The "Red Death" of the title is described as a particularly lethal disease whose symptoms include sharp pains, dizziness, profuse bleeding, and red stains on the bodies and faces of the victims. The contagion causes death within thirty minutes of infection, and consequently any sign of the red stain on a man causes him to be shunned by the populace. Although the disease is running rampant through his country, Prince Prospero remains oddly happy and carefree and invites a thousand of his healthy noble friends to join him in hiding from the disease in his abbey, which he then locks away from the outside world. He stocks the abbey with enough food to survive and leaves the surrounding country to its fate while holding wild parties within the building.
After five or six months, Prospero decides to hold a grand masked ball, which he holds in the seven rooms of an imperial suite. Instead of having the suite form one long hall, Prospero has the apartments segregated by sharp turns, and tall stained glass windows on each side of the room look out into the surrounding corridor. Each room features a different color, which matches the color of the window: the first room is blue, the second purple, the third green, the fourth orange, the fifth white, and the sixth violet.
The seventh room, however, is slightly different in that although the dominant color is black, the windows are blood red. The lights shining through the window from the corridors creates such a ghastly effect in this room that most of the guests avoid the room altogether. In this apartment is also a giant ebony clock, whose pendulum swings ominously and whose hourly ringing is so disturbing that it invariably disconcerts the musicians, dancers, and other revelers, causing everyone to pause until the chimes fade away, at which point everyone nervously resumes their actions.
Other than the unnerving seventh room, the ball is boldly and wildly decorated in a way that hints at Prospero's potential madness. The masqueraders' costumes are similarly wild, almost to the point of grotesqueness, and the party is described as "a multitude of dreams," despite the regular interruption of the gaiety by the ebony clock. All the apartments are crowded except for the seventh, and the ball continues until the stroke of midnight.
At midnight, when the clock strikes twelve times, a masked figure appears whose costume arouses emotions in the crowd that range from surprise and disapproval to terror. He stands out even in the gaudily dressed crowd because he is dressed as the Red Death. The tall, thin figure wears funeral garments marked with blood and a mask that resembles a corpse with the disease's characteristic red stains. Despite their debauchery, the crowd is stunned rather than amused by the costume, and, from the blue room, Prospero angrily demands into the silence that the figure be seized, unmasked, and hanged.
The prince's courtiers begin to move towards the masked intruder, but the figure begins to slowly walk towards Prospero, and everyone in the crowd is too afraid to grab him. By the time he reaches the violet room, Prospero becomes enraged and ashamed of his temporary lack of courage, and he rushes through the six rooms towards the masked intruder, wielding a dagger. At first the intruder retreats towards the seventh apartment, but when Prospero approaches the figure at the end of the violet room, the latter turns to face Prospero, who drops the dagger as he falls dead to the floor on the black carpet of the seventh room.
In despair, the crowd finally swarms around the unmoving figure of the Red Death, but they realize to their horror that there is no tangible body underneath the figure's mask and funeral garments. The revelers realize that the Red Death has finally caught up with them "like a thief in the night," and one by one, all of the partygoers fall, despairing and dying, to the floor. As the last of the guests dies, the ebony clock ceases to work, "and Darkness and Decay and the Red Death held illimitable dominion over all."
"The Masque of the Red Death" is in essence a story about the human desire to avoid death and the ultimate futility of such avoidance. Prince Prospero's name recalls both the term for wealth and the Shakespearean magician of "The Tempest" whose duchy was usurped, and he uses his wealth to give up his rule over his land and to flee death by shutting himself away with a thousand of his noblemen. Thus Poe shows him almost immediately to be fatally flawed, as he remains happy and carefree despite the decimation of his kingdom, showing a fundamental disconnect between his emotions and the needs of his people. His happiness does not result from innocence so much as a desperate fear of sadness and death, and the apparent sinfulness of his actions is ironically underlined as he shuts himself into a religious abbey, which Prospero has protected with iron in the hopes of keeping away the consequences of his wrongdoings.
We can easily view the Prince's masquerade ball as an allegory for the inevitable procession of life into death. Prospero's seven rooms seem to represent the seven decades of his life, as the first room is located on the eastern side of the corridor, a direction that has commonly been associated with the sun rising and hence with the beginning of life, and the seventh room is located on the far west side of the corridor, in the direction of death and of the setting sun. Furthermore, the seventh room is clearly associated with death, both through its black color and through the red coloring of the windows, which refer to blood and to the ever-present aura of the Red Death. When faced with the figure of the Red Death, Prospero freezes at first in the first room and then plunges towards the seventh room, where he dies, caught at last by the Red Death.
The structure and contents of the rooms at the masked ball hint at the failure of the revelers to entirely forget the presence of the Red Death, although they attempt to defeat their fears by celebrating and engaging in various forms of debauchery. As Poe notes, the stained-glass windows of the seven rooms do not perform the usual task of showing the outside environs. Instead, they merely look into the surrounding closed corridors, indicating the willful ignorance of the partygoers, who have shut themselves away and refuse to face the truth. However, the cheer of the masqueraders is regularly and forcefully interrupted by the clock from the room of death, which tolls every hour and reminds the courtiers not only of death but also of the passage of time.
Just as the clock strikes midnight, indicating the end of the day and perhaps consequently the end of a life, the figure of the Red Death appears as the final omen of death. Like the clock, he is able to disturb the courtiers because of the reminder that their gaiety is merely a thin shield for their fear, and he accordingly induces fear. Prospero's orders to seize, unmask, and hang the figure merely emphasize three aspects of death that cannot be altered. To seize death would be to prevent it from doing harm, to unmask it would be to show its secrets, and to hang it would be to kill it. It is clearly impossible to do any of these three, and accordingly, when the crowd does overcome its fear and tried to grab hold of the mummer's figure, they find nothing to grasp.
The title of the story, "The Masque of the Red Death," is in and of itself a play on words. A masque is a costume ball such as that in which the events of the tale take place. However, the fact that the Red Death appears masked in the seventh room is of special significance beyond the fact that he is attending a masquerade. The mask shows the image of a corpse that has recently been stricken by the plague, but provides no hint of what lies under the mask. The fear of the unknown is a common theme in many of Poe's works, and the story suggests that humanity's ignorance of the nature of death is a major contributor to its fear. In the case of the reveling courtiers, their ignorance results as much from their disconnect with the common people who have suffered from the Red Death as it does from the lack of human knowledge concerning death. The masque is both a response to their fear and ignorance as well as the cause of their destruction.