In three separate mysterious tales, Stan is cursed by a Witch, Waddles accidentally eats a bowl of brain-enhancing jelly and builds a machine that allows him to speak, and Mabel faces her fear of claymation.

After agents Powers and Trigger take Stan into custody, Dipper and Mabel begin to wonder how much they actually know about their Grunkle Stan.

Dipper finds an unlikely friend to join him with his newest obsession, a board game called “Dungeons, Dungeons & More Dungeons.”

Mabel makes plans for her and Dipper's 13th birthday party; Dipper ventures below the town and discovers its most shocking secret.