Supergirl kicks off with Guardian stopping two muggers from robbing a woman, but she is afraid of the vigilante and runs off. Lena and Kat are having breakfast as Lena tells her about her new partnership with a new business associate (Rhea) before getting a call from Rhea and takes off. Winn meets up with James during lunch to ask what happened last night as he tells Winn that the woman was terrified of Guardian and that this isn’t the first time.
An alien woman suddenly starts causing a storm with her eyes, but Supergirl shows up just in the right time to save the day. The D.E.O. learns that the woman is a Forrian, an alien race known for usually being peaceful and has the powers of telepathy and telekinesis. James wants to help, but J’onn tells him that Guardian’s services aren’t needed right now. Later that day, Rhea and Lena are having dinner while discussing their business plan about the portal technology. While Lena is disappointed about not being able to move the progress faster, Rhea tries to get Lena to not be so hard on herself. Mon-El spots his mom leaving the restaurant as he gets curious what she is up to.
Elsewhere, Guardian interrupts the alien Brian from buying off some weed from a dealer. In order to save his own skin, Brian tells Guardian that he knows about where the Forrian woman lives. Guardian heads over to her home to investigate, but spots a young boy trying to escape as he is afraid of him. James assures him he won’t hurt the boy as he takes off his helmet to calm the kid down. The boy is taken to the D.E.O. where Alex tries to get answers on where his mother is at so they can help them both. Alex joins the others later on and says that she can’t get anything out of him, but realizes that it is James that the boy, whose name is Marcus, seems to trust.
James takes Marcus to CatCo where they meet Kara, but Marcus is still not speaking. Marcus is posed as James’ nephew to the CatCo employers as he starts exploring James’ office. Marcus uses his abilities to play with a board game, before discovering James’ cameras as James tells him the story of how he was inspired to become a photographer before his dad died. Suddenly, Marcus starts speaking and tells James what happened to his father on their home planet. Mon-El shows up with lunch for Kara to tell her that he thought he spotted Rhea last night. But Winn confirmed to Mon-El that his parents ship were nowhere on Earth.
Marcus suddenly sees his mom on the news as they are labeling her as an “alien terrorist” and James tries again to find out where she is. While James speaks with Eva, Marcus starts using his abilities and causes a big storm in the office that does damage to the building. It seems to have something to do with Lena’s experiment to get the portal to work at L-Corp. Kara changes into Supergirl and gets Marcus out of the office. Lena and Rhea believe the experiment was successful and shuts down the portal as Marcus gets in control of his powers again. They take him back to the D.E.O. as they believe something is making Marcus’ powers to go wild. Winn discovers what it is in the atmosphere that is causing Forrians to go wild with their abilities.
J’onn tries to convince James to stay and keep trying to get through to Marcus, but James doesn’t know what to do. James is told the story of when J’onn felt helpless on Mars with a situation regarding his daughter, before he became the Martian Manhunter. Kara thinks it might be Lena’s new project that is causing the spike in the atmosphere and decides to give her a call, but Rhea answers Lena’s phone as Kara is stunned to learn that Mon-El’s mom is still on Earth. Rhea has her villain monologue while the D.E.O. tries to track where she is located at. Mon-El tries to talk sense to his mother, but she won’t hear it as Rhea hangs up. Rhea also deletes Kara’s contact information on Lena’s phone.
James goes back to Marcus’ cell and tries to find out what is going on, in order to help his mother. Marcus explains that he and his mom have been trying to find a safe planet to live on, but that they keep being hunted wherever they go. James tells Marcus that he used to be bullied as a child because of his skin color and how his father helped him feel safe despite being bullied. When he died, James didn’t really let anyone in his life before he moved to Metropolis and met Superman who helped him open up again. He asks Marcus to let James be a friend to him so he can help Marcus and his mom. Marcus agrees to take him to his mom as long as James promises that she won’t be harmed. James tries to convince J’onn to let Marcus leave the D.E.O. so Marcus can take them to his mother and eventually J’onn agrees to let them go, with Winn bringing a mobile version of the telekinesis dampener.
Winn and James follow Marcus who takes them to his mother and they assure her that they are on their side. But Marcus’ mom isn’t alone as the building has several Forrians hiding there too that James and Winn need to help. At L-Corp, Rhea offers some comforting words to Lena before activating the portal once again while Winn tries to activate the dampener, but it’s not strong enough as the Forrians’ powers go wild again. James realizes that if he can get through to Marcus, he can get the telekinetic connection stable again.
Mon-El, Supergirl and J’onn show up at L-Corp as they try to stop Rhea. Kara begins to fight her as Rhea is bringing “something” through the portal. J’onn tries to stop Rhea, but she uses technology that she got from a White Martian that gets Green Martians trapped inside their own minds. Mon-El pulls a gun on Rhea as he informs her that Daxams are vulnerable on Earth. Rhea starts messing with her son’s mind by asking if a hero of Earth would really kill his own mother, which seems to get to him. He asks Rhea where his father is as Rhea lies to him that he committed suicide when Mon-El decided to not go back to Daxam. Mon-El lowers his gun while James manages to get through to Marcus as he and all the other Forrians get in control of their powers again.
We then start seeing several space ships come through the portal as Rhea has brought Daxamite refugees to Earth. As they all arrive in National City, Rhea welcomes her people to the New Daxam as the episode cuts to black. There was a lot that went down in tonight’s intense episode that we have to discuss. So let’s go through the top 5 highlights and important moments of the Supergirl Season 2 episode: “City Of Lost Children”