furnace room, and were looking down a short flight of steps, into
a sort of vault, evidently under the pavement. A faint light came
from a small grating above, and there was a close, musty smell in
the air.

"I tell you it must have been last night," Dallas was saying.
"Wilson and I were here before we went to bed, and I'll swear
that hole was not there then."

"It was not there this morning, sir," Flannigan insisted. "It has
been made during the day."

"And it could not have been done this afternoon," Mr. Harbison
said quietly. "I was fussing with the telephone wire down here. I
would have heard the noise."

Something in his voice made me look at him, and certainly his
expression was unusual. He was watching us all intently while
Dallas pointed out to me the cause of the excitement. From the
main floor of the furnace room, a flight of stone steps
surmounted by an arch led into the coal cellar, beneath the
street. The coal cellar was of brick, with a cement floor, and in
the left wall there gaped an opening about three feet by three,
leading into a cavernous void, perfectly black--evidently a
similar vault belonging to the next house.

The whole place was ghostly, full of shadows, shivery with
possibilities. It was Mr. Harbison finally who took Jim's candle
and crawled through the aperture. We waited in dead silence,
listening to his feet crunching over the coal beyond, watching