The episode begins where the last one left of, with Supergirl and Jimmy surrounded by "Granny" and the three warriors. Supergirl pushes Jimmy out of the way and starts to fight the others. They gang up on her, but she uses that against them by making them accidentally attack each other. She bursts through a wall outside, and the three recover. Meanwhile, the male gang member, Trouble, from before leaves, but Jimmy takes his weapon and convinces the female gang member to help Supergirl.
One of the explosions from the fight causes the ground to shake around Metropolis, and Clark sees the fight. Soon, Superman arrives at the fight in time to catch a metal disk heading towards Supergirl. He is unhappy to see her involved in the fight. Suddenly, the three warriors make one of the buildings fall down, seemingly burying Superman and Supergirl under rubble. Superman gets out, but Supergirl doesn't. He tries to move the rocks, but the three warriors start attacking him. The one warrior has an electric whip, and she shocks Superman until he falls over. Jimmy tries to attack with his weapon, but one of the warriors quickly disarms him. The three warriors and "Granny" carry Superman away through a portal. Supergirl struggles through out of the rubble.
The scene abruptly changes to the other world, Apokolips, where Superman is hooked up in a machine. He questions "Granny," who says that she needs to prepare him to meet "the master."
Back in Metropolis, Jimmy, Supergirl, and the female gang member find the controller that opens the portal between worlds. Supergirl opens it and goes through to save Superman. She hides from guards as she sneaks around. However, some creatures with electric-like powers spot her.
In Metropolis, Jimmy is talking to the female gang member. She says that she doesn't know what "Granny" was doing, but that she kept sending the children out for electronic parts. They bust into a back room that was normally kept locked, where the gang member said she took some of the parts. They look at some sort of machine, amazed.
Supergirl is still in the other world, dodging electric bolts from those chasing her. She pulls out a tube, making part of the building around her collapse on those chasing her, and sending her flying. She drops the portal control, and it is incinerated in one of the columns of fire near her. Supergirl is still being chased, and she stops over one of the columns of fire and spins quickly, causing it to send fire at her attackers. They are down, so Supergirl flies away. She hides behind part of the building, and sees "Granny" and the three warriors exiting, carrying a captured Superman. Granny shocks Superman with the wand to keep him in submission. They do not see Supergirl following close behind.
Superman is taken inside a building, in front of a throne where a man is sitting, Darkseid. Superman is shocked until he kneels in front of Darkseid. He reveals that they have set up machines to cause a meteor to head towards Earth, destroying it without breaking their treaty from before.
Jimmy and the female gang member, back on Earth, watch as the machine activates and pulls the meteor towards Earth. The gang member tries to break the machine, but just gets shocked by electricity from it.
Back on Apokolips, Supergirl bursts out and attacks Granny. She says that she already had one of her worlds destroyed, and she is not going to let it happen to this one. Darkseid attacks her with beams from his eyes. Superman breaks free and attacks Darkseid, causing him to stop shooting the beams at Supergirl. Granny uses the electric wand to shock Superman, causing him to fall to the ground. Now Supergirl gets up, and "Female Furies" attacks her. However, she dodges their attacks, causing them to instead hit each other, and then attacks them herself, using a broken stone column. The one with the electric whip tries to reach her, and Supergirl, in dodging her, rams into Granny, who is forced to release Superman. The warrior uses her electric whip to try and hit Supergirl, but she misses and it wraps around Granny's wand instead, causing it to backfire and shock them both, and Superman. They all are thrown violently down when the wand breaks, causing the shock to end, and leaving all three warriors and Granny defeated.
Darksied says that there is no escape, but Superman grabs the portal controller, and he and Supergirl escape. They are taken back to Earth, conveniently to the room where Jimmy and the gang member are. Supergirl destroys the machine that is pulling the meteor towards Earth. Superman yells at her, because now they cannot use the machine to send the meteor back to Earth, and flies out. Supergirl follows.
Back on Apokolips, the Female Furies, Granny, and Darksied are watching the meteor. Darksied says that "it's entering Earth's atmosphere. Nothing can stop it now!" Superman and Supergirl, back on Earth, watch it coming. Superman tells Supergirl to stay back, and he will try and deflect it. Superman is not making much progress, and the meteor breaks in two. The smaller half is about to hit Metropolis, and Supergirl rams into it, making it explode so that small pieces rain harmlessly on Metropolis. Superman finally pushes out the other half of the meteor, and flies towards Supergirl, who is seemingly unconscious. Superman grabs her in midair and carries her away. On Apokolips, Darkseid turns the Furies on the failed Granny in punishment.
In the Daily Planet office, Jimmy is looking at an article by him on the front page of the newspaper about how Supergirl saved the city and beat Intergang. Lois offers her congratulations, and the staff turns to watch Supergirl outside, flying around the city. Clark tells Jimmy that his cousin is in town, and that he thinks the two would get along fine. The episode ends with Supergirl flying into the sky.