History is cyclic. War follows peace and onward into eternity. Avatar: The Last Airbender - The Promise Volume 3 shows that as the Harmony Restoration Movement collapses and the four nations are plunged back into the throws of war.
We were lucky enough to get a peek into the high-octane conclusion of The Promise graphic novels from Dark Horse Comics. Set between the original Avatar show and the steampunk inspired setting of Korra read about how the world changed under the watchful eyes of Aang, Katara, Toph, Sokka, Zuko and more.