Just as the museum closes, Big Bird announces that he must stay behind to find Mr. Snuffleupagus. While the others search the entire museum for Big Bird (while avoiding a guard), he and Snuffy befriend Egyptian Prince Sahu, who has been trying to solve a riddle for more than 4,000 years so that he can finally join his parents. The boy prince claims to be under a spell cast by Osiris, the Lord of the Underworld, and asks Big Bird and Snuffy to help him find the answer to the question, "Where does today meet yesterday?" The three wander throughout the museum searching for clues from ancient Egyptian drawings, while the others examine masterpieces and art objects.
Other characters have their own unique cultural experiences: Oscar the Grouch stumbles upon a Roman and Greek statue display and sings about "the most beautiful trash" he's ever seen; Cookie Monster, reading a booklet entitled "Food Art," sings the title song about museum etiquette; Grover sings to a suit of Maximillian armor; and Bert and Ernie examine a portrait of George Washington.
- "Broken and Beautiful"
- "I Want to Be Your Friend"
- "Don't Eat the Pictures"
- "You're Gonna Be a Star"
- "Mothers and Children"
- Linda Bove as Linda
- Northern Calloway as David
- Loretta Long as Susan
- Sonia Manzano as Maria
- Bob McGrath as Bob
- Roscoe Orman as Gordon
- Alaina Reed as Olivia
- Aram Chowdhury as Prince Sahu
- James Mason as Egyptian Demon
- Fritz Weaver as Osiris
- Paul Dooley as Museum Guard
- Li Alexander, Jason Paul Janzer, Nadia Jones, Mika Kakizaki, David Zetlin-Jones, Andrew Cassese
- Caroline Kennedy (uncredited cameo)
- Frank Oz as Cookie Monster, Grover and Bert
- Jerry Nelson as Count von Count
- Richard Hunt
- Brian Muehl as Telly Monster
- Bryant Young
- Jim Henson as Ernie
- Caroll Spinney as Big Bird and Oscar the Grouch
- Martin P. Robinson as Mr. Snuffleupagus
- Director: Jon Stone
- Producers: Arlene Sherman, Tony Geiss, Lisa Simon
- Written by: Tony Geiss
- Music by: Dick Lieb, Stephen Lawrence, Tony Geiss, Chris Cerf
- Music Coordinator: Danny Epstein
- Music Assistant: Dave Conner
- 2nd Unit Director: Emily Squires
- Art Director: Victor Di Napoli
- Muppets by Kermit Love, Caroly Wilcox, Ed Christie, Don Sahlin, Noel MacNeal, Cheryl Blalock
- Production Stage Manager: Chet O'Brien
- Costume Designer: Bill Kellard
- Set Decorator: Nat Mongioi
- Audio: Blake Norton
- Sound Effects: Dick Maitland
- Executive Producer: Dulcy Singer