In "Roof Beam" we learn that Seymour commits suicide in 1948, several years after the action of this story takes place.
Buddy tells an anecdote about Seymour reading a "prose pacifier" to Franny when she was a baby.
Buddy goes to his brother's wedding in New York. It's hot and uncomfortable, and he also has pleurisy (a painful lung condition).
At the wedding, Seymour is a no-show. Buddy is elected to help people into the guest cars. After some time, he simply jumps into one himself.
Buddy meets the other guests in the car. He feels immediate kinship with the silent old man. He listens to the Matron of Honor complain about Seymour.
Buddy finds out that the old man is the bride's father's uncle and a deaf mute (he can't hear or speak).
The car's progress is halted by a passing parade. They try to go to Schrafft's to get a cold drink, but find that it is closed. Buddy invites everyone up to he and Seymour's apartment.
There is some discussion of "It's a Wise Child" because of the photographs Buddy has hanging on the walls.
After enough provocation, Buddy explodes at the Matron of Honor in his brother's defense. He then lets her use the telephone and goes into the bathroom to read his brother's diary.
He sees Boo Boo's message on the mirror, reads Seymour's diary, and then drops it into the hamper.
Buddy goes into the kitchen and downs an enormous drink.
Returning to the living room, Buddy hears from Mrs. Silsburn that Muriel (Seymour's fiancée) looks just like Charlotte Mayhew (a popular actress). This is overwhelming for him.
Buddy and the rest of the guests find out that Seymour and Muriel have eloped and everything is fine. The guests leave to go to the reception.
Buddy is left alone with the elder uncle, to whom he tells the story of Charlotte.
He reads the last entry in Seymour's diary and then passes out. When he wakes up, the elderly man is gone. He muses that he ought to send the burnt out cigar on to Seymour as a wedding present, with a blank piece of paper by means of explanation.
Buddy opens "Seymour: an Introduction" with two epigraphs, which he then discusses. He reveals that he is now 40 years old, a professor of English at a women's college, and somewhat of a hermit in that he lives alone in a house in the woods.
Buddy claims to be ecstatically happy as he begins this writing endeavor.
He discusses the stereotypical "sick artist" and the ways in which Seymour fit the bill. He also explores the way these Sick Artists die.
Buddy explains the difficulty he's had over the years in trying to write about Seymour. He discusses the other stories that are about Seymour.
Buddy explains that Seymour was a champion talker in their family.
He moves on to discuss Seymour's poetry at great length.
Buddy tells you what would happen if, after Seymour's poems got famous, students started coming around his place wanting to know more about the dead artist.
Buddy discusses his family's long history of entertainers.
He presents several of Seymour's responses to his [Buddy's] writing. The final piece is a long memo in which Seymour encourages Buddy to write what he would most like to read.
Buddy begins a long physical description of Seymour. He says that he had long wiry black hair. Seymour also loved their younger siblings and all their horseplay.
Buddy worries that he's writing this from a 40-year-old's vantage point.
He continues his physical description and reveals that Seymour had long fleshy ears and a completely unguarded face – he would smile when others were somber and vice versa, because he felt no social compulsion when it came to emotion.
In discussing Seymour's eyes, Buddy talks about the short story "Teddy."
Buddy moves on to Seymour's nose, which was large, like Buddy's own. Seymour's also had a bend in it from where one of the younger siblings accidentally hit him with a baseball bat.
He concludes that Seymour was an Attractive Ugly man. He goes on in detail about Seymour's hands.
Buddy discusses the way he and Seymour used to dress.
Buddy discusses Seymour's peculiar brand of athleticism.
Buddy tells the story of Waker's Davega bicycle and explains that he thinks of Seymour as his own Davega bicycle.
Buddy tells the anecdote about the marble. He briefly discusses Zen.
Buddy concludes that, although he is cynical about his students, teaching is the most important thing he does. It seems that he learned this from Seymour. He goes to bed.