A thirteen-year-old kid, Brian Robeson, is flying to visit his dad after his parents' divorce. The pilot has a heart attack and dies, and the plane crashes into a lake in the Canadian wilderness. Brian survives, alone with nothing but the hatchet his mom gave him.
It's basically a step-by-step manual on not dying, told through a story. He figures out how to make a shelter, get a fire going, find edible berries, and fend off animals like a moose and a porcupine. The hatchet is his only tool, and he uses it for everything—splitting wood, making sparks, even building a raft later. The mental stuff is heavy, too; he's haunted by the "Secret" about his mom's affair, which comes back during a low point.
After a tornado wrecks his camp and he finds the plane's survival kit in the lake, a rescue plane finally spots him. The whole book is just that raw, stripped-down fight to exist, where every small victory, like catching a foolbird, feels huge.