Crossover episode with The Flash which sees The Flash's dimension-traveling abilities taking him to Supergirl's universe. While Kara tries to help Barry find a way home, Siobhan uses her new powers to break out Livewire so they can take revenge on Supergirl and Cat Grant. A rare modern-day example of a cross-network crossover, as at the time Supergirl aired on CBS and The Flash airs on The CW.
Tropes in this episode:
- Abandoned Warehouse: Barry finds out that Livewire is hiding out in one, and acknowledges that villains in Supergirl's universe like to hide out in these like in his universe.Barry: I see bad guys love their abandoned warehouses on your Earth, too, huh?
- Adaptational Intelligence: Barry Allen is by no means stupid, but without his support Team Flash behind him, he manages to cover for at least Cisco Ramon without him being present. Some of these, like the noise-cancellation earplugs and ideas on how to improve National City jails to be able to hold metahumans, could be rudimentary knowledge that is extrapolated upon by the DEO to create the technology, but Barry is also shown to be a skilled coder, able to create an algorithm to track Livewire, in a feat that Cisco would usually handle. It's really not a case of Barry being more intelligent in the adaptation as it is a case of him actually getting to show off his intelligence this time around, as the support cast that normally fills that role is not present.
- Adapted Out: It has been confirmed that none of the members of Team Flash exist in this universe, although them having different names is possible.note As for the members of Team Arrow, if any of them exist in this universe they haven't assumed their superhero identities.
- Affably Evil: Siobhan's Aunt Sinead who casually confesses to murdering her husband and encourages her to do the same to Kara.
- Ain't Too Proud to Beg: Cat, though she does it for her sons' sakes, not herself.
- Amicable Exes: In a change from only a couple of episodes previous, Lucy is comfortable that she and James were never meant to be and even encourages him to pursue a relationship with Kara.
- Arbitrary Skepticism: Kara admits it's hard to believe Barry is from another universe since she's an alien and has an easier time understanding another planet. Winn on the other hand immediately accepts it when Kara introduces him.
- Barry is equally flabbergasted to find out Kara is from another planet.
- Big Damn Heroes:
- Barry makes his Big Entrance by saving a falling Kara. He doesn't find out until afterward that his assistance was entirely unnecessary. Although it was helpful in maintaining Supergirl's secret identity.
- The firefighters that Supergirl assisted in the beginning of "Falling" return the favor when they douse Livewire with water, taking down both Livewire and Silver Banshee, thus saving Supergirl and the civilians trying to protect her.
- Big Damn Kiss: Kara and James share one near the end of the episode.
- Big Eater:
- Both Kara and Barry are capable of eating plenty of donuts thanks to their super metabolism.Barry: Speaking of food, I need to eat like ten thousand calories a day...
Wynn: Oh, you definitely met the right girl.
Kara: Do you like donuts?
Barry: Who doesn't like donuts? - Cat appears prepared to eat an entire box of luxe cupcakes on her own.Cat: [grabbing Kara's wrist] These are mine.
- Both Kara and Barry are capable of eating plenty of donuts thanks to their super metabolism.
- Big "YES!": Kara lets out an epic example of this when Barry delivers ice cream at super speed. The scene intentionally makes it ambiguous as to whether Kara is reacting to seeing Barry do an amazing feat at superspeed ... or the ice cream (a delicacy that had her literally jumping for joy in a previous episode).
- Bilingual Bonus: According to the commentary, when Siobhan marches into CatCo's office in the prologue we can hear chanting of "mharú" in the background, the Irish word for "kill".
- Birds of a Feather: Barry and Kara become fast friends, bonding over their similarly sunny personalities and later commiserating with each other over how the public can often sour on superheroes.
- Buffy Speak: When Barry whips up the earbuds, he says they're protection against Banshee's "yell-y voice."
- Cat also mentions it's not the first time employees of hers got all "revenge-y."
- The Bus Came Back: Livewire returns after she was last seen being imprisoned by the DEO in her debut episode.
- Call-Back:
- Referencing her origin, Livewire fires a blast at a helicopter because she now has a hate on for the things.
