Answer:
The clock in the story symbolizes the passage of time, which goes with the central theme of the inevitability of death.
Step-by-step explanation:
The central theme of Poe’s story "The Masque of the Red Death" is the passage of time and inevitability of death. While Prospero, the protagonist, and 1000 nobles hide in the abbey to escape terminal illness called the Red Death they decide to hold a ball under the masks. There are seven rooms, and the big ebony clock stands in the last one. The story describes the events, saying that every night “there came from the brazen lungs of the clock a sound which was clear and loud and deep and exceedingly musical” that musicians and the waltzers stopped their performances “and there was a brief disconcert of the whole gay company”.
This clock symbolizes the passage of time, and its hourly strikes are reminders of mortality. The symbolics is that the whole happy company is enjoying their time – meaning life – trying to use it as much as they can, but that every hour they are reminded that the time is passing, that they lost an hour, and, ominously, that the death is approaching. They all think they will not react the same the next hour – trying to make amends with the mortality – yet they are always shaken by the chiming. No one enters the seventh room where the clock is, which symbolizes the fear of realizing the mortality in fullness.
Finally, at the end, when the dark figure in a robe resembling a funeral shroud appears, Prospero and the noble are afraid, trying to attack him. Prospero corners the figure in the seventh room, and readers realize, as everyone starts dying, that this is the illness and death itself. The story narrates “whose tall figure stood erect and motionless within the shadow of the ebony clock” which symbolizes how death standing in the shadow of the time, always luring us.
In the last passage, we learn the clock has stopped, and that “the light of [it] went out with that of the last of the gay”. Therefore, the time stopped for all once they were all dead, and there; their story was over.