Kennedy examined the hypodermic.

“Not like the one used,” he murmured.

“I thought that,” I explained.  “It simply indicates he is a dope fiend and is familiar with the use of a needle.  Here!” I produced the ink filler which I had used to bring a sample of the contents of the bottle.  “This seems to be what he uses.  What is it?”

Kennedy sniffed, then looked closely at the liquid through the glass of the tube.  “It’s a coca preparation,” he explained.  “If Werner uses this, he’s unquestionably a regular drug addict.”

“Well,” I paused, triumphantly, “the case against the chief director of Manton Pictures grows stronger all the time.”

“Not necessarily,” contradicted Kennedy, perhaps to draw me out.

“He’s familiar with hypodermic syringes,” I repeated.

“Which doesn’t prove that no one else would use one.”

“Anyhow, he was out until four A.M. last night and some one broke into Phelps’s house to—­”

“You can’t establish the fact that he went out there.  There are plenty of other places he could have been until four in the morning.”

“But I can assume—­”

“If you are going to assume anything, Walter, why not assume he was the second man, the man who watched the actual intruder?”

I turned away, despairing of my ability to convince Kennedy.  As a matter of fact I had forgotten the other prowler at Tarrytown.

Then I noticed that the one guinea pig in the separate cage was dead.  In an instant I was all curiosity to know the results of Kennedy’s investigations.

“Did you make any progress?” I asked.

“Yes!” Now I noticed for the first time that he was in fine humor.  “I had quite finished the first stage of my analysis when you came in.”

“Then what was it?  What was the poison that killed Stella Lamar?” I glanced at the stiff, prone figure of the little animal.

Kennedy cleared his throat.  “Well,” he replied, “I began the study with the discovery I made, which I told you, that strange proteins were present.”  He picked up the ampulla and regarded it thoughtfully.  Then he fingered the bit of silk cut from the portieres.  “It is a poison more deadly, more subtle, than any ever concocted by man, Walter.”

“Yes?” I was painfully eager.

“It is snake venom!”

XVI

ENID ASSISTS

“A poison more subtle than any concocted by man!” repeated Kennedy.

It was a startling declaration and left me quite speechless for the moment.

“We know next to nothing of the composition of the protein bodies in the snake venoms which have such terrific and quick physiological effects on man,” Kennedy went on.  “They have been studied, it is true, and studied a great deal, but we cannot say that there are any adequate tests by which the presence of these proteins can be recognized.