Supergirl (2015)

S4E15 O Brother, Where Art Thou?

Due to his deteriorating health, Lex Luthor is secretly released from prison and approaches his sister, Lena, for assistance in finding a cure. Although Lena remains cautious about Lex's intentions, she finds herself in a life-and-death dilemma that forces her to confront her feelings for him. At the same time, Supergirl and J'onn engage in a battle with Manchester Black. Additionally, James' sister Kelly arrives in town, adding another layer of complexity to the unfolding events.