Eight years have passed since Tagon took the throne as the second coming of Aramun. Eunseom succeeded in uniting the Ago clans as the second coming of Inaishingi, and he led them to the great war against Arthdal.
The first battle between Arthdal and the United Ago forces occurred in Hanchoa. Tagon realizes the elevated status of Tanya as the second coming of Asa Sin and begins to feel threatened by her absolute power.
The final battle between the Ago Union and Arthdal has come. Ta Gon prepares for a personal war. Tanya, Tae Al Ha, Sa Ya, and Eun Seom make one final move to protect what's most precious to them. Who will take over Arthdal?