Sarty is the ten-year-old hero of the story. We see everything through his eyes. At first, it seems like Sarty is being moved through the events of the story by his father, who controls everything. As things progress, we see Sarty moving things himself. It's true that Abner does most of the things that drive the physical action, but Sarty's internal conflict drives the psychological action. By the end of the story he steals Abner's role as principal actor by alerting de Spain, and then turning his back on the scene.