Supergirl-2015-55621430e3b39 Supergirl/Flash Crossover Character

This article is about a character from CBS's Supergirl and appeared in the crossover between the two shows. For a complete article on on this character see Supergirl Character

"Worlds Finest" is the eighteenth episode of the first season of Supergirl. It aired on March 28, 2016.

Episode Synopsis

Kara gains a new ally when the Flash arrives from an alternate universe and helps her fight the Silver Banshee and Livewire in exchange for her helping him return home.


Kara Danvers, aka "Supergirl", is blasted out of CatCo's Plaza window by Siobhan due to a powerful sonic scream. This reason behind it being that Siobhan hates Kara for ruining her life. A curse placed on the females of her bloodline, from a long time ago in Ireland, has made sure that until she kills the one she loathes she will remain cursed by a banshee and lose herself in the process. As Kara falls from the window, a red streak runs up the side of the building and catches her.

This red blur turns out to be Barry Allen, from earth one. He seems horrified that Kara's clothes are on fire, but the Kryptonian doesn't seem phased at all, merely putting them out with a few quick pats. Kara, confused and disoriented, flies away but Barry pursues until she lands again. She apoligizes for leaving so abruptly, and asks who he is. This time it's his turn to be surprised, and he asks her if she has heard of him. To this she replies no, and when he goes on to name a few other of his superhero friends and enemies she shrugs and apologetically says no. He notes how he's never heard of her either and comes to the conclusion that he must have traveled to her universe by accident. Kara agrees to help him figure out how to get back to his own earth.

Back in National City, Kara introdues Winn and James to Barry who explains to them the Theory of the Multiverse. Winn seems to pick it up especially quickly. Barry suggests that Kara and his universe converged for a moment and he must have run through the void at the right time- though not on purpose. To prove his speed to the three, he rushes off for a second but when he returns everyone is holding an ice cream cone. After Kara and Barry exit the room, Winn teases James about Kara hanging around a male that isn't the latter. James denies being jealous.

At CatCo Plaza, the owner, Cat Grant, berates Kara for still being alive after being tossed out the window. She informs her that Supergirl has competition seeing as there is a new hero in town- whom she dubs "The Blur" much to Barry's horror. Cat insisted that it sounded more mysterious than his eager suggestion of "The Flash." She tells James to find a better picture of "The Blur." Kara is also quick to tell her boss that Supergirl and The Flash/The Blur don't have to be rivals but more like partners. 

Meanwhile, Siobhan has released Livewire from her cage at the D.E.O in hopes of a supervillain team up, acting on the saying "the enemy of my enemy is my friend." Livewire seeks to kill both Supergirl and Cat Grant while Siobhan wishes to kill Kara, whom is under the protection of both the two woman. When Kara gets a call that Livewire has escaped she immediatley warns Cat that she must evacuate the premises. Cat refuses, saying that she's beat vengeful employees before and that she'll do it again. Kara, not assured in the slightest, hurries to Barry to ask for his help.

Once Barry and Kara have made their way to D.E.O headquarters and persuaded Lucy to let him stay, the two start talking about the similarites of their villains. He also mentions to Lucy that he fights criminals both during the day and at night where he's from, because he is a CSI. They allow him to use Alex's- Kara's human sister- lab.

Livewire is drawn to an abandoned warehouse and to her delight- finds a full case of beer. Siobhan convinces Livewire to help her teamup against Supergirl and Cat to get their revenge. Livewire also points out that Siobhan will need a makeover if she's going to play the part.

James, back at the D.E.O looks at Kara and Barry talking with envy, but is soon convinced by Lucy that he needs to fight for her- regardless of whatever they had in the past.

Barry and Kara track Livewire to the abandoned warehouse- Barry points out that villains seem to love hiding out around there. Barry wants to make a plan, but Kara rushes in immediatley and reaches the destination first. Barry waves that off by saying that he circled the perimeter before coming in. When Livewire appears from the shadows, Barry runs circles around her, building up enough energy to throw a lightning bolt. He'd hoped that the energy would be too much and she would overload, but instead it only gave the electric antagonist a charge. She blasts Barry backwards into a wall.

Kara, about to take the free moment to melt a sprinkler over Livewire's head is caught off gaurd but Siobhan's sonic scream- now dressed as a supervillain would complete with creepy makeup. She dubs herself "Silver Banshee." Barry and Kara both realize they need to strategically retreat and regroup, so they rush off.

Kara and Bara share a moment back in National City, where she admits the city doesn't really trust Supergirl at the moment because of a mistake she made when under the influence of something evil. She fears that the city will never love her again but Barry comforts her by recalling how that happened to him once and after some time passed, people moved on.

Livewire and Silver Banshee kidnap Cat from her building later that day (the second whom Winn pleads with only to be blasted backwards), and Barry and Kara receieve a message at the D.E.O from the two. They are told to meet at National City Park if they don't want Cat's blood on their hands. Kara tells Barry that this is her fight, but Barry insists on helping. Cat, handcuffed to a bench in the park, begs the supervillains to spare her for her children, who will be without a mother if she dies.

Meanwhile, Barry creates special earplugs that will mute Silver Banshee's powerful scream. Just as Cat is about to be electrocuted, Barry and Kara alive. Barry cracks a joke that they should all settle this like women- because they're all female except for him. Silver Banshee screams at them but to no avail due to the sonic cancelling earplugs. Liveware travels up to a rooftop where Barry pursues but is eventually knocked out by one of her powerful blasts.

Kara releases Cat from the bench but is knocked down by Silver Banshee. Livewire returns to the scene just in time to aim her electricity at a helicopter passing by. Kara flies up and absorbs the shock but collapses back to the ground in pain. The people in the park see this and are filled with compassion because they see that Supergirl just saved their lives. They gather around Kara and tell the villainous duo that they're going to protect Supergirl. Just as Livewire is about to blast them a stream of water hits her and she misses- only to hit her partner, Silver Banshee. The water came from the fire department who were helping Supergirl out.

Barry helps the police create cells, much like the Pipeline under S.T.A.R. Labs to hold Silver Banshee and Livewire. Cat also tells Kara that she knew all along Barry was The Flash- her "cousin" coming to town at the same time as The Flash was an awfully large coincidence. She laments on how she's good at seeing people who hide in plain sight.

Back in the desert, Kara helps "throw" Barry back into his earth by combining their speeds. He dissapears through a blue portal, presumably back to earth one.

Back at Kara's apartment, James and her talk about being together and share a kiss. His reaction is blank, and Kara realizes that people everywhere are walking out into the street like mindless zombies. One of Non's goons reports that "Myriad" is underway.


  • The episode's title is "Worlds Finest" without an apostrophe because it means of more than one world. "World's Finest" with an apotrophe would limit the finest to one world- instead of multiple.
  • Winn also refers Barry and Kara as the "Dynamic Duo", which is a reference to Batman and Robin.
  • Green Arrow, Laurel Lance, The Atom, Firestorm, Zoom, Cisco Ramon, Caitlin Snow, Harrison Wells, Blackout, Pied Piper and S.T.A.R. Labs are all mentioned by Barry within the span of the episode.
  • Cat Grant mentioned The CW which airs The Flash on Tuesdays.
  • This episode actually takes place after Flash Back in chronological order, even though this episode aired a day before the other. In the episode Versus Zoom Barry goes through a portal as a result of running too fast and comes out a moment later asking how long he'd been gone. This episode took place in that time period.

Episode Gallery

Supergirl 1x18 Promo "Worlds Finest" (HD) The Flash Crossover00:31

Supergirl 1x18 Promo "Worlds Finest" (HD) The Flash Crossover

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