Impatient as I was, I often wondered what must have been the suspense of those to whom the case meant everything.

“How are the tests coming along?” I ventured one night, after Kahn had arranged for the uncovering of the grave.

It was now two days since Kennedy had gone up to East Point to superintend the exhumation and had returned to the city with the materials which had caused him to keep later hours in the laboratory than I had ever known even the indefatigable Craig to spend on a stretch before.

He shook his head doubtfully.

“Walter,” he admitted, “I’m afraid I have reached the limit on the line of investigation I had planned at the start.”

I looked at him in dismay.  “What then?” I managed to gasp.

“I am going up to East Point again to-morrow to look over that house and start a new line.  You can go.”

No urging was needed, and the following day saw us again on the ground.  The house, as I have said, had been almost torn to pieces in the search for the will and the poison evidence.  As before, we went to it unannounced, and this time we had no difficulty in getting in.  Kennedy, who had brought with him a large package, made his way directly to a sort of drawing-room next to the large library, in the closet of which the will had been discovered.

He unwrapped the package and took from it a huge brace and bit, the bit a long, thin, murderous looking affair such as might have come from a burglar’s kit.  I regarded it much in that light.

“What’s the lay?” I asked, as he tapped over the walls to ascertain of just what they were composed.

Without a word he was now down on his knees, drilling a hole in the plaster and lath.  When he struck an obstruction he stopped, removed the bit, inserted another, and began again.

“Are you going to put in a detectaphone?” I asked again.

He shook his head.  “A detectaphone wouldn’t be of any use here,” he replied.  “No one is going to do any talking in that room.”

Again the brace and bit were at work.  At last the wall had been penetrated, and he quickly removed every trace from the other side that would have attracted attention to a little hole in an obscure corner of the flowered wall-paper.

Next, he drew out what looked like a long putty-blower, perhaps a foot long and three-eighths of an inch in diameter.

“What’s that?” I asked, as he rose after carefully inserting it.

“Look through it,” he replied simply, still at work on some other apparatus he had brought.

I looked.  In spite of the smallness of the opening at the other end, I was amazed to find that I could see nearly the whole room on the other side of the wall.

“It’s a detectascope,” he explained, “a tube with a fish-eye lens which I had an expert optician make for me.”

“A fish-eye lens?” I repeated.

“Yes.  The focus may be altered in range so that any one in the room may be seen and recognised and any action of his may be detected.  The original of this was devised by Gaillard Smith, the adapter of the detectaphone.  The instrument is something like the cytoscope, which the doctors use to look into the human interior.  Now, look through it again.  Do you see the closet?”