Korra and her friends hide in an underground settlement until Iroh's fleet arrives, which is promptly disabled by Equalist mines and aircraft. After Korra saves Iroh from drowning, she and Mako go in search of Amon and discover the captive Tarrlok, who reveals that Amon is his brother Noatak and also a bloodbender, driven to revenge on benders by their father Yakone. Meanwhile, Korra's friends prepare an assault on the Equalists' mountain airbase to prevent the sinking of a relief fleet under Commander Bumi, Tenzin's brother.