In "Worlds Finest," Barry Allen accidentally flashed over from Earth One (which makes Kara's earth... Earth Three? Earth Zero?) just in time to save the Maiden of Might from an unconscious fall out of a skyscraper. That chance meeting led to a gem of an episode in which Barry and Kara join forces to take down a pair of really, really disgruntled former employees. Some of it didn't make sense. Fuzzy science, muddled motivations, take your pick. But you know what? It didn't matter. Not a lick. When something is this fun, this buoyant and jubilant and even a little bit earnest, one can forgive a multitude of sins.
The best part, though, is that there weren't that many sins. It's nearly impossible, given the timing, to discuss this episode without thinking of that big movie that opened this weekend, but whatever your opinion of "the greatest gladiator match in the history of the world," this is a collision of DC titans that worked on all levels. It also worked commercially -- it's hard to imagine that fans of "Supergirl" unfamiliar with "The Flash" won't want to check out that CW show and its "attractive yet non-threatening racially diverse cast," as Cat so aptly put it, and the same is likely true of "Flash" fans who hadn't caught "Supergirl" before.
But what worked best is what also works in the "Flash"/"Arrow" crossover episodes: their differences push great new things out into the air, and their similarities grow even stronger. Oliver Queen is never more likable than when he's hanging with Barry. Barry gets pulled to earth a bit by Team Arrow. And Supergirl, who's had a very rough go of it lately, finally gets a confidant who has been there, and an ice cream cone, to boot.
The plot -- which again, works, but also feels utterly beside the point -- begins with the unlocking of Siobhan's curse (as explained to her by her aunt, the great Bebe Glaser, who uses an Irish accent to sell useless quartz to Muggles). Pissed at the world, and especially at Cat and Kara, Siobhan storms out of the DEO, pushes Winn away for only the first of what seems like many times in this episode, and runs right into the warm embrace of villainy. When her aunt tells her that to stop her family's curse from tormenting her, she'll need to kill the person she hates, she doesn't even blink. That's a sure sign you've got the makings of a good villain. Then she gets herself a partner -- LiveWire, from way back in episode four -- and a new look, and wreaks some havoc.
That's where Mr. Barry Allen comes in. When a pre-Banshee'd Siobhan blows Kara out a window and Barry catches her, the pair discover that whoa, they both have superpowers, and oh yeah, Barry's from another earth. Kara quickly introduces him to the gang -- Winn is immediately sciences-buddies with Barry, while James is less than thrilled that there's a cute speedster in their midst -- and begins helping him figure out how to get back. They're interrupted by the news that LiveWire's escaped, and Cat's faith in Supergirl means she's not going into hiding, so there's bound to be trouble. That means we're due for a Flash-Supergirl team-up, and it's pretty darn great.
Jokes about who's faster? Check. Over-enthusiastic super shoulder-squeeze? Check. Flash theme playing while Barry zips around? Check. Lots of clever banter, some earnest pep talks, new gadgets, a more ethical prison, and plenty of nicknames? Quadruple check. Supergirl blows ice-breath at the evil duo and The Flash fans it with his crazy fast arms. Barry tries to attack LiveWire with electricity and accidentally charges her up. They soar. They punch. They wink. It's wonderful.
It all hangs on the big lingering story-arc -- Kara's brush with red Kryptonite and its transformation of her into someone much darker and less kind -- and her fear that people will never want her to help them again. It's a great turn for a story so deeply rooted in optimism and empathy, and given that "The Flash" has tackled similar themes, though not as extensively, it makes sense as a central through-line. Of course Barry will be in Kara's corner. Of course when she's in danger, the people she's saved will step up to protect her right back. Kindness and courage won't always win the day, but when you've got Barry and Kara, it's a pretty good bet that they will.
If the episode had one off-note, it's actually the result of all that goodness. The Kara Danvers-Barry Allen chemistry is about a thousand times more interesting than any other pairing that "Supergirl" has teased thus far. That's not a slight against any of the performers involved, but as loyal, smart, and entertaining as James and Winn are (and Winn in particular, who has gotten so much more engaging now that he's not pining after Kara), they're no match for Kara Danvers. Mehcad Brooks and Jeremy Jordan are very fine performers, but Melissa Benoist is clearly living a dream, and her infectious warmth is unmatched (though Calista Flockhart, David Harewood, and especially Chyler Leigh come close, at least in their scenes with her). In "Worlds Finest," she finally meets her match in terms of star power, charisma, and honesty, and the only downside of Grant Gustin's appearance is that it highlights exactly how outclassed all these other schmucks are. If Supergirl must date, I hope she finds a portal to Earth One.
Alas, it's not to be. Barry gives Kara some relationship advice (which, if you watch "The Flash," you'll know is a bit of a pot-kettle situation) and she goes off to finally confront James about the nature of their relationship. Kara might not have great timing, but her evil uncle sure does, as Non chooses that exact moment to engage Myriad, prepping us for next week's big episode.
Oh, and about that Supergirl/Flash footrace. Who won?
Answer: it's a tie. And the real moral of the story is that as fast as they are separately, they're fast enough together to rip a hole in the universe. As the two race, Kara gives Barry a push -- Barry's idea, don't worry, there's no unsportsmanlike conduct -- and the added boost makes it possible for Barry to zip back to Earth One. At least, that's where he's supposed to have gone.
The point isn't the winner, anyhow. That's lucky, because there isn't one. The point is that the quick race embodies the spirit of fun that fills the whole episode. It's about the joy of helping, of making friends, of running really fast and flying really high, and about the pleasure of watching something that the people who made it clearly and unabashedly loved. The teams of "Supergirl" and "The Flash" clearly had a blast making this episode, and so it was a blast to watch. Would everything were so simple.