Supergirl makes a new ally. Lena and Lex battle for control of Luthor Corp.

When a mysterious ice powered enemy frames Frost for a brutal crime, she must find a way to clear her name. Meanwhile, Barry and Iris have a surprise houseguest, and Joe continues to deal with Kristen Kramer.

Jimmy invites people all over the world to show off their talents in a new Show Me Something Good, plays the Face It Challenge with Joseph Gordon-Levitt, catches up with Phoebe Robinson and welcomes musical guest Celeste.

Kevin visits Randall in Philadelphia.