Ep 21. Red Dawn

In Supergirl season 4 episode 21, titled "Red Dawn," Kara is facing one of her toughest challenges yet as she tries to stop Lex Luthor from using the alien technology he has gathered to create a new weapon. With the help of her sister Alex, and her friends Brainy and Nia, Kara sets out to stop Lex and save the world from his nefarious plans.

The episode begins with Lex activating his latest creation, a weapon capable of causing devastating earthquakes that could destroy entire cities. Kara and her team rush to stop him but they are too late, the device has gone off and the damage is already done. Kara is devastated, knowing that it is her responsibility to protect the people of Earth from these kinds of threats.

Meanwhile, Alex is dealing with her own problems as she tries to navigate her new position as the head of the DEO. She is forced to make difficult decisions as she tries to keep her agents and the people of National City safe from the fallout of Lex's actions.

As Kara and her team try to track down Lex, they discover that he has a new ally, a woman named Eve Teschmacher. Though they don't know her true allegiance, they suspect that she is working with Lex to further his plans.

As they get closer to stopping Lex, Kara and her team begin to realize the full extent of his plan. Not only is he using alien technology to create weapons, but he is also using it to create a new, ultra-powerful version of himself. This version of Lex, known as "Luthor 2.0," is stronger and smarter than ever before, and Kara knows that she will have to be at her best to stop him.

The tension builds as Kara and her team race to stop Lex and his plans before it's too late. Will they be successful in their mission to save the world, or will Lex succeed in his nefarious plans? It all comes down to the final showdown between Supergirl and Luthor 2.0.

In "Red Dawn," Supergirl faces her toughest challenge yet as she battles to stop Lex Luthor and save the world from his evil plans. With the help of her friends and allies, Kara fights to protect the people of Earth and keep them safe from harm. Don't miss this thrilling episode filled with action, drama, and heart-stopping moments.