|First Air Date||:||2018-12-10|
|Genres||:||Crime, Drama, Mystery, Action & Adventure,|
With Oliver and Barry still stuck in the otherâ€™s bodies, the two get a lead on John Deegan and head to Gotham City with Supergirl to figure out why their reality has changed. While there, they meet the mysterious Kate Kane who provides them with information that leads the group to Arkham Asylum. The crossover starts on The Flash S05E09 Elseworlds (I) and concludes on Supergirl S04E09 Elseworlds (III).
|Casts||:||Rick Gonzalez, Katie Cassidy, Stephen Amell, Echo Kellum, Emily Bett Rickards, David Ramsey, Colton Haynes, Juliana Harkavy, Sea Shimooka,|