Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Exposition
It's All Fun and Games 'til Someone Invents a New Religion.
We meet Jason and Shin in their current world—they are snail-hunting BFFs, smart and smart-alecky (on Jason's part). The social lines are clear, with Henry the bully on the other side. The creation of the church goes smoothly as they include Dan and cute-as-a-button Magda.
Rising Action
It's Hard to be Pope
Jason invites Henry to be part of the CTG. This is kind of a betrayal to Shin though, because Jason hasn't discussed it with him and Henry bullies Shin a lot. Jason starts counting the lies and manipulation that are necessary to lead his growing religion. When the whole gang climbs the tower, but Shin is too terrified to make it, we know there will be fallout in terms of the Jason-Shin relationship. We're also a bit worried about Shin's fervor for Chutengodianism and the bible he is "channeling" from the Ten-legged One.
Henry falls—ouch—so everyone gets punished, the CTG fractures, and Jason is jealous of Magda's apparent interest in Henry.
Climax
Tower Climb 2.0
Since Jason has already said his water tower climbing nights are over, we naturally know he'll be up again. And in the worst possible conditions—during an electrical storm. The CTG, Jason's whimsical creation, has become a driving, delusional force for his best friend, so it's Jason's responsibility to get Shin to safety. The battle wages externally with wind, rain, lightning, and thunder, and internally as Jason realizes that Shin has lost his grip on reality. Then he has to betray his friend yet again by calling the cops on him.
Falling Action
Crisis of Faith
Shin is hospitalized in the psych ward, Dan wants nothing to do with Jason, and Magda's a no-show at Teen Power Outreach meetings. To top it all off, Jason is grounded and will be doing community service into his eighties.
Resolution
One Last Blow to the Head
Although Jason isn't permitted to see Shin, he sneaks a visit. The visit doesn't go quite as Jason hoped, but at least the two friends are talking. Plus Jason's dad signs off on him being old enough to make his own choices when it comes to religion, to follow his own road of faith—or lack thereof—so no more forced church for our main man.
Henry cracks Jason on the head again, which leads Magda to reach out with flowers and a card. (We've got our fingers crossed for you, Jason.) Jason realizes Shin's right that you can't understand something if you don't believe in it. "You can't really understand what it means to be Catholic (or Muslim, or whatever) unless you have faith. And you can't understand algebra unless you believe in numbers" (31.49). As the book ends, Jason envies those who believe in something—it's lonely believing in nothing.