Underneath this inscription appeared the rude drawing of a dagger in which some effort had evidently been made to make it appear three-sided.

“Well, of all things, what do you think of that?” I cried, tossing the thing over to Kennedy.

He took it and read it; his face puckered deeply.  “I’m not surprised,” he said, a moment later, looking up.  “Do you know, I was just about to tell you what happened at the library.  I had a feeling all the time I was there of being watched.  I don’t know why or how, but, somehow, I felt that some one was interested in the books I was reading.  It made me uncomfortable.  I was late, anyhow, and I decided not to give them the satisfaction of seeing me any more—­at least in the library.  So I have had a number of the books on Peru which I wanted reserved, and they’ll be sent over later, here.  No, I’m not surprised that you received this.  Would you remember the boy?” he asked of Tommy.

“I think so,” replied Tommy.  “He didn’t have on a uniform, though.  It wasn’t a messenger.”

There was no use to question him further.  He had evidently told all that he knew, and finally we had to let him go, with a parting injunction to keep his eyes open and his mouth shut.

Kennedy continued to study the note on the quarter sheet of paper long after the boy had gone.

“You know,” he remarked thoughtfully, after a while, “as nearly as I can make the thing out with the slender information that we have so far, the weirdest superstitions seem to cluster about that dagger which Norton lost.  I wouldn’t be surprised if it took us far back into the dim past of the barbaric splendour of the lost Inca civilization of Peru.”

He waved the sheet of paper for emphasis.  “You see, some one has used it here as a sign of terror.  Perhaps somehow it bore the secret of the big fish—­who knows?  None of the writers and explorers have ever found it.  The most they can say is that it may be handed down from father to son through a long line.  At any rate, the secret of the hiding-place seems to have been safely kept.  No one has ever found the treasure.  It would be strange, wouldn’t it, if it remained for some twentieth-century civilized man to unearth the thing and start again the curse that historians say was uttered and seems always to have followed the thing?”

“Kennedy, this affair is getting on my nerves already.”

While Craig was speaking the door of the laboratory had opened without our hearing it, and there stood Norton again.  He had waited until Craig had finished before he had spoken.

We looked at him, startled, ourselves.

“I had some work to do after I left you,” went on Norton, without stopping.  “In my letter-box were several letters, but I forgot to look at them until just now, when I was leaving.  Then I picked them up—­and—­look at this thing that was among them.”

Norton laid down on the laboratory table a plain envelope and a quarter sheet of paper on which were printed, except for his own name instead of mine, an almost exact replica of the note which I had received.