“Mr. Mackay here”—­Kennedy smiled, very slightly—­“is the district attorney with jurisdiction at Tarrytown.  At my request, since yesterday—­or, to be exact, since the death of Mr. Werner warned us that no time could be lost—­he has carried a ‘John Doe’ warrant.  Immediately following my identification of the guilty person he—­or she—­will be placed under arrest.  The charge will be the murder of Stella Lamar by the use of poison in a manner which I will explain to you.  The trial will take place at White Plains, the county seat of Westchester County, where the murder occurred.  Mr. Mackay informs me that the courts there are not crowded; in fact, he personally has been able to devote most of his time to this case.  Therefore the trial will be speedy and I am sure that the cold-blooded methods used by this criminal will guarantee a quick sentence and an early trip to the electric chair at Ossining.  Now”—­suddenly grim—­“if everyone will go down to the projection room, the larger one, we will bring matters to their proper conclusion.”

I imagined that Kennedy’s speech was calculated to spread a little wholesome fear among the people we had considered suspects.  In any case that was the result, for an outsider, from the expressions upon the various faces, might have concluded that several of them were guilty.  Each seemed to start off across the studio floor reluctantly, as though afraid to obey Kennedy, yet unable to resist the fascination of witnessing the identification of the criminal, as though feeling that he or she individually might be accused, and yet unwilling to seek safety at the expense of missing Kennedy’s revelation of his methods and explanation of their result.

I drew him aside as quickly as I could.

“Craig,” I started, eagerly, “isn’t this all unnecessary?  Can’t you see that Shirley is the guilty man?  If you will hurry into his room with paper and pencil and get his confession before he recovers from his fright and regains his assurance—­”

“What on earth, Walter!” Kennedy interrupted me with a look of surprise which I did not miss even in my excitement.  “What are you driving at, anyway?”

“Why, Shirley is the criminal.  He—­”

“Nonsense!  Wasn’t an attempt made to kill him just now?  Wasn’t it evident that he was considered as dangerous to the unknown as Werner, the director?  Hasn’t he been eliminated from our calculations as surely as the man slain yesterday?” “No!” I flushed.  “Not at all, Craig!  This was not an attempt at murder.  There were none of the criminal’s earmarks noticeable at Tarrytown or in the banquet scene.”

“How do you mean, Walter?” For once Kennedy regarded me seriously.

“Why, you pointed out yourself that this unknown was exceptionally clever.  The attempt on Shirley, if it were an attempt, was not clever at all.”

“Why?”

“Why?” I was a little sarcastic, because I was sure of myself.  “Because the poison was atropin—­belladonna.  That is common.  I’ve read of any number of crimes where that was used.  Do you think for a moment that the mind which figured out how to use snake venom, and botulin toxin, would descend to anything as ordinary as all this?”