In the Mendoza apartment all was a babel of voices, every one talking at once.

“Did you get them?” Craig asked, looking about.

“No, sir, replied the elevator boy.  “One of them came in from the ambulance and told me Miss Mendoza was suddenly taken sick.  He rode up with the stretcher.  The other one must have walked up.”

“Do you know him?  Has he ever been here before?”

“I can’t say, sir.  I didn’t see him.  At least, sir, when I heard the screams I ran in from the elevator, which the other one told me to wait with—­left the door open.  Just as I ran in, they dodged out past me, jumped into the car and rode down.  I guess they must have had the engine of the ambulance motor running, sir, if they got away without you seeing them.”

We were too late to head them from speeding off.  But, at least, we had saved the Senorita.  She was terribly upset by the attack, much shaken, but really all right.

“Have you any idea who it could be?” asked Craig as the faithful Juanita cared for her.

“I don’t know the man who was waiting and ’Nita never saw him, either,” she replied.  “The one who jumped out from behind the portieres had on a mask and a false beard.  But I didn’t recognize anything about him.”

Sudden as the attack had been and serious as might have been the outcome, we could not but feel happy that it had been frustrated.

Yet it seemed that some one ought to be delegated to see that such a thing could not occur again.

“We must think up some means of protecting you,” soothed Kennedy.  “Let me see, Mr. Lockwood and Mr. Whitney seem to be the closest to you.  If you don’t mind I’ll call them up.  I wonder if you’d object if we had a little luncheon up here, to-morrow?  I have a special reason for asking it.  I want to insure your safety and we may as well meet on common ground.”

“There isn’t the slightest objection in the world,” she replied, as Kennedy reached for the telephone.

We had some little difficulty in locating both Lockwood and Whitney, but finally after a time managed to find them and arrange for the conference on the Senorita’s safety for the next day.

Outside Kennedy gave instructions to the officer on the beat to watch the apartment particularly, and there was no reason now to fear a repetition of the attempt, at least that night.

XVIII

THE ANTIDOTE

Early the following morning Kennedy left me alone in the laboratory and made a trip downtown, where he visited a South American tobacco dealer and placed a rush order for a couple of hundred cigarettes exactly similar in shape and quality to those which Mendoza had smoked and which the others seemed also to prefer, except, however, that the deadly drug was left out.

While he was gone, it occurred to me to take up again the hunt for Alfonso.  Norton was not in his little office, nor could I find Alfonso anywhere about the campus.  In fact he seemed to have almost dropped out of his University work for the time.  Accordingly, I turned my steps toward the Prince Edward Albert Hotel, in the hope that he might be there.