b of rock tilted to one side, as if on a pivot, revealing a
square opening which seemed to lead through solid stone. And at the far
end of the opening Tom Swift saw a glimmer of light.

Stooping down, he looked through the hole thus strangely opened and
what he saw caused him to cry out in wonder.

"It's the tunnel!" he cried. "I can look right down into the tunnel.
It's the incandescent lights I see. I can look right at the ledge of
rock where I kept watch that day, and where I saw--where I saw the face
of Waddington!" he cried. "It wasn't a dream after all. This is a
shaft connecting with the tunnel. We didn't discover it because this
rock fits right in the opening in the roof. It must have been there all
the while, and some blast brought it to light. Is this how the men got
out, or were taken out of the tunnel, Masni?" Tom asked.

"This how," said the Indian woman. "See, here rope!"

She pawed aside a mound of earth, and disclosed a rope buried there, a
rope knotted at intervals. This, let down through the hole in the roof
of the tunnel, provided a means of escape, and in such a manner that
the disappearance of the men was most mysterious.

"I see how it is!" cried Tom. "Some one interested, Waddington
probably, who knew about this old secret shaft going down into the
earth, used it as soon as our blasting was opened that far. They got
the men out this way, and hid them in the secret valley."

"But what for?" cried Mr. Damon.

"To cripple us! To cause the strike by making our other workers afraid
of some evil spirit! The men were taken away secretly, and, doubtless,
have been kept in idleness ever since--paid to stay away so the mystery
would be all the deeper. Our rivals finding they couldn't stop us in
any other way have taken our laborers away from us."

"Bless my meal ticket! It does look like that!" cried Mr. Damon.

"Of course that's the secret!" cried Tom. "Blakeson & Grinder, or some
of their tools--probably the bearded man or Waddington--found out about
this shaft which led down into our tunnel. They induced the first ten
men to quit, and when Tim went to get the fuse the rope was let down,
and the men climbed up here, one after the other. Those Indians can
climb like cats. Once the ten were out the shaft was closed with the
rock, and the ten men taken off to the valley to be secreted there.

"The same was done with the next fifteen, and, I suppose, if the strike
hadn't come, more of our workers w