What angers the prince?
In 'The Mask Of The Red Death,' we read that the country is in the grip of a 'pestilence' so fatal that it causes 'sharp pains, and sudden dizziness, and then profuse bleeding at the pores, with dissolution.' We are told that Prince Prospero is 'happy and dauntless and sagacious.' His solution to such a dire national catastrophe is to call up a thousand of his courtiers to retire with him 'to the deep seclusion of one of his castellated abbeys.' He arrogantly and selfishly declares that they will 'bid defiance to contagion' within the abbey while the 'external world could take care of itself.'
While there, he holds a masque in an imperial suite made up of seven rooms. The colors of the first six rooms are purple, green, orange, white, violet, and blue. The last room, however, is fully decorated with black, velvet tapestries which hang over the ceiling and down the walls; the corresponding black carpets give the room a sinister ambiance. The windows in this room are tinted blood-red. Few dare to go into this room. There is also an ebony clock in this room which chimes every hour, making all the revelers nervous enough to stop whatever they are doing when they hear it. At midnight, there suddenly appears a sinister figure, shrouded in the 'habiliments of the grave' and wearing a mask bearing the image of a stiffened corpse. Even though Prince Prospero demands that his courtiers seize the intruder, none dare to do so. Enraged by his momentary cowardice and angry that all of his courtiers are too afraid to obey his orders, he decides to kill the intruder himself. However, before he can carry out his kingly execution, he falls ' prostrate in death.'
Thanks for the question.