At the DEO, Dr. Amelia Hamilton examines Siobhan after Winn brings her in when she uses sonic powers to break a four-story fall. Supergirl suggests that Siobhan should be National City's new story, and tells Winn that her efforts to redeem herself haven't worked. Amelia comes out and tells Supergirl and Winn that Siobhan emitted a sound wave blast broke her fall and pulverized the cement. DNA analysis confirms that Siobhan is human, and she has no idea why the woman has her powers. Siobhan comes out and complains that they couldn't identify what's wrong with her. Winn goes after her and Siobhan wonders how he knows Supergirl. She admits that she's scared, and Winn assures her that they'll figure it out together. Siobhan suddenly winces in pain as she hears a ringing sound and gets a flash of a banshee-like figure howling. She tells that she needs to go and walks out.
As Siobhan leaves, she passes the cell where Lucy is interrogating Livewire about how five people were taken to the hospital suffering from electrical imbalances to the brain. She wonders if the villainess knows anything about it, but Livewire says that she had nothing to do with it. Livewire promises that when she gets out, everyone will pay. A guard finds Siobhan and leads her to the exit.
At CatCo, Cat and Kara open a box of cupcakes. Cat figures that Kara wants one and warns that if she doesn't take one, James will. Kara wonders what she should do, and Cat tells her to make a power move by making James jealous: try less and shine more. She then stops Kara from taking a cupcake.
On the street, Siobhan has another attack. After a moment, it fades and Siobhan turns around and goes to CatCo. Winn sees her but Siobhan shoves him away. Cat tells Kara to call security, and Siobhan tells Kara that she ruined her life. She unleashes a sonic scream, blasting Kara out through the window. James sees it all and screams. As Kara plummets toward the pavement, the Flash speeds down, grabs her, and whisks her out to the country. The friction sets her sweater on fire, and Kara calmly puts it out. She says that she wasn't in danger, and flies off as Supergirl.
Flash speeds after Supergirl and she spots him below. She comes down and the two heroes compare notes. He realizes that he's faster than he thought, and is surprised that Supergirl doesn't know him or Green Arrow. She hasn't heard of any of the heroes and villains that he knows, and Barry removes his mask and introduces himself as Barry Allen. Barry figures that he's on the wrong earth and asks Supergirl for her help.
Later at CatCo, Kara and Barry go to Supergirl's lair and he tries to work out where he is. There's no STAR Labs, Cisco, Harrison, or Caitlin to help him get home. Winn and James come in and Winn says that Siobhan left. Barry introduces himself and Kara explains that her new friend is from another universe. They explain that Kara is an alien and Barry explains how there is a Multiverse and other Earths. If Barry goes fast enough then he can travel between worlds, and Barry runs out to get them ice cream cones in the blink of an eye. James is less than thrilled to learn that there's another superhero. Barry says that he jumped parallel dimensions by accident, so he's stuck there until he figures a way out. Kara assures Barry that she'll help him, and Barry says that he needs food. Kara and Barry go get donuts and Winn points out that James is jealous. James insists that he isn't jealous but Winn doesn't believe it.
As Kara and Barry prepare to leave, Cat calls Kara in and shows her a photo of Flash. She figures that he's competition for Supergirl, and Barry suggests that Flash might be a partner. James and Winn come in, and Cat wonders who Barry is. Once he says that he's Kara's friend, Cat tells James to get photos of Flash while Kara keeps mum until Cat is ready to have her release the exclusive information. She considers names and Barry suggests "Flash." Cat prefers "Blur" and sends everyone but Kara out. Once they're alone, Cat points out to Kara that James isn't happy seeing her with another man, and tells her to keep it up.
Siobhan goes to a fortune teller's shop to ask her aunt Sinead for help. Sinead realizes that her niece is hearing a Banshee calling to her, and explains that all of the women in their family are cursed since before they left Ireland. One of their ancestors stole from a witch, and the only way to stop the curse is to kill whoever is the object of Siobhan's anger. Sinead admits that she killed her husband, and warns that if Siobhan doesn't then the power inside her will grow. It will destroy Siobhan's soul, and Siobhan figures that she'd like to kill Kara. She wonders how she's going to kill Kara if Supergirl is protecting her, and then remembers seeing Livewire at the DEO.
Later, Siobhan shatters Livewire's containment cell from a distance. When the guards run in, Livewire knocks them out and blasts the door circuitry.
Lucy soon calls Kara and warns her that Livewire escapes. Kara tells Cat that she'll take care of all escape arrangements, but Cat refuses to flee. She's sure that Supergirl will save her and tells Kara to believe the same. Kara goes up to the lair and asks Barry for his help. She explains about Livewire and is worried that she can't protect Cat by herself. Kara says that National City needs Flash, and Barry agrees.
Supergirl and Winn meet Flash at the DEO, and Lucy demands to know what's going on. Once Supergirl explains that Flash is there to help, Barry introduces himself and explains that he's a CSI on his Earth. As they go, Supergirl says that she has a sister but doesn't know where she is.
Livewire arrives at an abandoned warehouse via the wiring and Siobhan is waiting for her. Siobhan explains that she broke her out of the DEO and demonstrates her sonic powers. She then says that she drew Livewire there because she wants to kill Kara, and Livewire wants to kill Cat and Supergirl. Livewire agrees and tells Siobhan that she needs a makeover.
