was a small knot hole, about an inch and a half in
diameter. Through this opening the light now shone distinctly, and it
was most welcome to the eyes of our young detective. A pressure was now
brought to bear upon the door from the under side, but it only yielded
so far as the fastening would allow.

"Is that you, Vermont?" whispered Bob through the knot hole.

No answer was given.

Herbert Randolph had never considered himself in any degree
superstitious. But what could this be but Bob Hunter's spirit?

"Don't be afraid," said the young detective, who imagined Herbert would
find it difficult to realize that he was there. "It's Bob Hunter. I
ain't got no card with me, or I'd send it down to you."

This remark sounded so much like Bob that young Randolph no longer
doubted his own senses.

"Bob Hunter!" exclaimed he. "How in the world came you here, and what
are you doing?"

"Yes, it's me, Vermont. But don't stop to ask no questions now. I'm here
to help you get out, but this blamed old door is locked, and I hain't
got no key, nor no light, nor nothin'."

After exchanging a few words, Herbert took from his pocket a piece of
paper. This he made into a taper, which he lighted and passed up through
the knot hole to Bob. With this the latter lighted the gas; and now he
felt that he was in a position to be of some service to his friend.

A careful search failed to reveal any keys. Then the two boys discussed
the situation, and presently Herbert passed a bent nail to the young
detective, and instructed him how to operate on the lock, which speedily
yielded to the boy's efforts. In another instant the trap door was
thrown up, and, by a most unfortunate blunder, it fell back with a
tremendous crash.

Herbert, however, emerged quickly from his cold, damp prison, with a
look of consternation pictured upon his face. Both he and Bob knew that
old Gunwagner would be upon them in less than a minute, and they hastily
prepared to defend themselves.

CHAPTER XVI.

THE OLD FENCE IN A TRAP.

"What shall we do?" said Bob, with no little alarm, as Herbert Randolph
climbed up through the old trap door.

"We must defend ourselves," replied the young Vermonter, with
characteristic firmness.

"There ain't no way to escape, is there?"

"No, I suppose not, if the hall door is locked."

"It is, and I can't find no key."

"Have you looked since the gas was lighted?"

"Yes, and 'tain't there nowhere."

"Where do you