Kara recharges under sun lamps after returning from the Phantom Zone. She has nightmares of her time there.
The Super Friends throw Kara a welcome home party.
Zor-El decides to stay in National City for a bit to spend time with Kara before leaving for Argo City. Kara tells people that he is her Uncle Archie visiting from Midvale.
Kara returns to CatCo, which has fallen to number eight in a national ranking of news sources. Andrea threatens to have the news staff replaced if they aren't number one by next month's ranking.
Andrea tells Kara that she wants an exclusive with Supergirl and how she stopped the National City phantom attacks.
William tells Kara that he has been seeing someone.
A satellite breaks through the Earth's atmosphere. Kara and Zor-El prevent most of it from reaching the surface.
A piece of the satellite hits an island of garbage a thousand miles off the coast of National City and it catches fire. Corporations, including the DEO, are illegally dumping there.
Kara brings the story to Andrea, but she gives it to William.
William cannot find evidence that proves Lex is to blame for the garbage island.
Zor-El worries about the climate crisis on Earth.
Kara takes Zor-El to the Fortress of Solitude. Zor-El figures out that Earth is on the same path as Krypton was before it exploded.
They bring back Kelex, now renamed Oscar, and Zor-El modifies him to clean Earth's oceans.
Andrea uses her powers as Acrata to break into Lex's mansion. She finds files on Supergirl, J'onn, and Sentinel.
Oscar malfunctions as garbage is added to his body. The Super Friends cannot trace him. Kara and J'onn leave to find him.
Oscar starts to overload, which will eventually make him explode with the force of an atomic bomb if the Super Friends don't stop him.
Oscar, now a huge garbage monster, appears on land. Brainy loads a drone with a virus and defeats Oscar.
Kara takes Kelex back to the fortress.
Brainy takes Zor-El to Argo City.
Andrea publishes William's article even though it doesn't trash Lex. She wants William to do an expose on Supergirl and her friends.
Lena goes home to where she was born to find out more about her mother.
Nia has a dream about Nyxly.