Episode Title:
Not What He Seems.
Episode Description:
After government agents take Stan into custody, Dipper and Mabel begin to question how much they really know about their Grunkle and must work out whether or not they truly trust him anymore. Finally, the portal is activated and the author of the journals is revealed to be Stan's long-lost brother, who emerges from the portal as Dipper, Mabel, Soos and Grunkle Stan look on.
