Kara is the only person who believes Lena is innocent and must save her from Lillian.
Season 2, Episode 12
Previous: “The Martian Chronicles”
Next: “Mr. & Mrs. Mxyzptlk”
John Corben is being questioned during Lillian Luthor's trial when he attacks the courtroom using his Metallo abilities.
Source: What's Filming — Twitter
Kara tries to stop Lillian and Metallo from fleeing but is forced to save a bunch of bystanders.
Lillian takes Lena to one of Lex's hidden lairs to retrieve some anti-alien weapons from an armory.