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 (Initial Situation)
We meet the book's main character, the kid, who runs away from home when he's only fourteen years old. He spends a few years wandering the American Southwest, getting himself shot and stabbed fairly often. He survives long enough to get himself enlisted by an American militia that wants to go into Mexico to show the Mexicans who's boss. But the group is barely in Mexico for 48 hours before a group of Apache warriors demolishes them. The kid barely gets away and eventually gets himself thrown in Mexican prison for being connected to the militia. And this is just the beginning of the story.
Rising Action (Conflict, Complication)
The kid finds himself bailed out of jail by a guy named Judge Holden, who he met briefly back in the States before he (the kid) and the American militia travelled into Mexico. Well it looks like Judge Holden and a man named Glanton have a contract with the Mexican government to get some Apache scalps. Seeing as how it's better than jail, the kid joins Glanton's group and starts killing Apaches for a living. It's always clear, though, that the kid doesn't like to kill people for no good reason—and we certainly don't blame him. Judge Holden eventually realizes this and criticizes the kid for being weak.
Climax (Crisis, Turning Point)
Eventually, a group of Yumas catch up with Glanton's group and slaughters nearly everyone in it. The only ones to escape are the kid, Judge Holden, and a few other guys. Immediately after the attack, the kid has to deal with being shot at by Judge Holden…and this won't be the first time. Holden, you see, thinks that the weaklings of the world need to be cleared away to make room for the strong. He thinks that kid is weak because the kid has always shown hesitation in killing defenseless women and children. We guess they didn't call it the Wild West for nothing.
Falling Action
The kid eventually escapes Judge Holden. Shortly afterward, he sees the other survivors of Glanton's crew being hanged, which makes him and Holden the only surviving members of Glanton's group. Ten years after the Yuma attack, the kid runs into Holden in a bar. Holden tells the kid how disappointing he always was. When the kid heads out to use an outhouse, the judge is waiting for him inside. He pulls the kid in and we never hear from the kid again. The judge has probably killed him, though we don't know for sure.
Resolution (Denouement)
After he's finished with the kid, Judge Holden returns to the tavern and starts up a big dance. Even though he's seven feet tall, the judge is an incredibly agile dancer. He dances around, telling people he never sleeps and that he'll never die. Come to think of it, there's plenty of evidence to suggest that the judge is some sort of supernatural creature. But McCarthy never confirms this one way or the other. You're probably used to hearing that by now.