- Barry's previous experience fighting metahumans informs his strategies against Livewire and Silver Banshee. Sometimes it works, as in the case of his enhanced earplugs. Sometimes it doesn't, in the case of him attempting to overload Livewire like he did Blackout in "Power Outage".
- Barry creates an algorithm to track metahumans, like his Earth-2 counterpart.
- Siobhan rejects Kara's offer of help by saying she's "good as is". Livewire used those same words during her own Redemption Rejection.
- Kara tosses Barry to the dimension breach the same way he tossed Eobard Thawne in a recent episode of his own show.
- Barry tries to get a picture with Kara's spaceship.
- Barry took Oliver's lesson about scouting the situation to heart (which may be why Kara arrived at the Abandoned Warehouse before him).
- The Fire Chief, helping Kara up after dowsing the villains, is lit from behind while reaching for her, like Superman was when he helped Kara out of her pod in the Pilot.
- Celebrity Paradox:
- Averted. While Cat mentions The CW, the network that airs The Flash, she and the other characters clearly don't know who he or the other Arrowverse characters are, meaning his show and its sister shows do not exist as TV shows on Kara's world.
- Played straight when Barry confirms that Mariah Carey also exists in the Arrowverse. Wentworth Miller, who plays Leonard Snart aka Captain Cold in his universe, was Mariah's Love Interest in two of her (hit) music
videos.
- Chekhov's Gunman: The firefighters that Kara rescued before her Red Kryptonite rampage are the ones who help her defeat Livewire and Silver Banshee.
- Continuity Cavalcade: Barry recaps pretty much every major moment from his own show over the course of the episode.
- Crossover:
- Barry Allen ends up in Supergirl's world due to dimension-hopping. This was the first of what would be a regular series of crossover events between the two shows (often combined with the other Arrowverse series).
- A snippet of The Flash's theme plays when Barry runs out and returns with ice cream.
- From a real world perspective, this was a rare network-crossover, as at the time Supergirl was airing on CBS, not The CW.
- Cursed with Awesome: Siobhan ends up accepting her Hereditary Curse.Silver Banshee: All my life I thought I was cursed. But now I see I was cursed for the better.
- Dark Action Girl: Both Livewire and Silver Banshee.
- Double-Meaning Title: The title refers to both Kara and Barry, The Heroes of their respective worlds.
- Dramatic Irony: Played for Laughs. When Cat tells Kara that she can "spot the extraordinary pretending to be ordinary in [her] midst" easily, she is completely unaware that she is talking to Supergirlnote . James even laughs under his breath after Cat leaves.
- Enemy Mine: Livewire and Silver Banshee unite over their common hatred of Cat.
- Even Evil Has Standards: When bystanders come between Supergirl and the villains, Livewire has no problems trying to kill them, but Silver Banshee hesitates and doesn't attack, suggesting that she's not as evil as her partner. (At least not yet.)
- Fake Nationality: Played with In-Universe, as while Siobhan's aunt is ethnically Irish, she's American, but puts on an over the top Irish accent to sell magical trinkets.
- Fighting Irish: Silver Banshee is of Irish ancestry, is an unpleasant person in general, and draws her powers from a banshee's curse.
- Foreshadowing:
- Flash namedrops the Pied Piper when explaining how he knows how to counter sound-based villains. Non pulls a Pied Piper trick of his own at the end.
- Lucy accuses Livewire of having something to do with five deaths caused by electrical imbalances in the brain. The end seems to suggest Myriad was actually responsible, presumably from Non testing the device on a few people before the larger, city-wide implementation.
- While Barry is explaining the multiverse, he mentions a hypothetical example of a world where Nazis won World War II (see Godwin's Law of Time Travel below). Barry and Kara would later actually visit such a world in the Crisis on Earth-X crossover.
- Funny Background Event: As Barry is trying to convince Cat to use The Flash moniker, James and Winn are trying to shush him from arguing with her.
- Godwin's Law of Time Travel: Invoked by Barry when he uses the "Hitler won WWII" example for one of his hypothetical alternate Earths.
- Green-Eyed Epiphany: James starts to realize how he feels for Kara after seeing her and Barry immediately bond.
