The story takes place during a plague where Prince Prospero calls his friends together to come to his castle to have fun until the plague has passed.
During the plague Prince Prospero has his friends come with him to his castle until the plague has ended. A masquerade is planned and in the usual Poesque style, the large halls are described in imagery that foreshadows the horror that follows. The ball night arrives and the guests arrive in their costumes and the festivities begin. The fun is stopped by the arrival of a guest who was dressed in the garments with the scarlet blood associated with the plague of "red death." The visitor walks the halls until is met up by the host in the black hall. Without explanation the host falls dead at the visitor's feet revelers, they find that the costume is "untenanted by any tangible form". The rest of the guests begin to die in their tracks as they acknowledge the presence of the Red Death.
The problem of the story was that there was a plague and they were trying to escape it by going to the Prince's castle.
The people at the masquerade end up dying from the red death.