vague, not to say visionary, character, and I doubt if you can help me. But at any rate I will explain the trouble as well as I can. In the first place, am I right in supposing that you were in some way professionally engaged in connection with that extraordinary case of murder a week or so ago—the case in which a man named Denson was found dead on the steps by the Duke of York's column?"

"Yes—and no," Hewitt answered. "I was professionally engaged on a certain matter about which you will not wish me to particularise—since it is the business of a client—and in course of it I came upon the other affair."

"Then before I ask what you know of that mysterious event, Mr. Hewitt, I will tell you my story, so that you may judge whether you are able to reveal anything, or to do anything. Of course, what I say is in the strictest confidence."

"Of course."

"I have a parishioner, a Mr. Jacob Mason, of whom I have seen very little of late years—scarcely anything at all, in fact, till a few days ago. He is fairly well to do, I believe, living a somewhat retired life in a house not far from my rectory. For many years he has laboured at natural science—chemistry in particular—and he has a very excellently fitted laboratory attached to his house. He is a widower,