Small reveal: After Harlon and Steve find the dog in the Dumpster, the original plan is for Steve to adopt it. But Steve’s apoplectic parents refuse to let him keep it. Instead, Harlon brings it home instead, and is promptly told to take it to the pound. Later that same night, there are sirens around Steve’s house. Something terrible has happened there—a suicide is implied—but Harlon can’t get any answers from police. He’s reassured, however, when Steve suddenly appears by his side, shaking his head over not being able to keep the dog. On the eve of the shooting, Harlon goes back to Steve’s house looking for a partner, but his parents are shocked and appalled by his request, because their son did indeed commit suicide. The Steve Harlon was seeing was a hallucination, much like the comic-book characters that talk to him. 

Big reveal: The whole thing could be a dream. The film observes Harlon leaving his car with the rifle and shooting several people in the school, including the teacher who tried to help him and the jock who bullied him. But it ends with a shot that has him back in his car, perhaps just imagining the shooting without actually going through with it. Did he or didn’t he? Dunno. Roll credits.