Sampson shifted in his chair. “Listens like a thriller, Q,” he said admiringly. “But I’m not clear on a few points. For example, if this tetra ethyl lead is so little known, how on earth did Barry ever find out about it—to the degree of actually making some himself?” “Oh.” The Inspector smiled. “That worried me from the moment Jones described the poison. I was in the dark even after the capture. And yet—it just goes to show how stupid I am—the answer was under my nose all the time. You will remember that at the Ives-Pope place a certain Dr. Cornish was introduced. Now Cornish is a personal friend of the old financier and both of them are interested in medical science. In fact, I recall Ellery’s asking at one time: ‘Didn’t Ives-Pope recently donate $100,000 to the Chemical Research Foundation?’ That was true. It was on the occasion of a meeting in the Ives-Pope house one evening several months ago that Barry accidentally found out about tetra ethyl lead. A delegation of scientists had called upon the magnate, introduced by Cornish, to request his financial aid in the Foundation. In the course of the evening, the talk naturally turned to medical gossip and the latest scientific discoveries. Barry admitted that he overheard one of the directors of the Foundation, a famous toxicologist, relate to the group the story of the poison. At this time Barry had no idea that he would put the knowledge to use; when he decided to kill Field, he saw the advantages of the poison and its untraceable source immediately.” “What the deuce was the significance of that message you sent to me by Louis Panzer Thursday morning, Inspector?” inquired Cronin curiously. “Remember? Your note requested that I watch Lewin and Panzer when they met to see if they knew each other. As I reported to you, I asked Lewin later and he denied any acquaintance with Panzer. What was the idea?” “Panzer,” repeated the Inspector softly. “Panzer has always intrigued me, Tim. At the time I sent him to you, remember the hat deductions which absolved him had not yet been made.... I sent him to you merely out of a sense of curiosity. I thought that if Lewin recognized him, it might point to a connection between Panzer and Field. My thought was not borne out; it wasn’t too hopeful to begin with. Panzer might have been acquainted with Field on the outside without Lewin’s knowledge. On the other hand, I didn’t particularly want Panzer hanging around the theatre that morning; so the errand did both of us a lot of good.” “Well, I hope you were satisfied with that package of newspapers I sent you in return, as you instructed,” grinned Cronin. “How about the anonymous letter Morgan received? Was that a blind, or what?” demanded Sampson.