In Edgar Allan Poe's "The Masque of the Red Death," who is the masked figure who shows up at Prince Prospero's ball (the intruder)?

It is safe to suggest that the masked figure who menacingly appears in the midst of Prince Prospero's ball in Edgar Allan Poe's short story The Masque of the Red Death is an intruder. If he were a figure in a H.H. Munro (Saki) story, he might be labeled an "interloper." 

In Poe's story, the "Red Death" is a reference to the plagues that devastated European populations during the medieval period. While the Black Death,...

It is safe to suggest that the masked figure who menacingly appears in the midst of Prince Prospero's ball in Edgar Allan Poe's short story The Masque of the Red Death is an intruder. If he were a figure in a H.H. Munro (Saki) story, he might be labeled an "interloper." 

In Poe's story, the "Red Death" is a reference to the plagues that devastated European populations during the medieval period. While the Black Death, bubonic plague, is better known, Poe's use of "Red Death" was more likely a reference to the Small Pox epidemic that struck New England during the early 17th century or to the epidemic that hit Europe in the 18th century. In any event, "Red Death" is a reference to Small Pox, and it is from that horrendous disease that Prince Prospero and his invited guests are hiding within the confines of his castle. Poe meticulously describes the details of the suite of apartments inside Prospero's abbey and it is into these carefully if disturbingly-decorated rooms that the story's climactic scenes occur. First, however, Poe's unseen narrator describes the revelry that ensues within the castle walls while the less-fortunate die horrible deaths outside his castle gates. The prince has deluded himself that he is safe from the plague ravaging the countryside, but it is the following passage from The Masque of the Red Death that shatters Prospero's tranquility:

" . . .before the last echoes of the last chime had utterly sunk into silence, there were many individuals in the crowd who had found leisure to become aware of the presence of a masked figure which had arrested the attention of no single individual before."

This "masked figure," of course, is Death, come for the avaricious monarch, a not so subtle reminder that brick and mortar could not shield the prince from the plague decimating is subjects beyond the castle walls. This, then, is the nature of the "intruder."