Fear is a central theme in "The Masque of the Red Death," manifesting through the stark contrast between the world inside and outside Prince Prospero's abbey. The story explores the futile attempts of the wealthy to escape death and the pervasive dread that lingers even in their isolated refuge. Poe uses symbols like the welded locks, the ebony clock, and the personification of the Red Death to amplify the theme of fear, highlighting the inevitability of mortality and the terror it instills.

Outside the abbey, the mood is one of despair and horror as the Red Death ravages the land. The disease, characterized by bleeding and seizures, creates a terrifying atmosphere. Inside the abbey, however, Prince Prospero attempts to create a carefree environment, hosting a lavish masquerade for his friends. This stark contrast underscores the fear of the outside world and the desperate attempts to ignore the reality of the plague.

The welded locks of the abbey symbolize the fear of the outside world and the attempt to shut out death. Prospero and his guests isolate themselves, believing they can avoid the plague by sealing themselves away. The iron gates and welded bolts represent their fear and denial, as they try to keep the Red Death at bay. However, this isolation is ultimately futile, as the fear of death cannot be contained by physical barriers.

The ebony clock serves as a constant reminder of mortality, symbolizing the fear of death. Its chime interrupts the revelry, causing the dancers to pause in silence, acknowledging the passage of time and the approach of their inevitable end. The clock's presence in the black-draped room, where few dare to dance, emphasizes the ever-present fear of death that looms over the festivities.

When the personification of the Red Death appears at the masquerade, the guests react with terror and paralysis. The spectral figure, representing the inevitability of death, moves through the chambers unchallenged, as the courtiers are too frightened to confront it. This fear culminates in the death of Prince Prospero, who, despite his wealth and power, cannot escape his fate. The guests' realization that the figure is incorporeal underscores the theme that death is inescapable, regardless of attempts to avoid it.