From Space...

A massive spaceship glides over A-City, halts, and wipes the entire city out. The Sky King lies dead, his body coming apart, as Melzargard, a monstrous alien sprouting several heads and wings, muses over having slain him and admires the devastation the vessel has caused. Iaian drags himself from the wreckage to find A-City in ruins with only the Hero Association headquarters left intact. He glances up at the looming ship for a heartbeat before Melzargard lunges at his skull, only to crush his helmet as its wearer slips clear. Certain the monster's killing intent gave it away, Iaian turns and attacks.

Inside, a panicking Sitch realizes the doomsday prophecy has arrived after watching A-City vanish in an instant. Bang asks why the headquarters still stands, and the answer is that Metal Knight built it far sturdier than a normal shelter, while Metal Bat points out that, like a bomb shelter, it has no windows. As the heroes ready themselves to head out, Genos turns to invite Saitama along and finds him gone, a hole punched clean through the supposedly impenetrable ceiling all the way to the roof.

On the rooftop, Saitama leaps toward the warship and is met with an enormous bullet, which he evades, relieved it was not a laser that might have torched his clothes. More giant rounds follow, and he simply swats them back toward the ship. Meanwhile Iaian keeps fighting Melzargard, whose body shrugs off every strike; the alien wrecks the ground behind him and tears off his arm before splitting into five separate forms. Atomic Samurai arrives to halt the swarm and, worried over Iaian's wounds, engages the regenerating creature himself, gaining ground as the copies grow thrilled that someone can match their power. Bang, Metal Bat, and Puri-Puri Prisoner join him against Melzargard. Elsewhere the S-Class heroes argue over the ship itself; Superalloy Darkshine suggests King take it on, but King declines, which enrages Tatsumaki into deciding to stop the vessel alone. Aboard the ship, Saitama has already killed Groribas with a single punch and resolves to wreck the craft from within, to the horror of Geryuganshoop. The alien leader Boros then appears, shaken to learn Groribas is dead, while Melzargard signals the ship to ready its cannons through a small flying head that Metal Bat promptly destroys, prompting Geryuganshoop to warn of the intruder inside.

An alien warship annihilates A-City, fulfilling Shibabawa's prophecy, and the shapeshifter Melzargard slaughters the Sky King. Iaian, then Atomic Samurai, Bang, Metal Bat, and Puri-Puri Prisoner engage the splitting monster. Saitama boards the ship, deflects its cannon fire, kills Groribas in one blow, and vows to destroy it from inside. The leader Boros appears, and Geryuganshoop alerts the crew to Saitama's presence.

This lengthy thirty-second chapter belongs to the Alien Conquerors Arc and was collected in Volume 6. It appeared online in three parts across December 2013 and January 2014 and spans Episodes 10 and 11 of the anime. In the volume edition it was merged with the online chapter titled Counter.