Kennedy did not reply.  He was apparently wrapped up in the consideration of the remarkable events of the evening.

As for myself, it was a state of affairs which, the day before, I should have pronounced utterly beyond the wildest bounds of the imagination of the most colorful writer.  Yet here it was; I had seen it.

I glanced up to find Kennedy standing by the light examining something he had apparently picked up at the Red Lodge.  I bent over to look at it, too.  It was a little glass tube.

“An ampoule, I believe the technical name of such a container is,” he remarked, holding it closer to the light.

In it were the remains of a dried yellow substance, broken up minutely, resembling crystals.

“Who dropped it?” I asked.

“Vaughn, I think,” he replied.  “At least, I saw him near Blair, stooping over him, at the end, and I imagine this is what I saw gleaming for an instant in the light.”

Kennedy said nothing more, and for my part I was thoroughly at sea and could make nothing out of it all.

“What object can such a man as Dr. Vaughn possibly have in frequenting such a place?” I asked at length, adding, “And there’s that Mrs. Langhorne—­she was interesting, too.”

Kennedy made no direct reply.  “I shall have them shadowed to-morrow,” he said briefly, “while I am at work in the laboratory over this ampoule.”

As usual, also, Craig had begun on his scientific studies long before I was able to shake myself loose from the nightmares that haunted me after our weird experience of the evening.

He had already given the order to an agency for the shadowing, and his next move was to start me out, also, looking into the history of those concerned in the case.  As far as I was able to determine, Dr. Vaughn had an excellent reputation, and I could find no reason whatever for his connection with anything of the nature of the Red Lodge.  The Rapports seemed to be nearly unknown in New York, although it was reported that they had come from Paris lately.  Mrs. Langhorne was a divorcee from one of the western states, but little was known about her, except that she always seemed to be well supplied with money.  It seemed to be well known in the circle in which Seward Blair moved that he was friendly with her, and I had about reached the conclusion that she was unscrupulously making use of his friendship, perhaps was not above such a thing as blackmail.

Thus the day passed, and we heard no word from Veda Blair, although that was explained by the shadows, whose trails crossed in a most unexpected manner.  Their reports showed that there was a meeting at the Red Lodge during the late afternoon, at which all had been present except Dr. Vaughn.  We learned also from them the exact location of the Lodge, in an old house just across the line in Westchester.

It was evidently a long and troublesome analysis that Craig was engaged in at the laboratory, for it was some hours after dinner that night when he came into the apartment, and even then he said nothing, but buried himself in some of the technical works with which his library was stocked.  He said little, but I gathered that he was in great doubt about something, perhaps, as much as anything, about how to proceed with so peculiar a case.