When Robbie's girlfriend's father calls from out of town and asks him to deliver a birthday cake to her, he thinks there might be a fortune in performing this birthday service and immediately goes into the cake business.

Chip becomes violently ill after eating Polly's cooking, and she learns from the family that Chip is allergic to some of the foods she's been preparing. Distressed, she feels it would be better for her husband if she left him.

Against his classmate's better judgement, Ernie uses the unwitting Douglas household as guinea pigs for an experiment assigned by his psychology teacher. He cuts inches off Uncle Charley's cane to make him think he is growing taller. Ernie soon finds his father Steve is a little less gullible.