The gang is back together, camping out in a bunker in the Outlands. Lyta is spilling the tea on General Zod and his plans for the future: He's going to use Doomsday to obliterate any dissenting alien civilizations, and then colonize their planets. Guy's get an Edifice Complex.
Seg and Nyssa team up to make it back to Wegthor to warn the rebels before the next onslaught. Lyta's too sick to go, so Seg teams up with Nyssa. Seeing him and Lyta back together is hard for Nyssa, who's really kind of in love with the guy. Tough breaks. But hey, it's nothing that a ride in a skimmer can't fix.
Meanwhile, General Zod is unleashing Doomsday, hoping that there's enough Black Mercy toxin in his system to keep him under control. Is there? We'll find out. And in the sick bay in the Outlands, Jayna is nursing her daughter back to health — the Black Mercy left a bad taste in her entire body. It also gives them some time to talk about how they were awful to each other, and to heal past wounds.
Seg and Nyssa make it up to Wegthor without issue, and notify Val and the other top brass of the imminent attack from Zod's fleet. It's go time, baby! They're going to lure Doomsday into the tunnels, then detonate the tunnels.
Speaking of, a few minutes later Doomsday makes his grand entrance on Wegthor. That's when the rebels rain hell upon the creature. And that's when Doomsday fights back, and busts butt, before making his way into the tunnels.
Back on Krypton, two Sagitari bust into the sick bay to find Lyta. Jayna and Dev bring them to their knees, and when Lyta tells them about Zod, the cloning, etc., they disavow him and swear loyalty to her. New recruits!
Wegthor's lost power thanks to Doomsday's knocking about. This spells trouble for Seg and the rest of the crew underground. That's when Doomsday busts through the tunnels and annihilates a small cavalry of rebels. Meanwhile, Seg and Kem are knocked out by Doomsday's entrance, just after Seg initiated countdown for a bomb.
And aboveground, Nyssa leads the rebels in an assault onto the Sagitari flagship. And after the explosion, Adam and Val were trapped under some rubble. But it was Adam who lost feeling in his legs.
When Seg and Kem wake up and get to safety, they realize that the detonator's missing. So Kem sacrifices himself to go and find it, allowing Seg to escape on the skimmer. So after getting impaled, Kem comes face-to-face with old Doomsday, and lights him up like a Roman Candle. Just as the rebel have commandeered the Sagitari ship, they get to watch Wegthor shatter into a bajillion pieces.