“Are we to understand, Sir Thomas,” he asked, “that that formula was of great value?—of greater value than the three thousand pounds?” “Call me Professor,” said the famous scientist. “Saves time—— Yes. You are to understand that! Three thousand pounds! Had it been my secret, I wouldn’t have sold it for thirty thousand pounds! That chap Spindler is an ass—or awfully ignorant of market values; had he stuck to it himself he’d have made a huge fortune out of it, one way and another. I don’t know if you two are at all up in this question of aniline dyes? You’ll know, at any rate, if you read your newspapers, that it’s a most serious question—one of rescuing a trade originally ours from its German usurpers. You know that? Very well, this young man at Farsham—clever chap, indeed!—has discovered a peculiar formula! I needn’t go into details, but I know enough to be absolutely certain, in my own mind, that Markenmore was murdered by somebody who knew that he had the formula on him, and who meant to have it for himself by hook or crook. He was probably followed down here, watched, and attacked at the lonely spot I read of in the papers.” “That presupposes that somebody in London knew what he had on him,” said Blick. “Somebody—in London or elsewhere—certainly must have known,” assented the Professor. “My own theory is that Markenmore told other people—financial speculators, perhaps, about this—and he may have shown them my opinion as an expert. But I’ll tell you my own share in the transaction. I have, as you may know, a European reputation as a chemist. Well, Markenmore wrote to me, enclosing Spindler’s formula and a handsome fee, asking me to tell him what I thought of it. I recognized the immense value of the thing at once, and I wrote out my opinion, and returned the formula with it to Markenmore. I was so anxious that the secret of the formula should be kept that I adopted unusual precautions in sending the papers (which no living soul but myself had seen while they were in my possession) to him; instead of posting them I gave them, heavily sealed, to a trusted assistant of mine—an assistant in my laboratory—who was just then going to London for a holiday, so that they might be delivered to Markenmore himself, by hand, at his office in Folgrave Court. That they were so delivered, I know. The assistant to whom I have referred, though he did not know what precisely the packet contained, knew that its contents were of supreme consequence, and, indeed, of monetary value, and he was most careful to hand the packet to Markenmore in person. And when Markenmore came down here that night, he would have these papers on him—the formula itself, and my opinion on it. I tell you again, my belief is that he let somebody else into the secret, that that somebody followed him, watched him, and murdered him! The Spindler formula is at the bottom of the whole thing!”