The two Flashes get help first from a retired Bruce Wayne, played once again by Michael Keaton. Together, the trio learns about a Kryptonian ship that crashed in Siberia. They track down the ship, thinking it belongs to Superman, but instead find Supergirl, who has been kept hidden in a research facility and tested upon since her arrival.
The idea of Supergirl being used as a test subject comes from 2011’s Project Superman #1, which told the story of Kal-El in the darker world that the comic book Barry Allen created when he went back in time in Flashpoint. At the end of the Flashpoint storyline, Barry puts things right when he goes back to the present. But he gets some things wrong, leading to the DC Universe reboot known as the New 52. With the reboot, the Project Superman story was more or less transformed to Supergirl, making Kara a darker and more angry character, who did not trust humanity.
The Supergirl of The Flash contained aspects of those stories. At first, Kara resented humanity for the way she treated her, and saw no reason to save them. But upon Barry’s urging, Kara found her more heroic side and joined the fight against Zod. Originally, the film would have ended with scenes setting up future movies with Calle’s Supergirl and Keaton’s aged Batman, with the former getting her own solo film written by Nogueira.
To this day, Nogueira says very little about that movie, telling Entertainment Weekly, “I don’t think I can even say what it was about, but it could not have been more different.” Presumably, however, we can guess that it would have followed the trajectory of the New 52 Superman comics. Those stories tracked Kara’s slow and circuitous route toward heroism, as she rejects the way of her cousin and finds her own path. The comic book version of this Supergirl sometimes did things her cousin would never consider, such as joining the rage-filled Red Lantern Corps. But she did the right thing more often than not.
Certainly, we can see some echoes of that Supergirl in the version played by Milly Alcock. While she’s never as antagonistic toward humanity as the New 52 character, this Supergirl has to find out how to be good in her own way, and ultimately finds a code that’s very different from the one held by Superman.
Would that Supergirl movie be better than the one now playing in theaters? There’s no way of knowing, but we can say with confidence that whether she’s a party girl trying to find her home or an alien making peace with a planet that mistreated her, she’ll always be Supergirl.
