With Oliver and Barry still stuck in the other’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).
Quest roles:
John Barrowman(Malcolm Merlyn / Narrator (voice)), Kirk Acevedo(Ricardo Diaz), Sea Shimooka(Emiko Queen), Jeremy Davies(John Deegan), Bob Frazer(Roger Hayden / Psycho-Pirate), Cassandra Jean Amell(Nora Fries), Danielle Panabaker(Caitlin Snow / Killer Frost), Tom Cavanagh(Harrison 'Nash' Wells (uncredited)), John Wesley Shipp(Barry Allen / The Flash (Earth 90)), LaMonica Garrett(Mar Novu / The Monitor (uncredited)), Liam Hall(Joseph Wilson / Kane Wolfman), Ruby Rose(Kate Kane / Batwoman), Grant Gustin(Barry Allen / The Flash), Melissa Benoist(Kara Danvers / Supergirl), Carlos Valdes(Cisco Ramon), Tyler Hoechlin(Clark Kent / Superman), Violet Cameron(GCPD Officer #2), Mick Major(Orderly), London Morrison(Nurse)