"Elseworlds" is the fifth Arrowverse crossover event that features episodes of The Flash, Arrow, and Supergirl on The CW. The crossover event began on December 9, 2018, with The Flash, continued on Arrow on December 10, and concluded on Supergirl on December 11. "Elseworlds" introduces the characters Batwoman and Lois Lane, and the fictional Gotham City, to the universe. In the crossover, Green Arrow, Flash, and Supergirl, the former two having had their powers and lives switched, are drawn to Gotham City to confront Dr. John Deegan over his work at Arkham Asylum.
The crossover was confirmed in May 2018 at The CW's upfront presentation, where the inclusion of Batwoman and Gotham City were revealed. Throughout August and September that year, casting for the crossover—including Ruby Rose as Batwoman, Elizabeth Tulloch as Lois Lane, and the announcement that Tyler Hoechlin would return as Superman—was revealed. The title of the crossover was announced at the end of September and filming began in October 2018. In "Elseworlds", Arrowverse actors portray other roles and John Wesley Shipp reprises his role as Barry Allen / Flash from the 1990 series The Flash. The conclusion of "Elseworlds" set up "Crisis on Infinite Earths" as the next crossover, which aired between December 2019 and January 2020.
Plot Part 1
On a ravaged Earth-90, The Flash escapes the planet’s destruction while a mysterious figure uses a powerful book. On Earth-1, the same figure gives the book to Arkham Asylum psychiatrist John Deegan, who uses it to rewrite reality according to his will. The following day, Oliver Queen and Barry Allen wake up in each other's lives. Team Flash does not believe them and locks them up in the S.T.A.R. Labs pipeline. Oliver and Barry use each other's abilities to escape and travel to Earth-38 to get help from Kara Danvers and acquaint themselves with her cousin Clark Kent and Lois Lane, in Smallville, Kansas. Meanwhile, an android called A.M.A.Z.O. awakens and threatens Central City. Cisco Ramon retrieves Oliver and Barry from Earth-38, with Kara and Clark helping. After defeating A.M.A.Z.O., Clark returns to protect Earth-38. Cisco vibes Deegan and the mysterious figure, who sees Cisco using his powers and warns the group that something is coming and they will not be able to stop it. Oliver realizes the figure and Deegan were located in Gotham City.
Part 2
In Gotham, Barry, Oliver and Kara are arrested by the GCPD. They are bailed out by Wayne Enterprises' CEO Kate Kane, who tells them Deegan is at Arkham Asylum. The trio, with the assistance of Caitlin and Diggle, break into Arkham to confront Deegan. They retrieve the "Book of Destiny" but Deegan escapes by causing a mass breakout. During a confrontation with inmate Nora Fries, Barry and Oliver are exposed to fear gas and believe each other to be Malcolm Merlyn and Eobard Thawne, respectively. After stopping the breakout, Kate, as the vigilante Batwoman, rouses them from their hallucinatory state and tells them to leave Gotham. They head to A.R.G.U.S. to restore reality, where Earth-90's Flash warns them about Mar Novu, who is testing worlds for an impending crisis. They confront Novu, who breaches away Earth-90's Flash, reclaims the book and returns it to Deegan, who writes a new reality in which Barry and Oliver are powerless criminals known as the Trigger Twins and are confronted by a black-suited Superman.
Part 3
Oliver realizes the Superman impostor is actually Deegan before forcing him to save innocents while they escape to find Cisco. Deegan and his forces, including the Earth-1 doppelgänger of Kara's adoptive sister Alex Danvers, are holding Kara at S.T.A.R. Labs. Barry and Oliver locate Cisco and persuade him to take them to Earth-38. They find Clark, who agrees to return with them to Earth-1 while Kara persuades Alex to release her. Arriving on Earth-1, Clark and Oliver fight Deegan and his forces while Alex, Barry, and Kara locate the Book of Destiny in the Time Vault and take it to Clark, who restores Barry, Oliver, and Kara to their real selves. Deegan retrieves the book and attempts to rewrite reality again. To impede his progress, Barry and Kara slow down time by speeding around the Earth in opposite directions. Oliver confronts Novu, asking him to spare Barry and Kara, but Novu demands something from Oliver in exchange. Clark, joined by Lois, Brainiac 5, and J'onn J'onzz, fights Deegan and a revived A.M.A.Z.O. Barry and Kara are nearly torn apart by their speed but Oliver shoots the book with an arrow enhanced by Novu. Deegan reverts to himself, though heavily disfigured, and reality is restored. After returning to Earth-38, Clark and Lois tell Kara they are expecting a child and will return to Argo City, leaving Earth's protection to her. On Earth-1, Oliver is contacted by Kate, who says Deegan, now incarcerated at Arkham, has made a new friend who tells Deegan: "Worlds will live, worlds will die, and the universe will never be the same".
