"Worlds Finest" is the eighteenth episode of the first season of Supergirl. It aired on March 28, 2016. It acts as a crossover between Supergirl and The Flash.


Kara gains a new ally when the lightning-fast superhero The Flash suddenly appears from an alternate universe and helps Kara battle Siobhan, aka Silver Banshee, and Livewire in exchange for her help in finding a way to return him home.[1]

Behind the scenes

  • The episode's title is a reference to the World's Finest comics, which would have Superman and Batman crossover.
    • However, since the Flash and Supergirl come from different worlds, the title is spelled with plural, rather than possessive.
  • The promotional poster released for the episode is a reference to the cover of Superman #199, in which The Flash crossed over to verse Superman.
  • Winn refers to himself and Barry as the "dynamic duo", a moniker frequently used to describe Batman and Robin.
  • Cat refers to James, Barry, Winn and Kara as the "the attractive yet non-threatening, racially diverse cast of a CW show". This is a reference to traits frequently noted by media regarding The Flash.
  • Barry references a number of existing alternate universes. He mentions a world where the Nazis won WWII and a world where everyone is evil versions of themselves. He mentions having been to the latter, presumably referring to Earth Two, on which Caitlin, Ronnie and Cisco's doppelgängers are all villains.
  • Cat decides to nickname The Flash "The Blur", referencing a name given to Clark Kent on Smallville.
  • Siobhan's aunt, Sinead, refers to her customers as "Muggles", referencing a term frequently used in the Harry Potter series.
  • Lucy Lane suggests calling the Flash "Speedy", referencing Thea Queen's alter ego.
  • Cat tells Livewire and Silver Banshee, both her former employees, that they should call "Norma Rae" and ask her how it's done. This is a reference to the film of the same name where Sally Field played a union organizer.
  • Kara tells James that she wanted to discuss "infinite Earths". This phrasing is a reference to the DC Comics storyline Crisis on Infinite Earths.


Promotional images



  1. ‘Supergirl’ & ‘The Flash’ Reveal Key Art & Crossover Plot For ‘World’s Finest’ - Deadline