Entering through this particular entrance unsettles Coriolanus in part because, as he observed earlier, this was where poor people used to enter the arena. So going in here makes Coriolanus feel just as poor and powerless as the tributes—which, in many ways, he is. The Peacekeeper also seems to enjoy having this much power over Coriolanus; he seems unconcerned and unsympathetic to the fact that Coriolanus has every right to be afraid of going in here.