Who is Jim Donnini from Welcome to the Monkey House and what is their importance?

Jim is a 15-year-old kid from the wrong side of the tracks. His mom dies. His dad remarried Quinn's sister, then left him with her. Quinn's sister put him in foster care, then sent him to live with Quinn. Jim has responded to all of this by becoming completely apathetic. Nothing gets in. He seems to only take joy in polishing his boots. He ignores Heinholz's friendly advances, blowing smoke rings in his face instead. Jim takes some perverse joy in destroying the school. He says the place need to be turned on its side. This argument crumbles, though, when Heinholz hands Jim his trumpet. Jim is not sure what do if an adult is not mad at him. Jim further buckles when Heinholz removes his boots. Jim is shaken to the core.