scious of that feeling of being watched. Perhaps I
had heard a footstep outside and did not remember it, but at any rate I
had the feeling. I stopped tapping the keys suddenly and wheeled about
in my chair just in time to catch a glimpse of a face dodging back from
the window. I don't think that I would be prepared to swear just who it
was, but there was just enough that was familiar about the fleeting
glimpse of the eyes to make me feel uncomfortable.

I ran to the door, but it was too late. The intruder had disappeared.
Still, the more I thought about it, the more determined I was to verify
my suspicions, if possible. I put on my hat and walked over to the
registrar's office. Sure enough, Alfonso de Moche was registered in the
summer school as well as in the regular course. I was now fully
convinced that it was he who had been watching us.

Not satisfied, I determined to make further inquiries about the young
man. He had been at the University that morning, I learned from one of
his professors, and that convinced me more than ever that he had
employed at least a part of the time in spying on us. As I had expected,
the professor told me that he was an excellent student, though very
quiet and reserved. His mind seemed to run along the line of engineering
and mining, especially, and I could not help drawing the conclusion that
perhaps he, too, was infected by the furore for treasure hunting, in
spite of his Indian ancestry.

Nothing further occurred, however, during the day to excite suspicion
and Craig listened with interest, though without comment, when I related
what had happened. He divided his time during the rest of the day
between some experimental work of his own and fits of deep reverie in
which he was evidently trying to piece together the broken strands of
the strange story in which we were now concerned.

The package of cigarettes which he had ordered was delivered late in the
afternoon. Kennedy had already wrapped up a small package of a powder
and filled a small atomizer with some liquid. Stowing these things away
in his pockets as best he could, with a little vial which he shoved into
his waistcoat pocket, he announced that he was ready at last to take an
early train to Atlantic Beach.

We dined that night, as Craig had requested, with the Mendozas and
Lockwood up in the sitting-room of Don Luis's suite. It was a
delightfully situated room, overlooking the boardwalk and the ocean, and
the fresh wind t