Cast and characters
Main and recurring
+ Actor Character Episode The Flash Arrow Supergirl Grant Gustin Barry Allen / Flash rowspan="2" rowspan="2" colspan="2" Oliver Queen / Green Arrow Candice Patton Iris West-Allen colspan="2" Danielle Panabaker Caitlin Snow / Killer Frost colspan="2" Carlos Valdes Cisco Ramon / Vibe colspan="2" Hartley Sawyer Ralph Dibny / Elongated Man colspan=2 Tom Cavanagh "Sherloque" Wells colspan=2 Eobard Thawne / Reverse-Flash Stephen Amell Oliver Queen / Green Arrow rowspan="2" rowspan="2" rowspan="2" Barry Allen / Flash David Ramsey John Diggle Tyler Hoechlin Clark Kent / Superman John Deegan / Superman colspan="2" Melissa Benoist Kara Danvers / Supergirl colspan="2" Jeremy Davies John Deegan colspan="3" LaMonica Garrett Mar Novu / Monitor colspan="3" Elizabeth Tulloch Lois Lane Emily Bett Rickards Felicity Smoak Echo Kellum Curtis Holt Kirk Acevedo Ricardo Diaz Ruby Rose Kate Kane / Batwoman colspan="2" Bob Frazer Roger Hayden / Psycho-Pirate colspan="2" Cassandra Jean Amell Nora Fries colspan="2" John Wesley Shipp Barry Allen / Flash (Earth-90) Mehcad Brooks James Olsen (Earth-1) colspan="2" Chyler Leigh Alex Danvers (Earth-1) colspan="2" Jesse Rath Querl "Brainy" Dox / Brainiac 5 colspan="2" David Harewood J'onn J'onzz / Martian Manhunter colspan="2" Despite being credited, Jesse L. Martin does not appear in The Flash episode; Rick Gonzalez, Juliana Harkavy, Colton Haynes, Sea Shimooka and Katie Cassidy do not appear in the Arrow episode; and Katie McGrath, Sam Witwer, Nicole Maines, and April Parker Jones do not appear in the Supergirl episode.
Guests Liam Hall as Kane Wolfman (Arrow) John Barrowman as Malcolm Merlyn (Arrow) Adam Tsekhman as Gary Green (Supergirl)
Production
Development
Coming off "Crisis on Earth-X", the previous year's crossover, executive producer Marc Guggenheim noted that the process to pull off that crossover had made each series' crews "pretty burned out", with them "feeling the effects of it literally a year after". This led the producers to want to take a year off from the yearly crossovers, but were convinced by The CW to create another when they allowed the crossover to not be with all four series as "Crisis on Earth-X" had been. In May 2018, The CW president Mark Pedowitz and Arrow lead Stephen Amell announced at The CW's upfront presentation that Batwoman, fighting alongside the other Arrowverse heroes, would be introduced in the upcoming crossover. The fictional Gotham City would also appear. Despite the inclusion of the character and city, the crossover would not include the television series Gotham that airs on Fox. That July, The CW was planning a potential standalone Batwoman series after her appearance in the crossover; Caroline Dries, who was creating and writing the potential Batwoman series, was expected to consult on the crossover. It was confirmed that Legends of Tomorrow would not feature in the crossover. Legends of Tomorrow co-showrunner Phil Klemmer said because the crossover was being used to launch the Batwoman-led series, "it just became over capacity", and that because Legends of Tomorrow would have a 16-episode season, the crossover would have been "a tonal speed-bump, or a departure, and we just don't have time to step away from our story this year". Despite not being part of the official crossover, Legends of Tomorrow co-showrunner Keto Shimizu revealed "Legends of To-Meow-Meow", the show's episode airing the week of the crossover, would be "crossing over with ourselves" through the use of alternate time periods, and Adam Tsekhman guest stars as Gary Green in the Supergirl episode.
At the end of September 2018, the title of the crossover was announced as "Elseworlds", sharing the name of the Elseworlds imprint of comics from DC Comics that takes place outside the DC Universe canon. The producers initially considered titling it "Identity Crisis" but abandoned the idea because, according to Guggenheim, this title would be "false advertising, because we're obviously not doing the Brad Meltzer, Rags Morales Identity Crisis story".
Writing The story for "Elseworlds" was created by Greg Berlanti, the executive producers and writers from each series, Geoff Johns, and Dries. Arrow showrunner Beth Schwartz referred to these people as "the Super Writers' Room", and noted that Marc Guggenheim, who was a consultant on Arrows seventh season, had "taken the lead on the crossover", acting as the showrunner for it. The Flash episode was written by Eric Wallace and Sam Chalsen, the Arrow episode features a story by Caroline Dries and a teleplay by Marc Guggenheim, and the Supergirl episode features a story by Marc Guggenheim and a teleplay by Derek Simon and Robert Rovner. The episodes' scripts were completed by mid-September 2018. Guggenheim said "Elseworlds" would have a long-lasting impact for the Arrowverse and "lays the groundwork for next year's crossover". At the conclusion of "Elseworlds", it was revealed that the next crossover would be "Crisis on Infinite Earths" in late 2019, adapting the storyline from the comic of the same name.
The preceding episodes of each series feature "puzzling events" that lead to the events of the crossover. The same end-credits scene teasing the events of crossover was shown at the end of the episodes "Bunker Hill", "Unmasked", and "What's Past Is Prologue". The scene also confirmed Earth-90 as the earth for the Flash from the 1990 television series. Guggenheim said the tease was "cool because we've never ... setup the crossover in the previous episodes before". The tease was meant to be one of two options for the "Elseworlds" cold opening. The writers could not choose which opening they would use; Guggenheim said someone decided to "take one cold open, move that and make that the post-credit tag, like the way The Flash typically does, at the end of all three shows, and then have the other cold open at the beginning of hour one". Supergirl co-showrunner Robert Rovner said the tease was only supposed to air with Flashs "What's Past Is Prologue"; it was added to the other two episodes to make things easier for viewers because they "are coming to [the crossover] from our separate shows and we wanted something that [connects them together]".