Note: Because Salinger wrote "Franny" and "Zooey" as separate stories, each has a plot that is complete in and of itself. Because of this, we chose to analyze the plot of each story separately. As an exercise, you could always look at the novel as a whole and determine the different plot stages this second way. Let us know if you discover anything interesting.
We get enough background info to know that these two are together. We also start disliking Lane. The author actually sets us up to take Franny's side by exaggerating and caricaturizing Lane's arrogant qualities.
And that will sure throw a monkey wrench into your relationship. It soon becomes clear that Franny is no ordinary college gal. She's having some sort of personal crisis, and Lane is too self-absorbed and materialistic to notice.
When Franny goes into the bathroom and sobs her eyes out while clutching this tiny book, we know we're dealing with more than typical relationship problems. There's a spiritual/religious element to consider, too, which makes for our complication.
We've been building toward this moment since the start of the story in the sense that this mysterious little book has been mysteriously popping up all over the place with no explanation (or even title). We know it matters, because of all the foreshadowing, but we don't really know what it is – until this moment. It's also fitting that this explanation is at the center of the story's plotline, since it was the impetus for Franny's breakdown in the first place.
A collapsing faint makes for good suspense in any tale. Why did she pass out? Will she be OK?
Apparently she's undernourished, but other than that, all systems are go. All that suspenseful worry for nothing.
As we suspected, that little book Franny was carrying around was no incidental paperweight. She's clearly taking this stuff seriously, and we conclude that it has much to do with her dissatisfaction with college life and her relationship problems with Lane.
Putting the "author's introduction" aside, the real story begins with Zooey, taking a bath. We get all the background info we need about the Glass family via Buddy's letter, his narration, and informative footnote.
The conflict has mostly to do with Mrs. Glass's request that her son speak with Franny. Since the novel as a whole is the story of Franny's spiritual crisis and eventual resolution, the conflict in "Zooey" has to do with his role in resolving this central crisis.
Zooey does try to talk his sister out of it – but he ends up hurting more than helping. The plot is moved forward as the central crisis is now even further from resolution.
The climax of the story is the moment when Franny snaps out of it already. She has a spiritual epiphany while talking with Zooey, which we can detect in her manner and movements. She can't even hold the phone on account of the joy she's feeling. This is the moment we've been building toward in "Zooey" but also in Franny and Zooey as a whole.
No suspense stage here. Since we already know that Franny is out of crisis-mode, we're not too worried about her spiritual or physical well-being. We're just ready to move right into the denouement and conclusion, which, as you'll see in your text, come in immediately after the climax.
The brevity of this stage betrays its intensity. There is a serenity and beauty to be found in just this short single passage, "A dial tone, of course, followed the formal break in the connection. She appeared to find it extraordinarily beautiful to listen to, rather as if it were the best possible substitute for the primordial silence itself. But she seemed to know, too, when to stop listening to it, as if all of what little or much wisdom there is in the world were suddenly hers" (Zooey.8.80). Franny has found peace.
"Quietly" is the key word here. Compare this conclusion to that of "Franny," when she lies on the floor mouthing the words of the Jesus Prayer. There are a few different ways to interpret this, and we talk about them in "What's Up With the Ending?" What we do know, either way, is that Franny's crisis has been resolved.