James arrives at the DEO and finds Supergirl and Barry working together. Lucy sees James and figures that he's jealous, and James insists that he isn't. He says that he came by to help, and Lucy tells her ex not to hold back with Kara because of her. She says that the two of them weren't fitting, and she forced things by moving there. Supergirl calls out that Barry tracked down Livewire, and he explains that he monitored meter usage to track Livewire to the warehouse. Supergirl says that Livewire is too dangerous for the DEO to take on, and Barry is surprised to learn that Supergirl doesn't have a plan other than punching her. She doesn't want to take the time to prepare a containment device and figures that she can beat Livewire just like she did. Barry agrees and they take off.
Supergirl and Flash enter the warehouse and Livewire appears. Flash speeds around her and then unleashes a blast of lightning. Livewire absorbs it and blasts him into the air and then brings him down. Supergirl starts to use her heat vision on a water sprinkler, but Siobhan unleashes a sonic scream. As Supergirl's ears bleed, Siobhan steps out wearing a costume. Livewire says that her new partner is Silver Banshee, and Supergirl says that she wants to help her. Silver Banshee blasts Supergirl back, but Supergirl and Flash both unleash a wave of air to pin the villains in place. Flash warns that they're not going to win, and both heroes retreat.
Later back at CatCo, Barry checks with Kara and points out that she doesn't seem good. She apologizes for rushing in without a plan, and explains that a few weeks ago she was exposed to red kryptonite and made her crazy. Now the people don’t want her to help them so Kara is too eager to rush in and prove herself. Barry advises her to slow down and keep doing her good work, and not worry about the press. He says that the same thing happened to him and people eventually accepted him again. Barry assures Kara that the solution will happen on its own, and Kara says that she's glad he's there.
James asks Winn where Kara is, and Winn says that she's at the DEO with Barry. Cat tells Winn that she wants Kara to book a massage when she gets back. Livewire teleports into Cat's office and Silver Banshee comes in via the elevator. James runs over and Livewire blasts him down, and Winn tries to get through to Silver Banshee. She insists that it's who she is, but Winn says that she can't keep hurting people. He reminds her of finding out about her father having an affair, and begs her to let him help her. Silver Banshee says that she's good and unleashes a sonic blast.
At the DEO, Barry whips up a pair of earbuds to protect them from Silver Banshee's powers. Lucy lets them know that Silver Banshee and Livewire kidnapped Cat, just as Livewire broadcasts a video that she wants Supergirl to meet them at National City Park to save Cat. Supergirl tells Barry that he doesn't have to help her, but he readily agrees and they speed off.
At the park, Livewire drives everyone out of the park. She prepares to stop Cat's heart with a jolt, and Cat tells her not to do it. Livewire says that she has nothing to mess, and Cat says that she's asking for her boys because she's all they have. Flash and Supergirl arrive and the villainesses attack. The earbuds protect the heroes from Silver Banshee, and Silver Banshee yells at Livewire to attack. Flash knocks them aside and Livewire teleports into the wiring. Flash follows her to a nearby rooftop.
Supergirl frees the handcuffed Cat, and Silver Banshee punches her.
Livewire blasts Flash back.
Supergirl grabs a piece of concrete and throws it at Silver Banshee, who vaporizes it as Livewire returns. A helicopter flies overhead and Livewire blasts it, and Supergirl flies up to absorb the blast as the pedestrians look on. After a moment, Supergirl passes out and crashes to the ground. The pedestrians cheer and tell the villainesses to leave Supergirl alone. Livewire wonders why they're ready to die for Supergirl when they were going to string her up, and a woman says that Supergirl was willing to die for them.
Undeterred, Livewire prepares to attack and Supergirl begs her to stop. Two firemen hit her with water from hose, and the short circuit takes out Silver Banshee as well. Everyone applauds and a fireman helps Supergirl up, saying it was their turn to help her.
Later, the news is filled with reports about Supergirl sacrificing herself for the innocent. At CatCo, Kara tells James and Winn that Barry has told the National City Police Department how to lock up metahumans. She points out that James taught her that their enemies deserve a fair trial, and James says that he's always good for advice. Cat comes out and Kara says that Barry is leaving town and she's going to wish him goodbye. The CEO tells her to tell Barry to have a good time zipping around, and points out that he was obviously a superhero. She insists that she can spot the extraordinary pretending to be a nobody, and tells Kara to book her for an eyebrow waxing
Outside National City, Supergirl meets Barry. He suggests that they join forces and use their combined speed so that he can get back home. They admit that they're going to miss each other, and Barry says that James thinks that Supergirl is cool. He tells her that she shouldn't take things close when it's two people in love, and they hug. The two heroes then race off at their top speeds to reach the necessary velocity, and Supergirl throws Barry ahead of her... providing the speed that he needs to return to his Earth.
That night, James comes by Kara's apartment and she tells him what happened. She talks about how there are an infinite number of Earths, and suggests that if two Earths can merge together, then perhaps two people can get together. When James wonders what she's saying, Kara kisses him. James stares at him and Kara wonders if it was good. After a moment, he walks out without a word. Kara goes after him and sees the other people in the building walking after him.
At the Kryptonian lair, Non receives a report that Myriad has been activated. He vows that first National City and then the entire Earth will belong to them.
Kara watches as everyone in National City marches mindlessly down the streets.
Written by Gadfly on Mar 29, 2016