'Supergirl' Season 4 Spoilers: Who Will Turn Red Daughter Against Lex?

Supergirl Season 4 finally finds its footing by revealing that Lex Luthor had a finger in nearly every pie of its convoluted plot, but can he maintain his hold on those he needs to bring his plans to fruition?

In Episode 16, we see Lex was manipulating Red Daughter to work for him, but we also see two areas of weakness that can be used to turn her against him.

Spoilers for Supergirl Season 4 Episode 16 below.

“The House of L” is Red Daughter’s origin story. When she arrived in Kasnia nine months ago, she only remembered Alex’s name. Over the subsequent months, Lex takes advantage of that and becomes her “Alex.” He trains and manipulates her into hating America and Supergirl.

After a trip to Kara’s apartment, during which she pretends to be her doppelganger with Alex and reads Kara’s journal, Red Daughter begins questioning everything. To keep her on his side, Lex decides to kill a Kasnian boy, Mikhail, who she saved and befriended, and then blames the Americans. Red Daughter correctly surmises that everything Lex has been doing is about his sister, and he storms off in a huff.

Lex Luthor and Red Daughter fight in 'Supergirl' Season 4 Episode 16.

The CW

However, when she becomes ill, Lex saves her. By giving himself cancer, he motivated Lena into finishing the Harun-El serum, which he then passes along to Red Daughter via a blood transfusion. When Red Daughter wakes up, she’s once again ready to follow Lex and destroy Supergirl.

But what could change that? Supergirl Season 4 Episode 16 gives us two possibilities.


No matter what changes, whether Alex knows the truth about Kara or not, their sisterly bond is arguably the most important part of the entire series. The fact that Alex’s name was the only thing that Red Daughter remembered is proof of that.

Their relationship shaped them into the people they are today, and so it makes sense that Red Daughter’s “Alex” would influence her as he had.

However, after the trip to Kara’s apartment, Red Daughter now knows about Alex. She’s even spoken with her. No matter what Lex has done to sway her view, that has to come into play before the end of the season.

If Kara and Alex can get Red Daughter to see and accept that Lex has been lying to her from the beginning, about that one fundamental detail that kick-started their partnership, it’s possible they can use that to turn her against him.


Lex thinks he killed the boy. However, Otis Graves saves Mikhail without his boss’ knowledge and warns him to stay clear of all bald men.

Red Daughter thinks Mikhail is dead, but if she learns he isn’t, that may be enough for the whole truth about the missile to come out. If she learns what Lex did, that could turn her against him.

How Will Season 4 End for Red Daughter?

What we do know is she likely won’t be sticking around next season. It’s hard to imagine two Karas running around in National City or even the world. Kara could send her to Argo City, the last surviving piece of Krypton, whether she changes sides or not.

If Red Daughter does turn against Lex, she may very well try to kill him for what he did. However, that could keep her and Supergirl at odds, since Kara likely wouldn’t agree with her plan for murder. That could also influence what happens to her when it’s all over.

Red Daughter could also die, whether in battle or as a side effect of the Harun-El transfusion. (We still don’t know exactly what will happen to those who have received the serum.)

Supergirl Season 4 airs Sundays at 8 p.m. on The CW.

Related video: Lex Unleashes Red Daughter in Supergirl Season 4 Episode 16 Trailer

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