Plot summary
Near Zaofu, Opal, Lin, and Bolin are joined by Toph and track the Beifong prisoners to a facility where Baatar Jr. and Zhu Li are testing a vine energy supercannon. A rescue plan takes form, but tensions run high between the previously estranged Toph and Lin. Zhu Li proves to have been feigning her loyalty to Kuvira and attempts to sabotage the weapon, but her effort is discovered by Kuvira. The rescue team frees the captive Beifongs, who engage Kuvira and her forces together, before being forced to flee by Kuvira's superior numbers. Lin and Toph find a measure of reconciliation. Zhu Li reveals that Kuvira is planning an imminent attack on Republic City; she is determined to retake all of the lands which the Earth Kingdom had once ceded to the United Republic. Meanwhile, Korra tries and fails to convince the spirits to help defend Republic City.
Credits
Adapted from Wikipedia contributors, The Legend of Korra season 4. HTML formatting and reference markers removed.