Pop quiz: What do you get when you combine two kickass superheroes and a couple of vicious villains? Answer: A pretty fantastic crossover episode! So strap in, Karaphiles and Speedsters, and get ready for worlds to collide on this week's Supergirl (featuring the Flash).
After Siobhan used her voice to save herself from quite literally plunging to her death last week, Kara and the DEO are anxious to figure out what exactly she is and how she did what she did. Kara tells Winn that Siobhan isn't a Fort Rozz escapee and since she also isn't from Krypton, they're not sure exactly where she's from. Winn, however, is still convinced that she's superhuman, which prompts Kara to state that maybe she should be National City's new hero.
It's clear that after her brush with the dark side, the public still hasn't forgiven Supergirl, despite Kara's efforts to win back their trust. Winn tells her that it wasn't her fault but Kara says that the public doesn't know about the circumstances.
The doctor tells Kara and Winn that Siobhan used her voice to cushion her fall and save herself. The real kicker, however, is the fact that Siobhan's DNA proves that she's human. Siobhan isn't to pleased with the lack of information and decides to leave. When Winn follows her, she asks him how long he's known Supergirl and he says he would have told her had they actually gone on a real date. He tells her that they'll figure everything out together. Before she can accept his comfort, however, she gets a headache and leaves.
Meanwhile, Lucy questions Livewire about five people who were hospitalized due to electrical imbalances in the brain. She wants to know how Livewire managed to hurt them from her sell but Livewire says that the only victims she's interested in hurting are Cat and Supergirl.
Back at CatCo, Cat uses cupcakes as a metaphor for Kara's love life, telling her that instead of hanging back and longing for James from a distance, she should make herself unavailable in order to make him jealous. At the same time, Siobhan is still struggling with her headaches, only this time they're accompanied by visions of a creepy decrepit woman. Just like before, her headaches end with a jolt and Siobhan marches off, as if possessed, to CatCo in order to confront Kara.
Winn tries to stop her, especially since she was banned. When Kara tells her to leave, Siobhan uses her voice to push Kara out the window. Before she can save herself, however, she's whooshed away to the desert by a mysterious, lovable red streak. Enter the Flash! Kara tells him that she didn't him to save her, then proves it, much to Barry's surprise, by taking off back to the city. Naturally, Barry chases her down and they both seem in awe of each other.
After they introduce themselves, Barry realizes that not only does she not know about the Flash, but she doesn't know about any of the heroes that have been lighting up television screens via the CW. After a beat, Barry realizes that he's landed on the wrong Earth in his efforts to reach Earth-2.
As Kara helps him research, Barry realizes just how different this other Earth is and how limited his options for assistance are. Winn and James show up, Kara tells them that Barry is from another universe. Winn seems very dorkily excited about this news and tells Barry that Kara is an alien. Eventually, Barry explains the theory of the multiverse and tells them that he accidentally landed on their Earth and needs help to get home.
After Kara and Barry leave to get food, Winn comments on the fact that James is jealous of Barry, who seems to be bonding with Kara over their shared abilities. Back at CatCo, Cat tells Kara and Co. about the new, mysterious superhero in National City who is direct competition for Supergirl. Kara says he doesn't have to be competition, but when Cat says that maybe he's a sidekick, Barry decides to speak up on the Flash's behalf. This prompts Cat to utter what is definitely my favorite quote of the episode: "All four of you standing there doing nothing, you look like the attractive yet non-threatening, racially diverse cast of a CW show." Cat says that she needs a clear picture of the new hero and decides to give him a name. Much to Barry's dismay, and despite his protests (which result in this gem of a line: "The Flash? Sounds like someone whose only superpower is jumping out of an alley in a trench coat), she lands on the Blur.
After the boys leave, Cat compliments Kara on making James jealous by hanging out with Barry.
Meanwhile, Siobhan goes to ask her aunt for help. Her aunt already knows what she's going through and tells her that their family was cursed by a banshee. She tells Siobhan that the curse is triggered when someone wrongs her and she'll have to kill that person in order to stop it. If she doesn't, her scream will be come a weapon and she'll lose her soul. Siobhan, however, is more than happy to kill Kara and devices a plan free Livewire using her voice so that she to distract Supergirl long enough to get Kara unprotected.
