What does the mechanical hound symbolize in fahrenheit 451?

answer: common sense was the pamphlet that thomas paine used to convince reluctant americans to abandon the goal of reconciling with britain and to accept that independence was the only option to preserve their liberty.

in the story "marionettes inc," in the last line of the story, braling two is referred to by the narrator as the "someone." what does this new identifier imply and how does it add to the drama of the closing scene?