itself, the Crime Syndicate members (Ultraman, Superwoman, Power Ring, Johnny Quick, and Owlman) try in vain to halt the onrushing tide of anti-matter and die, one by one. The planet's only super-hero, Alexander Luthor, returns to the side of his wife, Lois Lane Luthor. They have an infant son, Alexander Jr. Luthor Sr. confesses to his wife that their world is doomed, and that the only hope for their son is to send him, in a dimension-spanning capsule, to another universe. The scientist places his son in the device and sends him to the universe of Earth-1, materializing him in the deserted satellite headquarters of the Justice League of America. The heroes of that Earth, he thinks, will care for his son. With that, Luthor Sr. and Lois die in each other's arms...along with the rest of their world and universe.
Alex Luthor's capsule does indeed appear in the Justice League satellite, but, unknown to Luthor Sr., the headquarters had been abandoned months ago when the old Justice League disbanded. The child is alone.
The scene shifts to another satellite - the one inhabited by the mysterious Monitor and his assistant, Lyla. He has observed the death of Earth-3, and now instructs Lyla to "energize," in order to bring certain super-heroes and super-villains from various Earths to his orbiting HQ. Lyla descends into the core of the satellite, where energy in a special chamber wraps around her and changes her into Harbinger, a multiple, super-powered being. Thus, she can visit many Earths at many points of the time continuum to summon the beings instrumental in the Monitor's plan to save the multiverse.
On Earth-1, in Gorilla City, King Solivar is busy sentencing a murderer to "conversion." Afterward, having retired to his chambers, he is confronted by Harbinger, who takes him in hand, against his will, and vanishes with him back to the satellite.
In the 30th century of Earth-1, Dawnstar of the Legion of Super-Heroes has tracked a mental summons, and an eerie light, to the depths of Suicide Slum in Metropolis. Harbinger's hand reaches through a wall, and causes them both to vanish.
On Earth-2, on April 1st, 1942, at a Manhattan USO bond rally, Danette Reilly is secretly using her flame-power to light a stubborn stove when Harbinger appears to her, transforms her civilian clothes into her Firebrand costume, and summons her to the Monitor. A shadowy figure, unseen by anyone, observes them leaving.
On Earth-4, the Blue Beetle is rescuing a hostage from terrorists when Harbinger appears, gains his willing aid, and takes him to her headquarters.
45000 years ago, on Earth-1, Harbinger appears over the icy stretches surrounding Atlantis, looking for Arion. Before she can locate him, she is attacked and possessed by a shadowy demon.
On Earth-2, in July of 1985, the Harbinger-self who had recruited Firebrand appears in the padded cell of Roger Hayden, the modern Psycho Pirate. Hayden is in a straitjacket due to the painful convulsions he suffers from manipulating and contacting other peoples' emotions. Harbinger relieves him by providing him with the mystic mask with which Dr. Fate once covered his face (which Hayden mistakenly calls the "Medusa Mask"). Then she teleports him, and the unseen Firebrand, to the Monitor's satellite.
Back in ancient Atlantis, Arion feels his once-abated power growing due to recent influx of energy, and conjures up an ice bridge to enable him to cross between two mountain peaks. While he is in the middle of the bridge, the corrupted self of Harbinger alights near him and insists that he accompany her. Thinking her an enemy, he prepares to launch a bolt of sorcery. Harbinger responds by shattering the bridge with her powers and sending Arion plummetting to the ground many feet below. Just before he would have hit, the evil version of Harbinger dematerializes him and herself, to reappear in the Monitor's headquarters.
On present-day Earth-1, Firestorm, at the bidding of Harbinger (who has arrived with the Psycho-Pirate), releases his old enemy Killer Frost from an icy prison. Killer Frost instantly attacks her foe, but the Psycho-Pirate causes her to fall in love with Firestorm. This accomplished, the foursome vanish, as the Monitor watches on his viewscreen. He ruefully muses that his adversary will not allow them much time to act, and already five heroes have perished before he could enlist them. He also notes that Lyla, whom he found 20 years ago, a shipwreck survivor, and whom he loves dearly as a daughter, now must become his killer. Then, she will hold the fate of the entire Multiverse in her hands.
In another chamber, the various beings whom Harbinger has summoned now gather: Blue Beetle, Dawnstar, Solovar, Geo-Force, Cyborg, Psycho-Pirate, Superman of Earth-2, Firebrand, Obsidian, John Stewart (the new Green Lantern of Earth-1), Arion, Dr. Polaris, Psimon, Firestorm and Killer Frost. Their assembly is secretly watched by the shadow-demons, but Psimon senses the presence of these enemies just before they attack. The heroes give vigorous oppositionm but the shadow-beings are resistant to their powers. Finally, a bright light fills the chamber, and the shadow demons are driven off. The Monitor then shuts down his light-weapon, and introduces himself to the assembly. He has summoned them, he says, because their universes are about to die. *Source: The Official Crisis on Infinite Earths Index #1 - Published by ICG