Supergirl - Season 4 - Eps 21: Red Dawn
Kara comes face to face with Red Daughter and the two engage in an epic battle. Determined to find a way to extract the Harun-El, Lena turns to an unlikely source for help - Lillian Luthor. Meanwhile, Alex realizes she's missing parts of her memory, and Brainy, Nia and J'onn set out to track down aliens who have been abducted by Lex.
About Supergirl

Title: Supergirl
First Air Date: 2015-10-26
Last Air Date: 2021-11-09
Status: Ended
Rating: 7.306/10 (from 4223 votes)
Language: EN
Seasons: 6
Total Episodes: 126
Network: CBS The CW
Genres: Drama, Sci-Fi & Fantasy, Action & Adventure
Production Companies: DC Entertainment, Berlanti Productions, Warner Bros. Television
Synopsis
Twenty-four-year-old Kara Zor-El, who was taken in by the Danvers family when she was 13 after being sent away from Krypton, must learn to embrace her powers after previously hiding them. The Danvers teach her to be careful with her powers, until she has to reveal them during an unexpected disaster, setting her on her journey of heroism.
Cast

Melissa Benoist
Kara Danvers / Supergirl / Kara Zor-El

Chyler Leigh
Alex Danvers / Sentinel

David Harewood
J'onn J'onzz / Martian Manhunter

Katie McGrath
Lena Luthor

Jesse Rath
Querl 'Brainy' Dox / Brainiac-5

Nicole Maines
Nia Nal / Dreamer

Azie Tesfai
Kelly Olsen / Guardian

Julie Gonzalo
Andrea Rojas / Acrata

Staz Nair
William Dey

Peta Sergeant
Nyxlygsptlnz / 'Nyxly'