Watch Supergirl Online: Season 4 Episode 21

at .

Did Kara manage to take out the Red Daughter?

On Supergirl Season 4 Episode 21, the two sworn enemies came face-to-face and insanity ensued. 

With a tense battle, everyone tried to duck for cover when it emerged that they could both die in the fight. 

Meanwhile, Alex realized she was missing part of her memory, and tried to find out what was happening to her. 

Testing  - Supergirl Season 4 Episode 20

Elsewhwere, Brainy, Nia, and Jon set out find a way to take down Lex after he abducted a group of aliens. 

How did it all play out?

Use the video above to watch Supergirl online right here via TV Fanatic. 

Catch up on all your favorite shows and reviews and join in the conversations with other fanatics who love TV as much as you.

Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.

Show Comments
Tags: ,

Supergirl Season 4 Episode 21 Quotes

Jeez, this is America. You can't just kidnap a reporter.


Lena: Lex is planning on invading America.
Brainy: What?
Alex: You should have led with that.
Lena: Well, then you're gunna love this. Lex has a clone of Supergirl.
Alex: What?
Brainy: You should've led with that.