What did it mean?  I recalled that Doctor Scott had particularly said that Barrios had not been wounded.

Still regarding the cartridge shell, Kennedy sat down at the desk of Barrios.

Looking for a piece of paper in which to wrap the shell, he pulled out the middle drawer of the desk.  In a back corner was a package of letters, neatly tied.  We glanced at them.  The envelopes bore the name of Jose Barrios and were in the handwriting of a woman.  Some were postmarked Cuba; others, later, New York.  Kennedy opened one of them.

I could not restrain an exclamation of astonishment.  I had expected that they were from Eulalie Sandoval.  But they were signed by a name that we had not heard—­Teresa de Leon!

Hastily Kennedy read through the open letter.  Its tone seemed to be that of a threat.  One sentence I recall was, “I would follow you anywhere—­I’ll make you want me.”

One after another Kennedy ran through them.  All were vague and veiled, as though the writer wished by some circumlocution to convey an idea that would not be apparent to some third, inquisitive party.

What was back of it all?  Had Jose been making love to another woman at the same time that he was engaged to Eulalie Sandoval?  As far as the contents of the letters went there was nothing to show that he had done anything wrong.  The mystery of the “other woman” only served to deepen the mystery of what little we already knew.

Craig dropped the letters into his pocket along with the shell, and walked around into the office of Sandoval.  I followed him.  Quickly he made a search, but it did not seem to net him anything.

Meanwhile I had been regarding a queer-looking instrument that stood on a flat table against one wall.  It seemed to consist of a standard on each end of which was fastened a disk, besides several other arrangements the purpose of which I had not the slightest idea.  Between the two ends rested a glass tube of some liquid.  At one end was a lamp; the other was fitted with an eyepiece like a telescope.  Beside the instrument on the table lay some more glass-capped tubes and strewn about were samples of raw sugar.

“It is a saccharimeter,” explained Kennedy, also looking at it, “an instrument used to detect the amount of sugar held in solution, a form of the polariscope.  We won’t go into the science of it now.  It’s rather abstruse.”

He was about to turn back into the outer office when an idea seemed to occur to him.  He took the cartridge from his pocket and carefully scraped off what he could of the powder that still adhered to the outer rim.  It was just a bit, but he dissolved it in some liquid from a bottle on the table, filled one of the clean glass tubes, capped the open end, and placed this tube in the saccharimeter where the first one I noticed had been.

Carefully he lighted the lamp, then squinted through the eyepiece at the tube of liquid containing what he had derived from the cartridge.  He made some adjustments, and as he did so his face indicated that at last he began to see something dimly.  The saccharimeter had opened the first rift in the haze that surrounded the case.