“If it were a slow-smoldering—­”

“Shirley’s anger wasn’t that kind.”

“But good heavens!” As usual I arrived nowhere in an argument with Kennedy.  “Circumstantial evidence points to Werner almost altogether—­”

“You’ve forgotten one point in your chain, Walter.”

“What’s that?”

“Whoever took the needle from the curtain last night scratched himself on it and left blood spots on the portieres, tiny ones, but real blood spots, nevertheless.  That means the intruder inoculated himself with venom.  I doubt that the poison was so dry as to be ineffectual.  If it was Werner, how do you account for the fact that he is still alive?”

“Do you”—­I guess my eyes went wide—­“do you expect to dig up a dead man somewhere?  Is there some one we suspect and haven’t seen since yesterday?”

He didn’t answer, preferring to tantalize me.

“How do you account for it yourself?” I demanded, somewhat hotly.

“Let’s call it a day, Walter,” he rejoined.  “Let’s go to bed!”

 XVIII

THE ANTIVENIN

I slept late in the morning, so that Kennedy had to wake me.  When we had finished breakfast he led the way to the laboratory, all without making any effort to satisfy my curiosity.  There he started packing up the tubes and materials he had been studying in the case, rather than resuming his investigations.

“What’s the idea?” I asked, finally, unable to contain myself any longer.

“You carry this package,” he directed.  “I’ll take the other.”

I obeyed, somewhat sulkily I’m afraid.

“You see,” he added, as we left the building and hurried to the taxi stand near the campus, “the next problem is to identify the particular kind of venom that was used.  Besides, I want to know the nature of the spots on the towel you found.  They certainly were not of venom.  I have my suspicions what they really are.”

He paused while we selected a vehicle and made ourselves comfortable.  “To save time,” he went on, “I thought I’d just go over to the Castleton Institute.  You know in their laboratories the famous Japanese investigator, Doctor Nagoya, has made some marvelous discoveries concerning the venom of snakes.  It is his specialty, a matter to which he has practically devoted his life.  Therefore I expect that he will be able to confirm certain suspicions of mine very quickly, or”—­a shrug—­“explode a theory which has slowly been taking form in the back of my head.”

When we dismissed the taxi in front of the institute I realized that this would be my first visit to this institution so lavishly endowed by the multi-millionaire, Castleton, for the advancement of experimental science.  Kennedy’s card, sent in to Doctor Nagoya, brought that eminent investigator out personally to see us.  He was the very finest type of Oriental savant, a member of the intellectual nobility of the strange Eastern