Prince Arok, the son of Tagon and Taealha, is abducted, and the Arthdal Palace is in an uproar.

The last prophecy by Aramun is announced. Eunseom, Tanya, and Saya try to figure out what it means!

Saya tries to take over the Ago Union. With Tagon's orders, Arthdal faces a new crisis.