ent it, and to
whom, is all a mystery."

"But could you make out enough of the message, Hugh, to give you any
idea what it stood for?" persisted Thad.

"Yes, I believe I did," the other admitted, solemnly, so that each of
his chums bent closer to catch the next words that fell from his
lips. "I'm certain it spelled out the word 'help,' for one; and I
thought another was 'quick'!"

"Oh! what do you think of that?" gasped Horatio.

"The mystery deepens," added Owen, dramatically, just as he had
probably been accustomed to reading in some story of excitement.

"Of course," continued Hugh, immediately, "we've got to take a look
around that same old quarry, and see what's going on. Somebody's
holding the fort there, even if it is said to be deserted. Who and
what he can be, of course, remains to be seen; but I'm not taking a
bit of stock in those old wives' yarns about a ghost, remember,
Horatio."

"Then we'll have to leave the car on the road, won't we, Hugh, when
we tackle this big job?" questioned Owen.

"Of course; and since I marked the best spot where anyone could make
their way along to the face of the quarry, we must start up again,
and keep moving till we strike that place."

"But, Hugh, do you think the--er--party making those signals with a
light could have noticed our illumination, and that message was meant
for us?" Horatio went on to ask, solicitously.

"I'm not prepared to say," he was told, "though I don't see how
anybody with eyes could miss discovering us coming along. And,
besides, the old car makes plenty of noise in the bargain, to attract
attention. So it looks as if he did know, and was trying to talk to
us."

All this only added to the thrill that was forever passing through
each and every member of the night expedition. It would be
manifestly impossible to describe their mixed feelings as they
advanced slowly along the rough road so long abandoned to nature. A
dozen times Horatio believed he heard cries; why, it seemed as though
the air must be filled with uncanny sounds, for his lively
imagination was working at race-horse speed just then.

The car stopped short.

"Wow! what's happened now, Hugh?" whispered Horatio.

"We've arrived at the getting-out place, that's all," came the steady
reply, as the chauffeur caused the engine to cease working and then
proceeded to leave his seat, after his companion had jumped out.

The lanterns were now lighted and the electric torch made