When Kara gets news of Livewire's escape, she tells Cat that she should leave town but Cat refuses to run. She says that Supergirl saved her before and she'll be there to save her again. Kara goes to ask Barry to help her stop Livewire and protect Cat and the rest of National City. She promises that if he agrees to help her, they'll help him get back to his own Earth.
At the DEO, Barry is super excited about the lab. The agents, however, are a bit less thrilled by a random speedster. Barry explains who he is and agrees to help them track down Livewire.
Meanwhile, Siobhan explains her plan to Livewire and says that they can both get their targets if they work together. Livewire tells her that she needs a makeover and the two go off to work together.
Back in the lab, two much more likeable characters are also working together, much to the dismay of James. Lucy says that she knows how he feels and that if he's holding back from being Kara because of her, he shouldn't. Barry manages to track Livewire to the abandoned warehouse, and he and Kara race off to stop her.
Livewire is there waiting for them and Barry throws lightening at her, not realizing that this will only add to her power. He's knocked out for a while when she throws it back. Before Kara can use the sprinkler system to stop Livewire, Siobhan reveals her new villain persona, Silver Banshee, and the two villains decide to tag team her. Thankfully, Barry is back in action and he and Kara manage to generate enough wind to push the villains back long enough to escape.
Safely at CatCo, Kara is discouraged both with thier failed attempts to stop Livewire and her current status as public enemy number one. She explains what happened to him and Barry, having experienced a similar situation with Rainbow Raider, completely understands. He tells her that she needs to slow down and keep doing good and eventually the public will forgive her, just like they did him.
Of course, once Kara and Barry go back to DEO, Livewire decides to show up and confront Cat, with Siobhan in tow. Winn tells Siobhan that she should stop, that they can help her. Siobhan, however, is too far-gone. She and Livewire kidnap Cat in order to coax Supergirl and the Flash out for a fight.
Back at the lab, Barry tells Kara about Pied Piper and explains that they can use the same technology Cisco used to protect themselves from her scream. Livewire appears on the DEO screens and tells them to come out for a fight or she'll kill Cat.
Out on the street, Livewire and Silver Banshee wreak havoc as they wait for Supergirl and the Flash to show up. Once they show, Silver Banshee tries to shut them down with her voice but their new earbuds prevent her from doing much damage. Barry chases Livewire down while Kara manages to free Cat before getting punched by Siobhan. Unfortunately, Barry's earbuds do nothing to stop Livewire's electricity and she manages to temporarily incapacitate him.
Once she's reunited with Siobhan, who's currently battling Supergirl, Livewire decides to bring down a helicopter. Before the electricity reaches the helicopter, however, Kara takes the shock herself and ends up on the ground. Realizing that Supergirl just saved all of them, the citizens of National City ban together to protect her. Thankfully, before Livewire can start electrocuting people, the fire departement shows up to shuts them down, telling Supergirl that it as their turn to save her.
Back at CatCo, Kara tells Winn and James that Livewire and Silver Banshee are safely locked away in the new metahuman cells that Barry helped the police build. Kara asks Cat if they can go see Barry of and she reveals that she knew all along that Barry was the Flash because she "can spot the extraordinary pretending to be a nobody in [her] midst like that". Chyeah... okay.
Barry tells Kara that if they run together and she throws him at her fastest, he should be able to go fast enough to get back to his own Earth. Before they start, though, he tells her that she should speed things up with James because there's no point in taking things slow when two people really like each other. Finally, they hug and Kara launches Barry through the breach.
At Kara's apartment, James comes over to see if Barry made it home. Kara tells him that she wants to talk to him about infinite Earth's and tells him that if two Earth's can manage to vibrate at the same speed, that maybe there's a chance that they can be together. She then kisses him and the whole world let out a collective "Finally!"
James, however, doesn't react to the kiss. Instead, he turns and marches out the door like a zombie, along with everyone else in the building. It's revealed that they, and all of the citizens of National City, are being drawn to Non, who has apparently launched Myriad.
This crossover episode, while a little confusing at times, was pretty freaking great! Barry and Kara's personalities really complimented each other and I loved seeing Winn's obvious bro-crush on Barry throughout the episode! I'm looking forward to seeing what happens next in both universes!
What was your favorite part? Are you hoping for more Flash/Supergirl collaborations? Tell us in the comments!