captivity.

In this way, they gradually arrived beneath the huge cellars below the
stage. They must at this time have been at the very bottom of the
"tub" and at an extremely great depth, when we remember that the earth
was dug out at fifty feet below the water that lay under the whole of
that part of Paris.[4]

The Persian touched a partition-wall and said:

"If I am not mistaken, this is a wall that might easily belong to the
house on the lake."

He was striking a partition-wall of the "tub," and perhaps it would be
as well for the reader to know how the bottom and the partition-walls
of the tub were built. In order to prevent the water surrounding the
building-operations from remaining in immediate contact with the walls
supporting the whole of the theatrical machinery, the architect was
obliged to build a double case in every direction. The work of
constructing this double case took a whole year. It was the wall of
the first inner case that the Persian struck when speaking to Raoul of
the house on the lake. To any one understanding the architecture of
the edifice, the Persian's action would seem to indicate that Erik's
mysterious house had been built in the double case, formed of a thick
wall constructed as an embankment or dam, then of a brick wall, a
tremendous layer of cement and another wall several yards in thickness.

At the Persian's words, Raoul flung himself against the wall and
listened eagerly. But he heard nothing ... nothing ... except distant
steps sounding on the floor of the upper portions of the theater.

The Persian darkened his lantern again.

"Look out!" he said. "Keep your hand up! And silence! For we shall
try another way of getting in."

And he led him to the little staircase by which they had come down
lately.

They went up, stopping at each step, peering into the darkness and the
silence, till they came to the third cellar. Here the Persian motioned
to Raoul to go on his knees; and, in this way, crawling on both knees
and one hand--for the other hand was held in the position
indicated--they reached the end wall.

Against this wall stood a large discarded scene from the ROI DE LAHORE.
Close to this scene was a set piece. Between the scene and the set
piece there was just room for a body ... for a body which one day was
found hanging there. The body of Joseph Buquet.

The Persian, still kneeling, stopped and listened. For a moment, he
seemed to hesitate and looked a