I calculated that we were in a narrow circular gallery, probably running all round the Opera, which is immense, underground.

I had once been down into those cellars, but had stopped at the third floor, though there were two lower still, large enough to hold a town.

But the figures of which I caught sight had made me run away.

There are demons down there, quite black, standing in front of boilers, and they wield shovels and pitchforks and poke up fires and stir up flames and, if you come too near them, they frighten you by suddenly opening the red mouths of their furnaces ...

Well, while Cesar was quietly carrying me on his back, I saw those black demons in the distance, looking quite small, in front of the red fires of their furnaces: they came into sight, disappeared and came into sight again, as we went on our winding way.