Big Bird helps Snuffleupagus train for the NYC Marathon while the Sesame Street crew cheers on Gordon. Despite Snuffy's repeated tardiness at every checkpoint, Big Bird patiently waits for his friend to finish the race, even sleeping in the park overnight. Gordon and Susan eventually return to help push their car home as thanks for Big Bird's loyalty.
Big Bird wakes from a nightmare and struggles to fall back asleep despite help from Maria, Susan, and the Honkers. Maria falls asleep mid-relaxation advice while Susan's bedtime stories don't help, but the Honkers' rendition of "Brahms' Lullaby" finally gets Big Bird to sleep.
The cast sings about circles while Forgetful Jones accidentally buys basketball sneakers instead of horseshoes for Buster the Horse. Big Bird performs a poem about the letter S with kids acting out related words, though Mr. Snuffleupagus doesn't appear in time for the conclusion.
When Big Bird eagerly presents drawings he made of his adult friends, he's devastated to learn that Mr. Hooper has died. The adults gently explain what death means, reassuring Big Bird that they'll help care for him and David will run the store. Big Bird tearfully says goodbye to Mr. Hooper's portrait as his friends comfort him.
Maria teaches Forgetful Jones to remember by writing things down, asking him to jot down the number seven and other information. However, Forgetful ends up with piles of papers for everything he wants to remember, leaving him buried under his own notes by evening.
Oscar proudly teaches the Grouchketeers his own "Grouch alphabet" starting with D for "dirt" and "dust." After Gordon finally delivers the promised three bags of dirt (cleverly tiny ones), Oscar reluctantly agrees to teach the correct alphabet despite being outwitted.
Big Bird leads imaginary elephants into a pretend closet to teach addition while confusing Luis. Oscar demonstrates that objects don't need to be in one place to count correctly, then gets annoyed at teaching something nice.
Forgetful Jones plays cymbals off-cue during "Pop Goes the Weasel" until he gets the timing right. The group examines autographs on casts and learns that worms are invertebrates, while Big Bird teaches others to put toys away.
Big Bird finds a "Se Habla Español" sign blown by the wind to a tree and tries mailing it to Puerto Rico. Oscar demonstrates subtraction with bowling balls while Forgetful Jones discusses the word "love" with Clementine.
Gilbert and Sullivan sing "The Letter B" while Oscar plans a vacation with predictably Grouch packing. Dr. Nobel Price drops his teddy bear repeatedly and declares he's discovered gravity, ignoring Olivia's attempts to explain it.
The gang prepares a bath for Barkley using an inflatable pool and increasing amounts of water. When Snuffleupagus arrives thirsty and drinks the entire tub, nobody believes Big Bird's story until later when they finally bathe and dry off the dog.
Oscar throws an eclipse party with his Grouch telescope while Telly panics about the moon disappearing and prepares with a protective outfit. Maria scolds Oscar for tricking Telly, allowing him to yell at the Grouch before they reconcile.
Oscar hosts Monster on the Spot radio while dismissing various sounds until Telly's complaining becomes "beautiful." When Dr. Nobel Price accidentally breaks his picture, he invents a puzzle by putting the pieces together with Olivia's help.
Oscar runs a dog training school teaching dogs to disobey him, adding "don't" to commands when his initial approach fails. Snuffleupagus confirms his reality while Gordon unknowingly plays a duet with Snuffy thinking it's Big Bird.
Bob and Oscar quarrel over the letter Q while Big Bird teaches about cooperation. Max brings his broken wagon to be fixed, refusing to replace it despite being missing every part except the handle.
The gang participates in various educational activities exploring letters, numbers, and skills together.
Short educational segments teach letters, numbers, and social skills through character interactions.
Gladys the Grouch cow needs a new cowbell, and the Sesame Street community helps her find or create a replacement for her beloved noisemaker.
Snuffleupagus becomes ill and Big Bird cares for him while friends visit to check on his condition and offer support during his recovery.
Characters engage in educational segments and interactive activities exploring various learning topics.
Country music star Polly Darton visits Sesame Street, performing songs and spending time with the characters in musical celebration.
Big Bird and friends explore rhyming words and their creative uses in stories, songs, and games throughout the episode.
Captain Vegetable arrives to teach the characters about healthy vegetables and the importance of proper nutrition.
Piano tuner Bernie arrives to fix Oscar's instrument but develops a connection with Olivia instead, exploring themes of unexpected romance.
The cast engages in educational activities exploring letters, numbers, and social-emotional learning concepts.
Telly Monster meets Snuffleupagus for the first time and reacts with his characteristic nervousness to the large, unusual creature.
The Sesame Street gang teaches a young baby Honker the alphabet letters in a mentorship focused on early learning.
Characters participate in educational segments and interactive learning throughout the episode.
Forgetful Jones attempts to run Hooper's Store but keeps forgetting customer orders and cash register procedures, creating humorous situations.
Telly struggles with a broken kite while Luis works on a picture, with both characters learning about problem-solving and cooperation.