Eun Seom's Ago Union and Tagon's Arthdal have the final battle in the Arth Forest.

Tan Ya who wants to change Arthdal's owner and Tae Al Ha who wants to protect Arthdal fight.

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?