Mister Rogers plays a record of laughs and talks about laughing. Mister Rogers goes to Joe Negri’s music shop to listen to Phyllis Susan play the harp. Joe Negri gives Mister Rogers a harp record. In the Neighborhood of Make-Believe, Lady Elaine is about to tell everyone what she discovered on Jupiter. Lady Elaine is interviewed by a news reporter. She says that she discovered a new planet, The Planet Purple. Lady Elaine shows a picture of the planet. Everything on the planet is purple, and everyone looks alike.

Mister Rogers puts on an old shirt to protect his clothes while he plays with sand. Chef Brockett brings over a new cookie he has made. In the Neighborhood of Make-Believe, Mister Rogers and Mrs. McFeely try out some of Corney’s chairs because Corney is having a sale. A purple something drops out of the sky and Mr. McFeely takes it to Lady Elaine. It is a disk that answers questions about the Planet Purple. This informs them that all boys on the Planet Purple are named Paul and all girls are named Pauline. The purple platter also tells them that all chairs on the planet purple are the same. Lady Elaine tells Chef Brockett that all the food is purple on Planet Purple. He takes cookies to everyone in the Neighborhood of Make-Believe, but Lady Elaine has decided to only eat purple things.

Mister Rogers makes name tags for Francois Clemmons’ music classes. Miranda Sewell stops by and puts on her name tag. She tells Mister Rogers about the music class. Mister Rogers visits Francois’ music class. In the Neighborhood of Make-Believe, Francois Clemmons teaches Queen Sara Saturday a song. Lady Elaine Fairchilde refuses to talk to X the Owl because people don’t talk to owls on Planet Purple. She’s calling herself Pauline and calling all men Paul.

Mister Rogers and Bob Trow paint with a spinner. In the Neighborhood of Make-Believe, Lady Elaine is upset because she isn’t purple. She calls everyone Paul or Pauline. She argues with King Friday. The Purple Platter tells her that on Planet Purple the king is always right. Lady Aberlin and Robert Troll help convince her that there is an important place for her in the Neighborhood of Make-Believe. She decides to be herself. Back with Mister Rogers, he goes to Elsie Neal’s Craftshop where she and Bob Trow teach him to tie-dye.