The storytelling strategies employed in the passage are character revelation, plot advancement, suspense, surprise but not dramatic irony.
Most fundamentally, Harry’s ruthlessness is revealed when he tries to shoot Tom. After Tom refuses to help Harry, Harry “tries to fire the gun” (130). This action shows how ruthless Harry is because it demonstrates that Harry will do anything that is necessary to escape without hesitation even though it is killing his own brother.
With the revelation of Harry’s ruthlessness, the plot advances closer to the breaking point in which Harry dies. When Harry points the gun at Tom, Tom does nothing to prevent Harry because Tom is actually testing Harry to see if Harry will shoot. Eventually