nights before. "Won't you
answer one other question?"

Fainter, almost imperceptibly, came a rap! rap!

For several minutes the old man sat absorbed in thought, trance-like.
Then, gradually, he seemed to realise that we were in the room with
him. With difficulty he took up the thread of the conversation where the
rappings had broken it.

"We were talking about the photographs," he said slowly. "I hope soon
to get one of my wife as she is now that she is transfigured. John has
promised me one soon."

He was gathering up his treasures preparatory to putting them back in
their places of safekeeping. The moment he was out of the room Craig
darted into the cabinet and replaced his mechanism in the box. Then he
began softly to tap the walls. At last he found the side that gave a
noise similar to that which we had heard, and he seemed pleased to have
found it, for he hastily sketched on an old envelope a plan of that part
of the house, noting on it the location of the side of the cabinet.

Kennedy almost dragged me back to our apartment, he was in such a hurry
to examine the apparatus at his leisure. He turned on all the lights,
took the thing out of its case, and stripped off the two sheets of ruled
paper wound around the two revolving drums. He laid them flat on
the table and studied them for some minutes with evidently growing
satisfaction.

At last he turned to me and said, "Walter, here is a ghost caught in the
act."

I looked dubiously at the irregular up-and-down scrawl on the paper,
while he rang up the Homicide Bureau of the Central Office and left word
for O'Connor to call him up the first thing in the morning.

Still eyeing with satisfaction the record traced on the sheets of paper,
he lighted a cigarette in a matter-of-fact way and added: "It proves to
be a very much flesh-and-blood ghost, this 'John.' It walked up to the
wall back of that cabinet, rapped, listened to old Vandam, rapped
some more, got the answer it wanted, and walked deliberately away. The
cabinet, as you may have noticed, is in a corner of the room with one
side along the hallway. The ghost must have been in the hall."

"But who was it?"

"Not so fast, Walter," laughed Craig. "Isn't it enough for one night
that we have found out that much?"

Fortunately I was tired, or I certainly should have dreamed of rappings
and of "John" that night. I was awakened early by Kennedy talking with
someone over the telephone. It was Inspector O'Conn