could find your way perfectly well through this dark labyrinth."

"Yes, indeed! I have the whole plan of the old pit still in my head."

Harry, followed by the engineer, and holding his lamp high
the better to light their way, walked along a high gallery,
like the nave of a cathedral. Their feet still struck against
the wooden sleepers which used to support the rails.

They had not gone more than fifty paces, when a huge stone
fell at the feet of James Starr. "Take care, Mr. Starr!"
cried Harry, seizing the engineer by the arm.

"A stone, Harry! Ah! these old vaultings are no longer quite secure,
of course, and--"

"Mr. Starr," said Harry Ford, "it seems to me that stone was thrown,
thrown as by the hand of man!"

"Thrown!" exclaimed James Starr. "What do you mean, lad?"

"Nothing, nothing, Mr. Starr," replied Harry evasively, his anxious
gaze endeavoring to pierce the darkness. "Let us go on.
Take my arm, sir, and don't be afraid of making a false step."

"Here I am, Harry." And they both advanced, whilst Harry looked
on every side, throwing the light of his lamp into all the corners
of the gallery.

"Shall we soon be there?" asked the engineer.