|Season 8, Episode 9|
|An Exercise in Futility||The Box|
PART 1 OF 2: SLEEPING SOMEWHERE COLD- Sam's recurring dreams of Reign take her on a journey to the very heart of the cosmos. Kara Danvers and Lena Luthor work with Lor-Zod to break Zaora's hold on the populace of New Kandor. Lex signs into law a bill protecting aliens.
- Melissa Benoist as Kara Danvers/Supergirl & Red Daughter
- Chyler Leigh as Alex Danvers
- Katie McGrath as Lena Luthor
- Odette Annable as Samantha Arias/Reign
- Olivia Wilde as Susannah Russo
- Jenna Dewan as Lucy Lane
- Adelaide Kane as Ava Blackwood
- with Minka Kelly as Dawn Granger
- and Emmy Rossum as Zaora Dru-Zod
Special Guest Stars
- Jon Cryer as Lex Luthor
- Michael Rosenbaum as President Lex Luthor (Earth-30)
- James Frain as Nekron
- Mehcad Brooks as James Olsen
- Claire Holt as Karen Starr (holocall)
- Luke Evans as Bruce Wayne
- with Jeffrey Dean Morgan as Ran-Zod
- and David Harewood as J'onn J'onzz (dreams)
- Brenda Strong as Lillian Luthor
- Troian Bellisario as Mary Seward
- Daniel Sharman as General Lor-Zod
- Laura Vandervoort as Gabriel
- Teressa Liane as Mary Louise Fairchild
- Scarlett Byrne as Nora Fairchild
- Esme Bianco as Elsala Sym-Ro
- Gemma Chan as Sirona Mol-Je
- Eka Darville as Kell-Zur
- Andrea Brooks as Eve Teschmacher
- Lili Reinhart as Sub-Commander Aethryr
- Tasya Teles as Destri Sol-Gud
- Wallis Day as Nyssa-Vex
- with Dianna Agron as Major Raya Dru-Zod
- and Sam Witwer as Ben Lockwood
- Antagonists: Nekron, Mary Seward, Ava Blackwood, Zaora Dru-Zod, Gabriel
- 2nd episode this season to feature all main characters.
- This episode is Sam-centric.
- James was last seen in I Will Always Protect You, No Matter What.
- This episode takes place on February 20, 2024.