Mister Rogers puts on a lab coat and begins experimenting with a metal hoop which he tosses in the air. He matches the circle shape with other shapes. Mr. McFeely arrives with a delivery of different sized balls which Mister Rogers counts and experiments with, using the hoop. Mister Rogers talks about cleaning up. In the Neighborhood of Make-Believe, Mr. McFeely delivers two invitations to Lady Elaine Fairchilde for a boomerang contest. Chef Brockett offers to accompany Lady Elaine, and she teaches him to throw the boomerang. Lady Elaine shows Mr. McFeely a Funny Fast Film about himself, and also shows Chef Brockett a Funny Fast Film about himself.
Mister Rogers arrives with a puzzle in the shape of a ball that Robert Trow has lent him. After Mister Rogers dismantles the ball and counts the parts, he reassembles it. Mister Rogers then visits Robert Trow and plays counting games with him using flash cards. At Bob Trow’s shop, Bob and Mr. Rogers play rhyming games with number flash cards. Mister Rogers names words that rhyme with the numbers. Mister Rogers returns home and plays more of the rhyming game. In the Neighborhood of Make-Believe, Bob Dog finds Lady Elaine’s boomerang and takes it to Cornflake S. Pecially. Lady Elaine becomes angry that Bob Dog will not return the boomerang when she rudely asks for it. Cornflake persuades Lady Elaine to ask Bob Dog politely. At the boomerang contest, Robert Troll, Chef Brockett, Barbara Boomerang, and Donkey Hodie practice throwing the boomerang. Lady Elaine’s boomerang fast throw wins her first place. Barbara Boomerang crowns herself the Contest Queen. Lady Elaine becomes angry that she is not queen, but is content with being first.
Mister Rogers arrives with a dozen eggs of different sizes and shapes. Mister Rogers and Dr. Parks from the museum label each egg with the name of its parent bird or animal. Mr. McFeely arrives with a picture book about animals and birds and their eggs. In the Neighborhood of Make-Believe, Digger Diggorum learns from the king and queen that the queen is expecting a new royal baby. Handyman Negri visits Lady Elaine and congratulates her on winning the boomerang fast-throw contest the day before. Elsie Jean Platypus announces exciting news about her newly laid egg. Lady Elaine is happy the egg will hatch in only 10 days, before the king’s baby is born. In Mister Rogers’ home, he shows his viewers the picture book that Mr. McFeely brought over earlier about animals and bird eggs.
Mister Rogers arrives with a film showing eggs hatching. Chef Brockett stops by and shows Mister Rogers how to make donuts. In the Neighborhood of Make-Believe, King Friday XIII learns of the Platypus’ egg and decides that Elsie Jean and Dr. Bill must leave the neighborhood and not return until the royal baby is born.
Mister Rogers shows pictures from a book about animals and their babies. After viewing the animal book again, Mister Rogers explains that babies look like their parents. In the Neighborhood of Make-Believe, X and Henrietta are upset about King Friday’s orders to have the Platypus family leave the neighborhood until after his child is born. The King wants his baby to be the first born in the neighborhood. Dr. Bill and Digger Digorum go to the castle to ask King Friday to change his mind. Queen Sara learns of Friday’s orders and explains to him that the king’s baby will be the first human baby and the Platypus baby will be the first animal baby in the neighborhood.