Season 1, Episode 18
|Airdate||March 28th, 2016|
|Writer||Andrew Kreisberg; Michael Grassi; Greg Berlanti|
|Producer||Joanie L. Woehler; Jennifer Lence; Carl Ogawa; Michael Grassi; Ted Sullivan; Michael Cedar; Roberto Aguirre-Sacasa; Yahlin Chang; Sarah Schechter; Ali Adler; Andrew Kreisberg; Greg Berlanti; Curtis Krick|
|Starring||Melissa Benoist; Mehcad Brooks; Chyler Leigh; Jeremy Jordan; David Harewood; Calista Flockhart|
'Worlds Finest" is the eighteenth episode of season one of the superhero action series Supergirl. It was directed by Nick Gomez with a script written by Andrew Kreisberg and Michael Grassi based on a story treatment by Greg Berlanti. It first aired on CBS on Monday, March 28th, 2016 at 8:00 pm. This is a special episode of the series as it is an inter-network crossover between CBS and the CW Network television series The Flash. Actor Grant Gustin, who plays Barry Allen on the series, is a special guest star in this episode.
Principal Cast Edit
|Melissa Benoist||Supergirl, Kara Danvers|
|Mehcad Brooks||James "Jimmy" Olsen|
|Chyler Leigh||Alex Danvers |
|Jeremy Jordan||Winn Schott|
|David Harewood||Hank Henshaw |
|Calista Flockhart||Cat Grant|
Guest Stars Edit
|Grant Gustin||The Flash, Barry Allen|
|Jenna Dewan Tatum||Lucy Lane|
|Italia Ricci||Silver Banshee, Siobhan Smythe|
|Brit Morgan||Livewire, Leslie Willis|
|Harriet Sansom Harris||Sinead|
|Jay Jackson||News anchor|
|Dawn Greenidge||Pedestrian woman|
|Sarah Robson||Amelia Hamilton|
|Dan Warner||Fire Chief|
Notes & Trivia Edit
- Supergirl was created by Greg Berlanti, Ali Adler, and Andrew Kreisberg based on the comic book superhero featured in titles published by DC Comics.
- This episode is rated TV-14.
- This episode is production code number 4X7618.
- This episode had a viewership of 7.166 million people, which is up by 1.171 from the previous episode. It scored 1.7% in the 18-49 demographic. 
- This is the fourth episode of Supergirl with Andrew Kreisberg as either a co-writer or a story developer.
- Central City exists in both Barry Allen's reality, and Supergirl's reality.
- This is the first appearance of Doctor Amelia Hamilton, who is an analog for Professor Emil Hamilton, a DC Comics scientist and a supporting character in both the Superman comic franchise, as well as the TV series Smallville.
- This is the second appearance of Leslie Willis, aka Livewire. She appeared last in episode 1x04, "Livewire".
- This is the first episode of the series with Siobhan Smythe assuming the guise of the Silver Banshee.
- The Fire Chief that appears in this episode is the same one that appeared in episode 1x16, "Falling".
- Barry Allen makes reference to Cisco Ramon in this episode. Cisco Ramon is a scientist for S.T.A.R. Labs and one of Barry's closest friends. He is a regular character featured on The Flash.
- Barry Allen makes reference to Caitlin Snow in this episode. Caitlin Snow is a scientist for S.T.A.R. Labs and one of Barry's closest friends. She is a regular character featured on The Flash.
- Barry Allen makes reference to Harrison Wells in this episode. Harrison Wells is a scientist from Barry's original reality, Earth-One, who was murdered by Eobard Thawne and had his identity supplanted by him. Another Harrison Wells, "Harry" Wells, is a scientist from Earth-Two, who immigrated to Earth-One and joined the staff at S.T.A.R. Labs.
- Barry Allen makes reference to Firestorm in this episode. Firestorm is a gestalt being, who is comprised of two individuals who fuse together. Originally, Firestorm was Ronnie Raymond and Professor Martin Stein. After Ronnie's apparent death, the Firestorm coupling consisted of Stein and Jefferson Jackson.
- Barry Allen makes reference to Green Arrow in this episode. Green Arrow's real name is Oliver Queen, and he is a masked superhero who operates out of Star City (formerly Starling City).
- Barry Allen makes reference to Black Canary in this episode. There have been two Black Canaries in Barry's reality. The first was Sara Lance, who was killed in action, but later resurrected. During the time that Sarah was dead, her sister, Laurel Lance, became the new Black Canary.
- Cat Grant insists on naming this new superhero The Blur. This is a wink to the CW Network television series Smallville, where the character of Clark Kent was often referred to as either the Blur, the Blue Blur, or the Red-Blue Blur.
- The Flash: You don't seem that bothered by the fact that you're on fire.
- James Olsen: So, so you're a superhero too?
- Barry Allen: Mmm hm!
- James Olsen: That - that's cool I guess.
- Cat Grant: need a clear picture of this Speedster, James that's on you. Kara, there are a lot of people that want to know what happened, speak to no one. You're mine. I will let you know when you should reveal this exclusive information.
- Cat Grant: The Flash? Sounds like someone whose only superpower is jumping out of an alley in a trench coat.