Ep 15. O Brother, Where Art Thou?

As a powerful force threatens to destroy National City, Supergirl must team up with her arch-enemy, Lex Luthor, to stop it. In this episode, titled "O Brother, Where Art Thou?," we see Lex's backstory and how he became the man he is today.

The episode begins with a flashback to Lex's childhood. We see a young Lex being bullied by his father Lionel Luthor, who is disappointed in his son's lack of athletic ability and instead encourages him to focus on his intellect. We also see Lex's relationship with his sister Lena, who is the only person he trusts and confides in.

Fast forward to the present, and we see Lex (played brilliantly by Jon Cryer) in prison, serving multiple life sentences for various crimes he committed in the past. However, he is offered a chance at freedom by the government if he helps Supergirl stop a powerful alien threat known as "Leviathan."

Reluctantly, Supergirl agrees to work with Lex, but she doesn't trust him and keeps an eye on him at all times. Meanwhile, Lena discovers that Lex is alive and working with Supergirl, and she is understandably skeptical and angry.

Throughout the episode, we see flashbacks to Lex's past, including his first encounter with Leviathan and his desperate attempt to save his own life. We also see how his relationship with Lena has changed over the years, as his obsession with power and control slowly erodes their bond.

As Supergirl and Lex work together to stop Leviathan, they clash over their differing ideologies and methods. Supergirl believes in protecting all life, while Lex is willing to sacrifice innocent lives in order to achieve his goals. This dynamic leads to some intense and emotional scenes, especially when Lena enters the picture and confronts Lex about his past actions.

Ultimately, Supergirl and Lex are able to stop Leviathan, but at a great cost. Lives are lost, and the city is left in ruins. The episode ends with Lex being granted his freedom, but it's clear that his true motives are still shrouded in mystery.

Overall, "O Brother, Where Art Thou?" is a standout episode of Supergirl that delves deeper into the character of Lex Luthor and his complicated relationship with his family. Jon Cryer's performance is especially noteworthy, as he brings both charisma and depth to a character that could easily become cartoonish in the wrong hands.