Ghost

Castle is embarrassed when Lu mocks his high-top shoes, which aren’t designed for running. However, when he cuts the tops of the shoes off, Shamika and the rest of the class laugh at them. Rather than be laughed at again for his shoes, Castle makes the drastic decision to shoplift the silver bullets from the sporting goods store. He is willing to steal, even though he knows how his mother and Coach would feel about it, rather than ask for help in getting the shoes. 

The silver bullets represent Castle’s desperation both to be accepted and to be left alone. He wants to look cool, and he wants shoes that will help him perform at a higher level, but the shoes also represent the absence of mockery for him. When Castle is laughed at, particularly when the laughing is centered on Glass Manor and poverty, he fights. He believes the silver bullets will help keep him out of fights. 

The shoes also symbolize Coach’s unwillingness to compromise ethics in favor of performance. He would rather kick Castle off the team—if he didn’t apologize—than have Castle help the team win with stolen shoes.