“Miss Loring told us that Shirley suspected some one and was watching, and would not tell her or anyone else who it was.  It seems most likely to me that it is the truth, Mackay.  In that case her remark means that she believes his silence in a way is responsible for Werner’s death.”

“Oh!  If Shirley had taken you into his confidence, for instance—?”

“I might possibly have succeeded in gaining sufficient evidence for an arrest, thus averting this tragedy.  But it is only a theory of mine.”

I scowled.  It seemed to me that Kennedy was minimizing things in a way unusual for him.  I wondered if he really thought the heavy man innocent.

“It’s still my belief that Shirley is guilty,” I asserted.

A sound of confusion from the courtyard beneath the heavy studio windows caught Kennedy’s ear and ended the colloquy.  From some of those near enough to look out we received the explanation.  The police had arrived, fully three-quarters of an hour after Werner’s death.

“I’ll get the little bottle of wine, sure,” Mackay murmured, picking up the food samples he had wrapped and crowding the bulky package into a pocket.

“I don’t see why that would have been any easier to poison than the food,” was my objection.  “Everyone was looking.”

“Very simple.  The food was brought in quite late.  Besides, it was dished out by the caterer before the eyes of forty or fifty people or more and there was no telling which plate would go to Werner’s place.  The drinks were poured last of all.  I remember seeing the bubbles rise and wondering whether they would register at the distance.”

Kennedy did not look at me.  “Did it ever occur to you,” he went on, casually, “that the glasses were all set out empty at the various places long before, and that there might easily have been a few drops of something, if it were colorless, placed in the bottom of Werner’s glass, with scarcely a chance of its being discovered, especially by a man who had so much on his mind at the time as Werner had?  He must have indicated where he would sit when he arranged the camera stands and the location of the tables.”

I had not thought of that.

Kennedy frowned.  “If only I could have located more of that broken glass!” As he faced me I could read his disappointment.  “Walter, I’ve made a most careful search of his chair and the table and everything about the space where he dropped.  The poison must have been in the wine, but there’s not a tiny sliver of that glass left, nothing but a thousand bits ground into the canvas, too small to hold even a drop of the liquid.  Just think, a dried stain of the wine, no matter how tiny, might have served me in a chemical analysis.”

Very suddenly there was a low exclamation from Mackay.  “Look!  Quick!  Some one must have kicked it way over here!”

Fully twenty feet from Werner’s place in the glare of the lights was the hollow stem of a champagne glass, its base intact save for a narrow segment.  In the stem still were a couple of drops of the wine, as if in a bulb or tube.