Big Bird reveals to Snuffy that something special is going to happen today: all his grown-up friends will finally get to meet his best friend face-to-face! Big Bird explains how tired he is of hearing everyone humor him about his "imaginary friend."
In the early morning, Snuffy stops by Big Bird's nest, unable to sleep from the thrill of meeting everyone yesterday. A thought then occurs to him - he wonders if it really happened, or if he just imagined it.
Snuffy wants to introduce Big Bird, Maria, Bob, Luis and Gordon to his new friend, but isn't sure how to do it since he just recently became friends with the grown-ups himself. Bob witnesses Snuffy playing a Snuffleupagus instrument called the "harpmonica."
Gordon is sitting on the stoop of 123 Sesame Street and reminisces with the viewer about a time where he waited all day for Mr. Snuffleupagus. He decides he could take a walk over to Snuffy's cave so he could get to know him better.
Telly Monster speaks in whispers as Gordon is asleep nearby in the yard, having stayed up late grading papers. The two were supposed to have lunch together, but Telly doesn't see how this can work if Gordon is sleeping.
Bob comes across Oscar's trash can, which has now been converted into an ice creamery. Oscar advertises his nine different flavors, all beginning with the letter S. Oscar recruits Grundgetta to help attract customers to the stand.
Snuffleupagus wrote his name today in Snufflegarden, but because he writes so big, he had to use four cards. He shows them off to Big Bird and the kids, who make several attempts to put them in the right order.
Telly goes to Hooper's Store, but finds the door is locked and the glass from the window is missing. He calls David over, who explains that some kids playing baseball accidentally broke the window. Telly helps David measure the size of the window.
The Honkers are in deep honk conversation when they notice the viewer and start honking even more and waving. Olivia comes by and asks what they're doing; they're so noisy. She wishes she could understand honk.
After an encounter with Forgetful Jones, Maria imagines what it would be like to be just as forgetful as he is. Back in the present, David arrives to remind Maria about their lunch date.
Bob plays “Pop Goes the Weasel” with two kids and Forgetful Jones, who plays the cymbals off-cue. Bob instructs him to play after the word “fun,” but he does so when Susan stops by and asks if she can join the fun.
As Olivia rushes to work, she bumps into Bob and his friend, who Olivia shows signs of interest in. When they pass Oscar's trash can, Oscar is introduced to Bob’s friend, Bernie (a piano tuner).
Oscar acts like a pirate in preparation for a bout of sailing with his pet elephants. Their ship, the S. Discontented, floats in the pool and the mast sticks out from the top of the can.
Bob and Luis encounter Oscar training some live dogs in his Grouch dog training school; he’s training them to disobey his commands. Bob questions this whole concept, and Oscar reminds him of the difference between Grouches and humans.
The Count tells the viewer that today, they're going to learn to count grown-ups. He calls over Bob, Susan, Maria, David, and Mr. Macintosh, who are all rather busy, but allow themselves to be counted for the sake of the viewer.
The cast prepares the street for a special occasion, decorating with a large banner, balloons and food. Forgetful Jones can't remember what's going on, so the others remind him that his favorite country singer is coming to visit Sesame Street today.
Susan, Olivia, David, and Bob prepare to have a picnic in the park for an outdoor concert. Grundgetta brings them something else they might need - her portable radio, which broadcasts a Grouch weather report indicating rain.
Bob finds Oscar typing away in his trash can. Oscar, wearing a writer's outfit, tells him that he's working on a play about trash to be performed today on Sesame Street. Bob asks to read it and Oscar allows him.
Telly Monster and Big Bird are fighting over who gets to read a book in Big Bird's nest, tugging on each end until it tears in half. They apologize to each other and decide to each read their own half.
On Ask Oscar, Telly reads a letter asking about the importance of listening. Oscar drives Telly crazy by blatantly paying little attention to everything he says, forcing Telly to repeat the details over and over.
Luis gives Telly Monster a plan on how to get Oscar the Grouch to help show one of today's letters - R. Telly loudly begins his talk to get Oscar's attention and asks Oscar not to help at all. The reverse psychology works.
Maria welcomes the viewer, then encounters Big Bird teaching a baby Honker to honk the alphabet. Big Bird recites it one part at a time in the form of "The Alphabet Song," and with Maria's help they get through the whole song.
Slimey has had a long day of activity, so Oscar weighs him on a scale. David notes that Slimey weighs 4 ounces, which isn't accurate because he's holding a balloon, a backpack, and a hockey stick.
At today's Grouchketeer meeting, Oscar presents a lesson on the letter S. On his Grouch computer, he's loaded a program that shows grouchy images of S words when the S key is pressed.
Snuffleupagus shows Big Bird his outfit for a pageant about the alphabet at Snufflegarden, where he's playing the letter X. He sings his part in the show, then heads off.
Piri wants to ask David for a part-time job at Hooper's Store. Oscar demonstrates how he should make the ask, with Telly's help. He gets face-to-face with Telly and loudly demands a job.
Big Bird and Snuffy declare today as "Best Friends Day," and plan to celebrate together with a picnic in the park. Big Bird is eager to get started, but Snuffy reminds him to first pick up their lunch at Hooper's Store.
Everybody on Sesame Street prepares for Miles' arrival in their own ways. A deliveryman drops off extra diapers and baby food for David at Hooper's Store, while Maria and Luis set up a play pen by the tire swing.
Susan and Gordon welcome the viewer to Sesame Street, and explain their process of baby-proofing the apartment in order to keep little Miles safe. They're taking any breakable objects and placing them on the shelf out of Miles' reach.
Susan's parents arrive from Michigan to see Miles. They are eager to see their grandson for the first time, but he is finally sleeping. Miles' grandmother Dorothy wants to sneak a peek while he's asleep.