Contains spoilers for this episode and earlier episodes.
A label inside the smashed laptop directs Dipper toward McGucket, raising the possibility that the town's eccentric inventor wrote the journals. McGucket cannot remember enough of his past to answer, but a strange symbol points them toward a secret organization beneath the museum. Dipper, Mabel, Wendy and Soos follow him inside and watch robed townspeople erase Lazy Susan's memories of encountering gnomes. The Society of the Blind Eye removes evidence of the supernatural from people's minds and stores the recordings. Dipper searches for McGucket's lost memories, while Mabel considers using the same device to forget her disappointing summer romances. Wendy warns her that painful experiences are still part of her life.
The society captures the group and prepares to erase everything they know about Gravity Falls. McGucket frees his friends and shields Dipper from the memory gun, whose effects cannot do much more to his already damaged mind. They defeat the members and erase their knowledge of the organization. Outside, McGucket watches his recovered recordings. He was the journal author's assistant, helping to build a machine before a terrible experience made him quit. He invented the memory gun to forget, founded the society and gradually damaged himself through repeated use. Knowing what happened gives him a chance to recover. Mabel chooses to keep her own difficult memories, and the search for the author continues with a clearer account of McGucket's past.