the middle of the night and wandering off into the mine!"

"What did you do?" demanded Tommy.

"We waited until morning, and then enlisted the services of the
caretaker," replied Will. "So far as I can remember, this is about
the nine hundredth relief expedition we've been out on in search of
you boys!"

"Seems to me," Tommy chuckled, "that you're the lads that were in need
of the relief expedition. We found you boxed up in a chamber in a
boat."

"But we wouldn't have been in any such mess if we hadn't started out
to look you up!" George declared.

"We should have been back before you got out of bed this morning, if
some one hadn't cut our string," replied Sandy. "We had a cinch on
getting out, but some geezer led us a fool chase by cutting our cord
and steering us around in a circle."

"Did you see any one?" asked Will.

"Not a soul!" was the reply. "But there's some one in here, just the
same. We heard the call of the Wolf Patrol a long time ago and we've
heard it several times since."

"What do you mean by some one cutting your string?" asked George.

"Why," replied Sandy, "we tied the loose end of a ball of twine to one