Synopsis
The previously page goes all the way back to Avengers #7 to show the Builders' Superflow Web being destroyed. And in our own #6 the Sidera Maris invading Latveria for the Mapmakers. And last issue Yellowjacket returned from the multiverse to say he'd found the Ivory Kings, and they are the Beyonders.
In the Wakandan Necropolis Henry Pym tells the assembled Avengers (Black Panther, Black Widow, Captain America, Captain Marvel, Hawkeye, Manifold, Mr Fantastic and Sunspot - later we'll also see Black Bolt and Hulk) about his trip through the multiverse, including some recordings on a crystal. He went looking for Rabum Alal as the source of the multiversal collapse. But instead he found the Beyonders who are destroying universes for their own purpose.
Black Panther is confused about there being more than 1 Beyonder, and they don't look like the 1 he knows about. No-one disagrees with him, but Yellowjacket says the Beyonder in Secret Wars was a young example who modelled himself after humans. The adult Beyonders are beyond our comprehension.
At 1st YJ wandered aimlessly through the multiverse of alternate Earths, including 1 with intelligent dinosaurs, another populated by Ultrons, a 3rd occupied by Mapmakers (I think), and a 4th being destroyed. But eventually he detected a flow of subatomic particles between timelines (at least that's what I think he meant) and followed it to a surviving Superflow station where Builders from dead universes congregated.
The Builders had linked their Aleph robots together mentally into a hive-mind and sent them out to explore what was left of the multiverse. YJ saw an Aleph on the Superstation report that a source of the multiversal death had been found. The Builders prepared to teleport the station to the co-ordinates, using a Manifold who could make that long jump because the the station 'needed' to be there.
Our Manifold interrupts to ask what 'needed' means. He already knows (because Black Swan told the Illuminati) that there are Manifolds in other universes, but like him they can only teleport themselves and other things within their own universe. But Hank Pym now tells him that the better Manifolds have a sense of where something is supposed to be, and can take it there automatically. And the Builders had genetically bred a Manifold who could do such teleporting across the multiverse.
That Manifold took the Superstation to an Earth where the Sidera Maris were waiting for the Mapmakers. (So it seems the Alephs were just looking for a live incursion of Mapmakers.) The Builders and their servants the Alephs and the Ex Nihili wiped out the Mapmakers and the Sidera Maris. But they decoded the brain of a Mapmaker (who we learned in Av#28 are escaped Adaptoids), and retrieved the map of the multiverse. Using this their Manifold was able to jump them to the Ivory Kings.
At this point in Hank's story Captain Britain joins them. He came as soon as he heard YJ was back. He says that the Mapmakers were a trap set by the Ivory Kings. 4 months ago the CB Corps also captured a Mapmaker and examined it. But instead of following the trail their leader Saturnyne devised a beacon as a lure. The Ivory Kings sent a horde of Mapmakers and Sidera Maris to the extradimensional Starlight Citadel. The Corps were wiped out and our Captain Britain lost an eye. But as a last act Saturnyne implanted the Citadel's knowledge in the eye socket and sent our CB home to Earth-616.
Yellowjacket continues his story. As the Builders & co arrived at their destination he was beginning to wonder why the ultra-powerful Ivory Kings hadn't already destroyed the whole multiverse, if that was what they wanted. Then he found the answer to that. The Ivory Kings were opposed by the Celestials, and the trap was meant for them not puny Builders.
Hank saw his 1st Ivory King fighting and killing the Celestials of the universe they were in. The cosmic conflict weakened the walls between timelines, and Henry Pym saw Celestials dying all over the multiverse. Mr Fantastic realises that this explains why the Celestials broke off contact with the Illuminati, as reported last issue.
Somewhere in all this the Builders, Alephs and Ex Nihili were killed, but shrunken YJ survived. He watched as the Beyonders faced and killed higher powers:- Chaos, Order, the In-Betweener, Infinity and finally Eternity. And then they faced the multiverse embodied as the Living Tribunal. That battle ended with LT dead and splintered into 1 facet in each universe.
Then YJ ran home as fast as he could.