| Quote #10
When the eyes of Prince Prospero fell upon this spectral image (which with a slow and solemn movement, as if more fully to sustain its role, stalked to and fro among the waltzers) he was seen to be convulsed, in the first moment with a strong shudder either of terror or distaste; but, in the next, his brow reddened with rage. (10)
When the Red Death arrives on the scene, something changes. The Red Death feels no more real than anything else at the ball. It's called a "spectral image," meaning it looks somehow non-material or "otherworldly," like a ghost. To that extent, it fits into the dream world. It's even described as "playing a role," like an actor – lending another sense of unreality to the whole situation. But Prospero is no longer in control of the dream world. He's shocked, disgusted, and outraged and outraged to see the Red Death. But it is not in his power.