This week's theme of Go-Stop-Go is about impulse control. Knowing when to stop and when to go deals with some of the most essential things in childhood -- learning, getting along with others, toilet training, and safety rules. There's a fire drill at a school and a visit to a Fire Department where Mister Rogers meets caring fire fighters. Mister Rogers shows a video of different kinds of fountains and shows how he turns the water on and off in his bathroom. Author/illustrator Marc Brown shows how he draws the "Arthur" character and introduces Mister Rogers to the teenager who does the voice of "Arthur" on PBS. In the Neighborhood of Make-Believe story, Lady Elaine has trouble controlling her urge to squirt her Museum-Go-Round hose. With the help of her friends, she finds that there are times when it's okay to squirt the water and times when it's not okay -- times to go and times to stop.