Mister Rogers uses colored water and test tubes of different sizes to discuss relative size and volume. He talks about drains and how people are too big to go through them. Mister Rogers shows how water goes through a pipe by drinking milk through a transparent straw. He spills some of the colored water on the floor and on his shoes. He doesn’t like the way it feels. In the Neighborhood of Make-Believe, King Friday wants a waterfall, so he orders Handyman Negri to pour water from one pitcher to another. Donkey Hodie suggests installing plumbing for a real waterfall. Corney orders pipes for the project.