It was late that night when a gentle tap at the door proved that Kennedy’s hope had not been unfounded. I opened it and let in Edward, the valet, who produced the fragments of a note, torn and crumpled.

“There is nothing new, sir,” he explained, “except that Mrs. Pitts seems more nervous than ever, and Mr. Pitts, I think, is feeling a little brighter.”

Kennedy said nothing, but was hard at work with puckered brows at piecing together the note which Edward had obtained after hunting through the house. It had been thrown into a fireplace in Mrs. Pitts’s own room, and only by chance had part of it been unconsumed. The body of the note was gone altogether, but the first part and the last part remained.

Apparently it had been written the very morning on which the murder was discovered.

It read simply, “I have succeeded in having Thornton declared …” Then there was a break. The last words were legible, and were, “… confined in a suitable institution where he can cause no future harm.”

There was no signature, as if the sender had perfectly understood that the receiver would understand.

“Not difficult to supply some of the context, at any rate,” mused Kennedy. “Whoever Thornton may be, some one has succeeded in having him declared ‘insane,’ I should supply. If he is in an institution near New York, we must be able to locate him. Edward, this is a very important clue. There is nothing else.”

Kennedy employed the remainder of the night in obtaining a list of all the institutions, both public and private, within a considerable radius of the city where the insane might be detained.

The next morning, after an hour or so spent in the laboratory apparently in confirming some control tests which Kennedy had laid out to make sure that he was not going wrong in the line of inquiry he was pursuing, we started off in a series of flying visits to the various sanitaria about the city in search of an inmate named Thornton.

I will not attempt to describe the many curious sights and experiences we saw and had. I could readily believe that any one who spent even as little time as we did might almost think that the very world was going rapidly insane. There were literally thousands of names in the lists which we examined patiently, going through them all, since Kennedy was not at all sure that Thornton might not be a first name, and we had no time to waste on taking any chances.