Elseworlds, Part 2

The episode will be the second of the three-part crossover with the ninth episode of the fifth season of, and the ninth episode of the fourth season of.

Synopsis
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.

Trivia

 * The episode was previously titled "Hour Two".