‘Supergirl’ Episode 18 Recap — The Flash Comes To National City For Crossover Episode

When Siobhan Smythe first showed evidence that she would soon reveal herself to be Silver Banshee, the viewers of last week’s Supergirl saw what it was that would lead to The Flash appearing in a crossover episode of Supergirl to help protect Central City. With Martian Manhunter/Hank Henshaw and Kara’s sister Alex Danvers forced to be fugitives on the run as they look for Supergirl’s adoptive Earth dad — and Winn witnessing his crush Siobhan/Banshee demonstrating her hypersonic scream capabilities — the emotions from the DC Comics-based CBS superhero drama were all over the board.

This week, when the charming and handsome metahuman Barry Allen shows up, James Olsen begins to show signs of jealousy, and Kara spends the episode trying to decide what to do with her feelings about James Olsen. LiveWire is back, Silver Banshee is in full force, and metahumans and the multiverse theory are introduced to Supergirl. And since The Flash lists almost every significant DC character from the CW’s “Arrowverse” (Arrow, The Flash, and DC’s Legends of Tomorrow), there is now potential for Supergirl to appear on the CW, or for other characters from the Arrowverse to appear on CBS.

Episode Recap

As the episode began, Siobhan was being looked at by the DEO after miraculously surviving a normally fatal fall by using her voice. All the DEO could determine was that Siobhan was a human but she somehow emitted this supersonic frequency when she screamed. While at the DEO headquarters, Siobhan overheard Livewire saying how much she hated Cat Grant and Supergirl, so she later used her supersonic screaming ability to break Livewire out of the DEO prison.

However, before she devises that specific plan, she goes to the CatoCo offices and demonstrates her new vocal abilities by blasting Kara Danvers out of the window. The Flash, who is here by accident, catches the falling Kara Danvers, assuming she is an average human. Even though he is here by accident, he will have to help Supergirl defeat the team of Silver Bashee and Livewire before Kara can help him return to his own universe.

Early in the episode, Cat offers unsolicited advice to Kara about how she can get James to want her. What ultimately gets James to admit his feelings for Kara is how jealous he gets when The Flash clearly impresses Supergirl. While training to improve his speed in preparation to take on Zoom, The Flash accidentally transported himself from his universe to Kara’s. He explains the multiverse theory to Kara, James and Winn, which they all accept without question. Supergirl promises to help The Flash get back to his own universe, but only after he helps her save Cat from Silver Banshee and Livewire.


They fully established that The Flash and Supergirl were from two separate universes. Supergirl had no prior knowledge of The Flash, Green Arrow, The Atom, Black Canary, Zoom or anyone from any of the CW shows. Flash had never heard of Supergirl, but was fascinated by the fact that she was a legitimate contest for him in the speed department. When Kara, Barry, James, and Winn stood in front of Cat Grant, she delivered the best crossover line of the episode.

“All four of you standing there doing nothing: you look like the attractive-yet-not-threatening racially diverse cast of a CW show.”

So, to sum it all up: The Flash and Supergirl were able to defeat Livewire and Silver Banshee, but only with the help of humanity (the fire department). National City loves Supergil again, and the two metahuman villains are being held by the National City Police Department, not the DEO. Supergirl used her super-speed and super-strength to help boost The Flash back to his own universe, and James Olsen all-but-admitted to Kara how he felt.

As the episode ended, however, Non was shown, and it was confirmed that “Myriad” was in effect. And it went into effect just as Kara kissed James. Before he could respond to Kara’s advances, all of the humans of National City were being drawn somewhere, mindlessly. Still, nothing more was explained about Myriad or about James’ feelings for Kara. More of that will come next week, presumably.

Where To Watch

CBS airs Supergirl on Monday nights at 8/7 p.m. Central. Replays of the most recent episode of Supergirl are available to stream on-demand at CBS.com.

[Image via DC Comics]