turned and pressed a finger on a carved rosette in the oak panel.
Without a sound it slid open, and they found themselves in a narrow,
stone passage. Once more the strange girl motioned for silence. Then
she slid an iron grating across the secret door through which they had
come, and turning ran lightly down the passage. Without a moment's
hesitation, Evelyn started after, her hand still clasping the revolver
which she had taken from the table. The Professor, clutching his
recovered manuscript, followed, while Jack brought up the rear.

As they turned a corner, a faint shout reached them. The officers had
returned to the empty room!

The way was long, with many sharp turns. It seemed to be a space
between rooms. Once or twice shouts and laughter were faintly heard,
as they seemed to pass near a room full of soldiers. It was dark. The
girl ahead felt in her pocket, and brought out a tiny flashlight. They
came finally to a steep flight of stairs.

Now for the first time the girl spoke. In a cautious whisper she said,
"Be careful!" and holding the flash behind her for their guidance, went
swiftly and lightly down, with the manner of one who is familiar with
every inch of the way. The stairs were wide and shallow. There were a
great many of them and they seemed to go down a long way. Evelyn
wondered if the place was built on a hillside, making it a long way to
the underground regions she suspected beyond or below. She afterwards
found out that this was correct. A door barred with iron was at the
foot of the stairs. Indeed, they ended right against it. The girl
pushed the door open, and when they had entered, closed it behind them
and dropped a massive bar across it. They were in a large, stone
chamber, empty save for a few scraps of furniture.