Synopsis
This issue opens with a page of scenes from the previous 2 issues, establishing the expanded Avengers team and the core team captive on Mars, facing the alien trio who will either transform or destroy the Earth.
On Mars (in the area they bio-transformed) the aliens are awaiting the birth of their humanoid Adam, whom Ex Nihilo wants to inherit the Earth. The mechanoid Aleph on the other hand will destroy the Earth if Ex Nihilo's plan fails. Meanwhile Ex Nihilo's sister Abyss proposes to the captive Thor that they abandon both courses and start their own pantheon of gods. Thor's only response is to offer to save Abyss when the Avengers defeat the aliens.
Adam chooses this moment to burst forth fully-formed from his cocoon of bubbles. Unexpectedly he starts babbling in what Ex Nihilo recognises as Builder machine code, before falling unconscious. (In #2 we learned that the Builders were the 1st sentient race in the universe, who built a swarm of Aleph mechanoids to spread through the cosmos passing judgement on other sentient races.)
The next interruption is Hyperion eye-blasting Ex Nihilo. He has arrived with Captain America and Smasher. Cap takes on Aleph, in revenge for the pounding he got in #1. But eventually a blast sends him reeling. Abyss meanwhile sets her hypnotised lackey Hulk on Hyperion. Smasher is standing ready to attack Aleph or the downed Ex Nihilo, when suddenly other bubble-pods burst open, unleashing wolf-like and pterodactyl-like creatures.
Cap finds himself next to the captive Iron Man. Tony Stark asks him why he didn't bring all the new Avengers team. Steve Rogers' response is to signal Manifold to teleport in the rest of them.
Captain Marvel disperses the squad into an attack formation. But Captain Universe is disoriented by the teleportation, and her human(?) personality starts to resurface. The rest of the team (including Cannonball, Spider-Woman and Sunspot) attack the horde of creatures, as Hyperion continues to fight Hulk. Smasher demonstrates some of her Imperial Guard tech, as the beam from her Exo-Specs ricochets around taking out several wolves at once.
Meanwhile Cap and Spider-Man attempt to free the captives (Black Widow and Hawkeye as well as Iron Man and Thor) from the ultra-tough vegetation that holds them. They don't get very far until they're joined by Wolverine's claws.
Falcon has held strangely apart from the conflict. He has been communicating with the bird-like creatures, and they have communed with their wolf brothers. Now all the animals abandon the fight.
Sensing defeat, Abyss and Ex Nihilo give way to Aleph's desire for extermination. But Wolverine has freed Thor, who gains repossession of his hammer. A lightning strike hits the 3 aliens. Abyss loses control of Hulk, who transforms back to Bruce Banner. Aleph has started growing to giant-size. But a strike from Shang-Chi cuts him off at the knees.
Aleph and Ex Nihilo continue blasting at the Avengers, from under a defensive shield probably formed by Abyss. But Captain Universe has been talking with Adam. Suddenly she appears in front of the 3 aliens, who bow down to her as the Mother Goddess (the Universe) of the Builders. She tells them to stop judging worlds (not just Earth).
But the mechanoid Aleph refuses to believe her divinity. (We were told last issue that the Builders had stopped believing in the Goddess before they sent the Aleph's out.) (Or maybe it's because Captain Universe keeps slipping back into her confused alter ego.) Aleph questions her orders, then tries to attack her. But the Captain reduces it to its components.
The Avengers leave Mars to Abyss and Ex Nihilo, as long as they stop attacking Earth. They take Adam back to Earth with them.
We end with some lines echoing #1, but over different visuals, saying that Steve and Tony started a legend when they created the new Avengers lineup. But a new bit claims that Cap represents life, while Iron Man is death.