|Season 9, Episode 12|
|Sine Qua Non||The Odessa Steps|
- Melissa Benoist as Kara Danvers/Supergirl & Red Daughter
- Chyler Leigh as Alex Danvers
- Katie McGrath as Lena Luthor
- Odette Annable as Reign & Samantha Arias
- Olivia Wilde as Susannah Russo
- Tyler Hoechlin as Clark Kent/Superman
- Claire Holt as Karen Starr/Power Girl
- Adelaide Kane as Ava Blackwood (credit only)
- Minka Kelly as Dawn Granger/Dove
- Jenna Dewan as Lucy Lane
- Michael Rosenbaum as Lex Luthor (Earth-30)
- Emmy Rossum as Zaora Dru-Zod
- with Laura Benanti as Astra In-Ze
- Mehcad Brooks as James Olsen/Guardian
- and David Harewood as J'onn J'onzz/Martian Manhunter
- Emmanuelle Chriqui as Sarah Essen
- Rachel Nichols as Slam Bradley
- Crystal Reed as Sofia Falcone
- Taylor Cole as Lady Liberty
- Meagan Rath as Onyx
- Jessica Rothe as Alexandra Luthor
- Andrea Brooks as Eve Teschmacher
- with Sam Witwer as Ben Lockwood
- and Matthew Fox as Matthew Etchison
- Antagonists: Sofia Falcone, Lady Liberty, Matthew Etchison
- Ava does not appear in this episode.
- This episode takes place on April 20, 2024.
- This trilogy of episodes is James-centric.
Community content is available under CC-BY-SA unless otherwise noted.