- Heel–Face Door-Slam: Winn tries to get Siobhan to stop, and it looks like it might work, only for her to decide she likes being Silver Banshee. Cat begs Livewire not to kill her because of her children; this actually has an effect on Leslie, but before we can see if anything comes of it, Flash and Supergirl arrive.
- Hereditary Curse: Siobhan's powers originate from one, due to an ancestor who got on the wrong side of a banshee. Whenever a woman in the Smythe family is wronged (which is often due to the fact that they are also cursed to have unlikable personalities), they are granted banshee powers until the one who wronged them is dead. Refuse to take their revenge, and the banshee spirit drives them insane.
- Heroic Bystander: After watching Supergirl get hit by a bolt from Livewire to save a helicopter, a whole crowd of civilians runs to shield the wounded hero from the villainesses, despite justifiable terror.
- Hero of Another Story: Barry Allen aka The Flash, a superhero who comes from an Alternate Universe who headlines his own show from another network.
- Hoist by His Own Petard: Silver Banshee broke out Livewire so she could ensure the defeat of Supergirl by tipping the odds in her favor. But when Livewire was shorted out, she shocked Silver Banshee, taking her down too. Her intended back-up wound up causing her defeat and capture.
- Humanizing Tears: The normally proud Cat tearfully begs for her life.
Not for herself, but for her sons to still have a mother. - "I Know You're in There Somewhere" Fight: From Winn to Silver Banshee. It doesn't work.
- In Spite of a Nail: Central City does exist in this universe, but there's no S.T.A.R. Labs or any counterparts of Team Flash.
- Irony: Acknowledged by Barry, a speedster, giving Kara the advice to slow down in her endeavors to earn National City's forgiveness.
- It Will Never Catch On: When Cat is trying to pitch a name for the new "mystery speedster", Barry tries to suggest calling him The Flash. Cat shuts the idea down on the basis of it sounding like a streaker.
- Jerkass: All the women of the Smythe family, which ensures that their Hereditary Curse will inevitably kick in.
- Kill It with Water: How Livewire and Silver Banshee are defeated, courtesy of some Badass Bystander firefighters with a hose.
- The Knights Who Say "Squee!":
- Barry is simply ecstatic to be in a universe where aliens exist and even tries to get a picture with Kara's spaceship. Likewise, Winn is thrilled to have another superhero in the mix, particularly one who's a fellow nerd. Finally, Kara geeks out a bit about Barry's super-powers (particularly when he uses it to fetch ice cream cones) and the fact that they make him a Big Eater like her.
- On the flip side, Winn becomes Barry's number one fan in record time.
- Leaning on the Fourth Wall: Cat makes a comment about how Barry, Kara, James and Winn look like the cast of a CW show.
- Leeroy Jenkins: While Winn and Barry suggest building another industrial capacitor to use against Livewire, Kara wants to fight them immediately (with no specific plans or countermeasures) before they hurt any more people. This is due to Kara's desperate attempts to win back the respect of National City.
- Locked Out of the Loop: Due to coming from very distantly separated universes (Earth-1 and Earth-38, respectively), Flash and Supergirl have no clue who the other is nor have they heard of their allies or rogues.
- Man on Fire: Barry accidentally sets Kara's shirt on fire when he saves her. He attempts to put it out, then stops because the fire is on her chest and he doesn't want to grope her. Then he notices that the flames don't seem to bother her anyway.
- Maybe Magic, Maybe Mundane: Siobhan's Silver Banshee look. We do not know if she actually transformed or if it's just costume and makeup.
- Meaningful Echo: "I'm (The Flash/Supergirl)." "You're who now?"
- Mind-Control Device: Project Myriad evidently allows for mass control of humans. Non uses it to compel the entirety of National City into marching towards some unknown purpose, and his comments imply it can work on a global scale.
- Moment Killer: Kara's Big Damn Kiss just happens to fall right on the moment that Non decides to test Project Myriad.
- Mood Whiplash: A fun episode involving a major crossover culminates in Kara finally kissing James... and then the entire population of the city is taken over by Non, setting up a dramatic cliffhanger.
- Muggles Do It Better: Despite two superheroes teaming up, it's ultimately the non-powered firefighters who defeat the two supervillains and save the day.
