“Then I am not going to blackmail you, Thorndyke, for I have a strong conviction that an opportunity would present itself.”

“I think it very probable,” he replied with a smile. “At any rate, I know a good many methods that I should not adopt, and I think arsenic poisoning is one of them. But don’t you agree with me?”

“I suppose I do, at least in the very extreme case that you have put. But it is the only case of justifiable premeditated homicide that I can imagine; and it obviously doesn’t apply to Wallingford.”

“My dear Mayfield,” he exclaimed. “How do we know what does or does not apply to Wallingford? How do we know what he would regard as an adequate motive? We know virtually nothing about him or his affairs or about the crime itself. What we do know is that a man has apparently been murdered, and that, of the various persons who had the opportunity to commit the murder (of whom he is one) none had any intelligible motive at all. It is futile for us to argue back and forth on the insufficient knowledge that we possess. We can only docket and classify all the facts that we have and follow up each of them impartially with a perfectly open mind. But, above all, we must try to increase our stock of facts. I suppose you haven’t had time to consider that abstract of which we spoke?”

“That is really what brought me round here this evening. I haven’t had time, and I shan’t have just at present as I am starting to-morrow to take up work on the Southeastern Circuit. But I have brought the current volume of the diary, itself, if you would care to wade through it.”

“I should, certainly. The complete document is much preferable to an abstract which might leave me in the dark as to the context. But won’t you want to have your diary with you?”

“No, I shall take a short-hand note-book to use while I am away. That is, in fact, what I usually do.”

“And you don’t mind putting this very confidential document into the hands of a stranger?”

“You are not a stranger, Thorndyke. I don’t mind you, though I don’t think I would hand it to anybody else. Not that it contains anything that the whole world might not see, for I am a fairly discreet diarist. But there are references to third parties with reflections and comments that I shouldn’t care to have read by Thomas, Richard and Henry. My only fear is that you will find it rather garrulous and diffuse.”

“Better that than overcondensed and sketchy,” said he, as he took the volume from me. He turned the leaves over, and having glanced at one or two pages exclaimed: “This is something like a diary, Mayfield! Quite in the classical manner. The common, daily jottings such as most of us make, are invaluable if they are kept up regularly, but this of yours is immeasurably superior. In a hundred years’ time it will be a priceless historical work. How many volumes of it have you got?”