Our protagonist, Holden, discovers that his roommate, Stradlater is getting ready to go on a date with Jane Gallagher, Holden's neighbor, and friend. Holden knows she is a sensitive soul who has had a difficult home life and may have possibly been molested by her step-father. Jane also endears herself to Holden by her little quirks of idealism and artistic flare. For example, when playing checkers, Jane prefers to keep her Kings in the back row just because they look good there. She also reads "good books". Holden also knows that Stradlater will fail to treasure Jane because he is a womanizing creep and will most likely just try to score with her. This possibility is giving Holden a lot of anxiety.

While Stradlater is primping for his date, (Holden tells us that Stradlater is a vain slob), he asks Holden if he can do him a big favor. Holden talks to us again, asking us if we ever notice that vain, big shot-type people always seem to need a big favor. This will be the second big favor that Stradlater asks of Holden. The first was asking to borrow Holden's jacket.

At any rate, the big favor that Stradlater needs is for Holden to do his assignment for his English class; which is to write a descriptive essay. During this time, Stradlater also compliments Holden's unique red hunting cap, just to flatter Holden into doing his assignment. This ploy works because, despite Holden's negative feelings for Stradlater, he agrees to do the assignment for him.

When Jane arrives for her date with Stradlater, Holden keeps saying that he is going to go downstairs and say hello to her. But he does not do this and instead tells Stradlater to be sure and send his regards though he knows Stradlater is too self-involved ever to remember to do that. Holden's one comfort is that he has discovered that Jane only signed out of her dorm until 9:30 PM. Therefore, Stradlater complains, they won't be able to do much.

When Ackley comes back in the room, Holden is, for once, happy to see him, even though he is repulsed by Ackley's constant pimple picking. At least, Holden tells us, Ackley can distract him from worrying about what will happen on Stradlater's date with Jane.

It is Saturday night, and Holden reveals to us another phony thing about his school. They serve steak every Saturday night at Pencey, for the sole reason of impressing the parents who visit on Sundays, and will, undoubtedly, ask their sons what they ate for dinner the night before. Steak is very impressive.

When Mal Brossard and Holden decide to take a bus into town for the night, Holden convinces Mal to let Ackley accompany them. Holden worries that otherwise "the kid will just sit in the dorm all night and pick his pimples." Agerstown is boring, but they make the best of it by playing pinball and eating hamburgers, returning to the dorm by 8:45 PM.

Holden gets to work on writing Stradlater's descriptive essay for him but is not motivated by describing a living room or a house, as Stradlater suggested. Holden decides to write about the left-handed fielder's mitt that belonged to his brother, Allie. The glove is interesting because Allie wrote poems in green ink all over the glove. The reason Allie did that was to be able to read them when he got bored standing in the outfield. It is here that Holden tells us that his brother, Allie died of Leukemia. Allie died in 1946, and from this timeline we can assume, that Holden is telling us this entire story in 1950. Allie died when he was only eleven years old, and Holden was thirteen. Allie's death a major factor in understanding Holden and why he feels so disillusioned with everything and is so protective of children and people whom he considers innocent. Holden feels powerless because he could not protect his younger brother from death. The left-handed mitt is a major symbol in this novel representing the fragility of the dreamer and all sensitive, intuitive people in this harsh world.

It should be apparent to Holden that Stradlater is too much of an oaf to appreciate the beauty of Holden's choice to describe the mitt. Holden brings the mitt with him to Pensey, as it is very precious to him because it was cherished by his little brother, who died too soon. Holden describes his little brother as being "terrifically intelligent." He also says that Allie was a very happy little guy who, he tells us, "used to laugh so hard at something he thought was funny that he just about fell off his chair." He says, "People with red hair are supposed to get mad easily, but Allie never did, and he had very red hair." Holden loved his little brother, and it is obvious that his early death has truly broken Holden's heart.

Holden reacted to the death of his younger brother, by going into his garage and smashing every window and thus, breaking his hand, he tells us. He even tried to smash all the windows in the car, but his hand was already useless. Holden says he still cannot make a good fist, but he doesn't care because "it's not like I'm ever going to be a violist or something."

Holden is still awake when his roommate, Stradlater returns from his date with Jane. He returns the jacket that he borrowed from Holden. He reads the descriptive essay that Holden wrote for him. Naturally, being an insensitive clod, Stradlater says the composition should have been about a room or a house and not about some dumb baseball mitt. He says that Holden always gets everything "ass-backwards", Holden reacts to this remark by tearing up the composition. Then he lights a cigarette because he knows his roommate hates it. Then he asks about Jane. Stradlater is clipping his toenails and avoids answering. So, Holden asks directly if he "made time" with Jane, but Stradlater still avoids answering. The thought that Stradlater may have had sex with his sweet, fragile neighbor, sends Holden into a fit of rage, and he tries to hit his roommate. Stradlater is much stronger than Holden, and pins him down and kneels on his chest. When he finally lets him up, Holden calls him a "dirty, stupid sonuvabitch of a moron." Stradlater punches Holden in the nose. There is blood everywhere, and Holden is sobbing on the carpet and keeps calling Stradlater a moron until Stradlater walks out of the room.

Holden puts on his red hunting hat and looks in the mirror. He observes that he looks pretty tough, even though he obviously lost the fight. He decides to go next door to Ackley's room. Ackley wonders why Holden has a bloody nose, but Holden doesn't want to talk about it; he only wants to play cards. Later, Holden asks if he can sleep in Ackley's room, but Ackley says no. Holden leaves after some time and decides to move out of Pensey that night. He decides he will just stay in a hotel in New York for a few days until it is time to go home at Winter Break. He has enough money saved because his grandmother sends him money about four times a year for his birthday, which she obviously forgets that she sent him and also confuses the date of his birthday. Holden also sells his typewriter for $20.00.

As he is leaving, Holden puts on his red hunting cap again, and yells down the hall "sleep tight, ya morons!" and this is the way Holden says goodbye to Pensey.