- The Multiverse: While The Flash had already established that multiple versions of Earth were considered part of the Arrowverse, this episode brings the Earth of Supergirl within that setting (although a previous '"Flash'' episode did show an image of Supergirl, foreshadowing the crossover). It would have been impossible to simply have them set on the same Earth given Superman's extensive backstory here and implied nonexistence in the other world.Barry: So imagine there are multiple versions of Earth: One where the Nazis won World War II; One where President Kennedy wasn't assassinated...
Winn: One where all of us are evil?
Barry: Been there. It sucks.- There isn't any evidence that aliens don't exist on Flash's Earth; there's just not been a corroborated sighting. Yet.
- The only major difference seems to be the existence of characters (as heroes) and Supergirl/Superman (and other aliens) on their respective worlds.
- Mythology Gag:
- World's Finest is the comic published by DC that features two or more DC heroes teaming up temporarily.
- The poster for the crossover shows Supergirl and the Flash racing, as an homage to the first comic book race of Superman and the Flash back in 1967. And just like in the comics, the episode has the Flash and Supergirl (replacing Superman) in a friendly competition to determine who is faster, with no clear resolution.
- At the DEO, Siobhan is examined by Dr Hamilton. Whether she's related to the Dr Emil Hamilton who figures heavily in Superman's mythos, is this universe's version of him or the name is simply a nod remains to be seen.
- Lucy wants to call Barry Speedy.
- Cat wants to call Barry the Blur, and this is even shown on a television in Cat's office later as his official name on Supergirl's Earth.
- Many superheroes present in the Arrowverse but not here are mentioned in this universe for the first time, such as Green Arrow, Black Canary, Firestorm, and The Atom. Barry also mentions Zoom, the current Big Bad of his series.
- Additionally at the end Barry calls Kara the 'Girl of Steel', and she returns the favour by referring to him as the 'Scarlet Speedster.'
- Wynn refers to Kara and Barry as "The Dynamic Duo."
- Nice Job Fixing It, Villain: When Livewire tries to electro-shock the helicopter, Supergirl jumps in front without hesitating. This makes her a hero again in the eyes of the people of National City.
- Nice Guy: Barry, of course. Cat claims this was a factor for how she deduced he was the Flash.Cat: He was so unfailingly charming and nice, he either had to be a superhero or a Mormon.
- No-Sell:
- The Flash attempting to knock Livewire out via lightning throwing only powers her up.
- The Flash whips up some earplugs that protect him and Supergirl from Silver Banshee's scream. So then she turns her scream to the crowd.
- Project Myriad controls the minds of humans, but does nothing to Kryptonians.
- The One Guy: Barry lampshades his status as the only male during the climactic battle.The Flash: What do you say we step away from the nice lady, settle this like women... [off Supergirl's look] What? There's more of you guys here than me.
- Open Secret: It would appear that the DEO doesn't seem to care if its "secret base" is secret anymore. Winn and James appear able to come and go at will, and Kara has no problem bringing Barry into the base before Lucy is even aware of his presence (though his Super-Speed may have helped with that). But the icing on the cake is that Winn is able to bring Siobhan into the base; even though her presence isn't unusual, as the DEO would have a vested interest in examining her, it does kind of blow any secrets Winn might be carrying about his involvement with the organization.
- Operation: Jealousy: Invoked by Cat, who suggests that Kara make herself unavailable if she wants to attract James. Though she doesn't do it intentionally, it works.
-
Out of Order: Due to the difficulty of coordinating schedules between two networks, we didn't see Barry's side of the universe hop until "Versus Zoom", a day after the first season of Supergirl ended. - The Paragon: Barry is one for Kara in this episode. Cat even hangs a lampshade when she reveals that she knows he's the Flash.
- Platonic Life-Partners: Kara and Barry.
- Pun-Based Title: The episode's title is a pun on the World's Finest comic that centers on the fact that Supergirl and the Flash come from different universes.
- A Pupil of Mine Until He Turned to Evil: Both Villains of the Week were protégées of Cat Grant at some point, and team up to take revenge on her and Kara. Lampshaded by Cat.
- The Real Heroes: In the end, it's neither Kara nor Barry who end up defeating Livewire and Silver Banshee, but ordinary firemen.
