't you?" asked the boy of the caretaker.

"There is such a place," replied the caretaker.

"Can you find it?"

"Of course I can."

"Does the fall open into the system of chambers in the center or to the
north? You understand what I mean! Is it possible to enter any of the
benches or chambers connecting with the north gangway on the lower level
by means of this deserted shaft?"

"I am not quite certain about that," replied Canfield, "but my idea is
that the north benches and chambers can be reached by means of that
opening. I am glad you thought of that," he went on.

Dick now returned with the rope, and the three proceeded down the second
level until they came to a confusion of passages and benches which would
certainly have bewildered any one not familiar with the mine.

"Unless I am very much mistaken," Canfield went on, "this passage, the
one straight ahead, runs almost directly over Tunnel Six. If I am right
in this, the deserted shaft is here."

"And Tunnel Six is the haunted corridor, isn't it?" asked Dick.

"That's where the lights have been seen!" replied the caretaker.

"You never believed in the ghost stories told about Tunnel Six?" asked
Will. "I should think you'd begin to see now that the alleged ghosts
were pretty material things."

"Well, I don't know about the ghosts," replied the caretaker, "but I
really was getting a little bit nervous when you boys arrived. You
know," he continued, "that we all feel a little shivery when we butt
into anything which we can't understand."

"Well, suppose you follow this passage to the end and see if you
discover anything like the deserted shaft," suggested Dick.

"You're not going to venture into the lower level again, are you?" asked
Canfield. "I don't blame you boys for wanting to rescue your companions,
but, at the same time, I don't want to see you throw your lives away.
Those are desperate men in Tunnel Six!"

"If my idea is worth anything at all," replied Will, "we'll get the boys
out without ever letting the hold-up men know that we are within a mile
of them. You know we had very little difficulty in getting out of the
chamber where we left the boat."

"Trust you boys for inventing ways of doing things!" exclaimed Canfield.

"Of course," Will said hesitatingly after a time, "it may be that this
deserted shaft doesn't connect with Tunnel Six, but even if it doesn't,
we'll find some way of getting to our friends from the new position. We
can only