Final answer:
In "The Masque of the Red Death," the revelers' first reaction to the masked intruder is fear and panic.
Step-by-step explanation:
In "The Masque of the Red Death," when the revelers finally notice the masked intruder, their first reaction is fear and panic. The masked intruder is described as having a figure resembling a corpse and wearing a death-like mask, which instills a sense of terror in the revelers.
The intruder is described as having the visage of a stiffened corpse, dressed in grave clothes, and with the features of the Red Death itself, suggesting the ultimate futility of trying to escape the plague.
The presence of the figure casts a shadow over the previously light-hearted revelry, leading to tension and fearful curiosity among the guests.