- Rescued from the Scrappy Heap: In universe, seeing Supergirl take Livewire's blast in order to protect a police helicopter causes the crowd to regain their faith in her heroism to the point that they rush forward to protect her from Livewire and Silver Banshee.
- Rule of Cute: There really wasn't any logical reason for Barry to make a lightning-fast ice cream run. But it still resulted in the episode's signature cute moment.
- Science Hero: The Flash, natch. Beyond his speed, Barry Allen's greatest asset compared to the practically invulnerable Kara is his experience and knowledge. In the episode, he is able to whip up both a tracking algorithm for Livewire and a countermeasure for Silver Banshee thanks to having fought similarly powered foes in the past. At the end of the episode, it's mentioned that he's provided the National City Police Department information on how to contain and imprison superpowered beings, allowing the normal justice system to deal with them, just as has begun to happen on his Earth.
- Shipper on Deck: Cat spends most of the episode trying to get Kara to get together with James. Even Barry gets in on the action, and Lucy works on James from the other side. Winn, on the other hand, appears to push for Barry x Kara, simply because he's entertained by James's jealous reactions.
- Ship Tease: Barry and Kara get close with each other, but nothing comes of it due to her feelings for James and Barry trying to return to his Earth.
- Shout-Out: To Mariah Carey and The Three Musketeers. Barry double-checks that the book exists on this Earth.
- Barry also takes time to give shoutouts to characters from Arrow, Legends of Tomorrow and of course his own show.
- Sickeningly Sweethearts: A non-romantic version between Kara and Barry. The two are so positive and seem to enjoy each other's company so much that it actually makes James jealous.
- Significant Wardrobe Shift: Signifying her new role as director of the organization, Lucy has taken to wearing the standard DEO uniform.
- Spoiler Opening: The Previously on… and the guest stars line-up in the OBB both spoil Non's return.
- Super-Strength: Silver Banshee somehow gets this in addition to her trademark sonic scream; at one point she is inexplicably able to send Supergirl flying with a single punch.
- Take That!:
- The production team behind Supergirl is clearly poking fun at the expense of the Arrowverse and the network which it airs. Doubles as Self-Deprecation, since the shows' teams are run by the same people.Cat: All four of you standing there, doing nothing. You look like the attractive, yet non-threatening racially diverse cast of a CW show.
- Livewire likens her and Siobhan's Villain Team-Up to "an evil Taylor Swift squad".
- The production team behind Supergirl is clearly poking fun at the expense of the Arrowverse and the network which it airs. Doubles as Self-Deprecation, since the shows' teams are run by the same people.
- Taking the Bullet: Supergirl takes an electric blast aimed at a helicopter, which endears her to the people once more.
- Today, X. Tomorrow, the World!: After mass controlling the city, Non says, "First National City, and then the Earth itself will belong to us."
- Too Fast to Stop: Barry accidentally crosses to another dimension, grabs the falling Kara and drops her in a field in the middle of nowhere because he underestimates his speed with the tachyon device.
- Trailers Always Lie: The first trailer for the episode show the Flash and Supergirl encountering each other in an alleyway at night. No such scene occurs in the episode since the trailer was composed of stock footage from their respective shows.
- Trailers Always Spoil:
- Set photos released several weeks before this episode's air date reveal Siobhan Smythe—first introduced as an ordinary human in "Truth, Justice and the American Way"—has now become the supervillain Silver Banshee.
- The two moments most cited by critics and fans as highlight of the episode — Kara reacting to the ice cream and Cat's metafictional CW joke — were released several days before the episode aired as promo clips.
- Trapped in Another World: Barry Allen is stuck in this world because the tachyon device made him go too fast that he accidentally traveled to this dimension, with Kara helping him find his way home.
- Villain Team-Up: Silver Banshee allies herself with Livewire.Livewire: Like an evil Taylor Swift squad?
- Wham Episode: This episode officially integrates the show into the Arrowverse.
- Wham Shot: Silver Banshee makes Supergirl's ears bleed.
- While it is still a W/S, Superman (and by extension, Supergirl) can be harmed by magic, the basis for Silver Banshee's power/curse.
