Episode Title:The Terror Within.Episode Description:In Zaofu, Korra and Bolin continue to learn metalbending, and Opal leaves for the Northern Air Temple. At night, Zaheer and his team infiltrate Zaofu and capture Korra, but Team Avatar, backed up by Lin, Suyin and a contingent of metalbenders, are able to rescue the avatar, and the assailants retreat. In the subsequent investigation, Korra and her friends discover that Suyin's adviser Aiwei has been aiding Zaheer, but he escapes through a secret tunnel. Later, with the help of Suyin, Team Avatar sneaks out of Zaofu to pursue the attackers.