from the back cover:
It is 1880, in the Opera House in Paris. Everybody is talking about the Phantom of the Opera, the ghost that lives somewhere under the Opera House. The Phantom is a man in black clothes. He is a body without a head, he is a head without a body. He has a yellow face, he has no nose, he has black holes for eyes. Everybody is afraid of the Phantom - the singers, the dancers, the directors, the stage workers . . .

But who has actually seen him?