Contains spoilers for this episode and earlier episodes.
Stan tries to make a visitor buy something by telling frightening stories about objects in the Mystery Shack. In his first tale, a stolen watch brings a curse from a witch who removes his hands. He returns with the twins and discovers that the witch's anger hides loneliness. Mabel helps improve her cave and appearance, persuading her to return the hands without the romance she wanted from Stan. His next sales pitch concerns Waddles. A mixture intended to increase Dipper's intelligence reaches the pig instead, giving him speech and the ability to invent machines. Dipper eagerly joins his scientific work, leaving Mabel without her familiar companion.
Waddles eventually chooses to give up his new intelligence so that he can enjoy being Mabel's pet again. Stan's third story begins when an old monster film frightens Mabel. Hoping to show her that its creatures are harmless models, the family visits the filmmaker Harry Claymore. He reveals that he animated them with magic and has since become their prisoner. The models attack, forcing Mabel to face her fear and rescue the others from being covered in clay. With the stories finished, Stan still cannot persuade the visitor to make a purchase. Stan offers a free sample of a potion, turning his hospitality into a trap. The unfortunate customer becomes his latest exhibit, displayed as a cheapskate who refused to buy any merchandise.