How It All Goes Down
To be honest, not much action actually happens in this novel. Maybe that's because the whole book only spans about three days. If you're thinking, "Wow—those must be some pretty significant days," you're totally right. Over the course of the three days, M.C. has to figure out whether or not he's going to leave his home—the only home and place he's ever known—in the Appalachian Mountains. It's a pretty major decision in general, especially for a thirteen-year-old boy.
The Problem
Why is M.C. thinking of leaving? Because even though Sarah's Mountain is his family's mountain, going way back to the days of slavery, and even though he loves the mountain like it's his mother, M.C. finds out that the spoil-heap above his house is sliding down and will probably destroy him and his family. All the strip-mining on the mountain has made the mountain an unstable place to live.
Stranger #1: The Old Man
Who tells him this? James K. Lewis, a stranger who's passing by the region and taping the songs of each region for posterity's sake. But M.C. doesn't realize that James is just a collector; he believes that James is going to make his mother Banina famous by recording her voice and turning her into a professional singer.
Of course, that's not what happens. James comes by and records Banina's voice, but by the end of the book, he lets M.C. know that he can't save M.C. and his family.
Stranger #2: The Girl
James isn't the only stranger in the book who impacts M.C.'s life in a major way. M.C. runs into a girl, slightly older than he is, called Lurhetta Outlaw (yes, that is her actual name). Lurhetta shows M.C. what a tough, independent girl is all about—she's traveling and camping on her own, which she does regularly every summer.
Lurhetta also shows M.C. how narrow-minded and prejudiced his family—especially his father—is about the other people who live around the mountain: the Killburns. Even though M.C. is friends with one of the boys from the Killburn clan, his father has banned him from bringing Ben around the house or even playing with Ben. So everything M.C. does with Ben is on the down low.
Of course, M.C. completely falls for Lurhetta (it's not like he even gets to see people outside of his family and Ben since he never leaves the mountain). But Lurhetta ends up leaving without a trace. Except, that is, her knife.
The Solution
She leaves her knife behind for M.C., which M.C. uses to start building a wall. And that's how the book ends.
M.C.'s a changed guy. He decides to stay on the mountain and fight for his home by building a wall between the house and the sliding spoil-heap.
See what we mean? Not much happens, but at the same time, a whole lot does: M.C. grows up.