Mister Rogers arrives with a basket full of items which he uses to play a game where the items are matched with their appropriate cases and containers. The items include such things as a ukulele, a book, a brush, and a bowling ball.
Lady Aberlin stops by to tell Mister Rogers that singer (and her "pretend aunt") Mabel Mercer will be visiting the Neighborhood of Make-Believe. Lady Aberlin has been drawing a picture of Ms. Mercer.
In the Neighborhood of Make-Believe, Handyman Negri plays his guitar for King Friday and Queen Sara as they wait for Ms. Mercer. When Dr. Bill and Elsie Jean Platypus arrive, Dr. Bill starts to play his bagpipes but is promptly ordered by King Friday to stop.
Lady Aberlin arrives at the castle's S Room with a costume changer given to her by her "aunt" Mabel. It works by simply placing a block inside a small box. When Lady Aberlin tries the costume changer, her dress is immediately changed.
Everyone welcomes Ms. Mercer to the castle and is introduced to those waiting. After she sings Children Can and Just For Once, Ms. Mercer is joined by the others as they sing I'm Taking Care of You. King Friday proudly declares today to be "Mabel Mercer Day" in the Neighborhood of Make-Believe.
Back at the house, Mister Rogers recaps a wonderful day in Make-Believe as he cleans up the items in the kitchen.
For details, notes, and more screenshots from Episode 1041 of Mister Rogers' Neighborhood, visit the Neighborhood Archive.