“I think I know what we have here,” he said, briefly, rising and placing the tube and its contents in his pocket with the other things he had discovered.  “Of course it is only a hint.  This instrument won’t tell me finally.  But it is worth following up.”

With a final glance about to make sure that we had overlooked nothing, Kennedy closed and locked the outside door.

“I’m going directly up to the laboratory, Walter,” decided Kennedy.  “Meanwhile you can help me very much if you will look up this Teresa de Leon.  I noticed that the New York letters were written on the stationery of the Pan-America Hotel.  Get what you can.  I leave it to you.  And if you can find out anything about the others, so much the better.  I’ll see you as soon as you finish.”

It was rather a large contract.  If the story had reached the newspaper stage, I should have known how to go about it.  For there is no detective agency in the world like the Star, and even on the slender basis that we had, with a flock of reporters deployed at every point in the city, with telephones, wires, and cables busily engaged, I might have gathered priceless information in a few hours.  But, as it was, whatever was to be got must be got by me alone.

I found Teresa de Leon registered at the Pan-America, as Craig had surmised.  Such inquiries as I was able to make about the hotel did not show a trace of reason for believing that Jose Barrios had been numbered among her visitors.  While that proved nothing as to the relations of the two, it was at least reassuring as far as Anitra and Eulalie were concerned, and, after all, as in such cases, this was their story.

Not having been able to learn much about the lady, I decided finally to send up my card, and to my satisfaction she sent back word that she would receive me in the parlor of the hotel.

Teresa de Leon proved to be a really striking type of Latin-American beauty.  She was no longer young, but there was an elusiveness about her personality that made a more fascinating study than youth.  I felt that with such a woman directness might be more of a surprise than subtlety.

“I suppose you know that Senor Barrios is very seriously ill?” I ventured, in answer to her inquiring gaze that played from my card to my face.

For a fleeting instant she looked startled.  Yet she betrayed nothing as to whether it was fear or surprise.

“I have called his office several times,” she replied, “but no one answered.  Even Senor Sandoval was not there.”

I felt that she was countering as cleverly as I might lead.  “Then you know Mr. Sandoval also?” I asked, adding, “and Mr. Page?”

“I have known Senor Barrios a long time in Cuba,” she answered, “and the others, too—­here.”