Mister Rogers tries on different masks. Joe Negri is taking a census to learn if anyone has seen the red monster that frightened Sara Saturday. Betty Aberlin stops by dressed as a red monster and King Friday has set up a radar to alert them in the monster is nearby. Handyman Negri reports that, with the exception of Sara Saturday, no one in the real neighborhood or in the Neighborhood of Make-Believe has ever seen any monsters. Mister Rogers receives an invitation to watch the Neighborhood Ballet Company.

Mister Rogers brings oranges. He makes some orange juice, and saves some oranges to share with the ballet company. Mister Rogers watches as the company rehearses and prepares for their production, “The Sad Monster Ballet” in which a monster is sad because he has scared everyone away. He becomes happy when he learns to be friendly.

Mister Rogers fills bottles to different heights with water and blows into them. He plays “Tree Tree Tree” and “Joy to the World” on the bottles. Mr. McDonald plays music from Die Miestersinger by Wagner on the tuba. In the Neighborhood of Make-Believe, Digger Digorum, the archaeologist, has been summoned by the king to explore the tunnels in search of the mysterious red monster.

Mister Rogers makes a tunnel from a blanket and four chairs. Chef Brockett makes a tunnel from bread, peanut butter, and jelly. In the Neighborhood of Make-Believe, Digger Digorum, Daniel, and X see a flashing red light in the tunnel. They think it might be the red monster. When they find it is just a red flashlight, they agree that there are no monsters. Digger tells the king the great news, and he declares a holiday.