Eunseom and Do Ti run into a familiar face in Arthdal and make an alarming discovery. San Woong grows suspicious of his son. Tanya stands up for her tribe.

As Tagon's declaration ripples through Arthdal, Eunseom contemplates the significance of what he saw. Moo Baek seeks advice and is given a quest.

Taealha counsels Tagon about the impending meeting with Eunseom. Mi hol tries to persuade Asa Ron to expose the truth. Tanya sees a mystifying vision.