“Thank you,” said I. “I value a woman’s instinct in such matters. You use the word ‘they.’ You think that more than one was concerned?”

“I knew Mr. McPherson well enough to be aware that he was a brave and a strong man. No single person could ever have inflicted such an outrage upon him.”

“Might I have one word with you alone?”

“I tell you, Maud, not to mix yourself up in the matter,” cried her father angrily.

She looked at me helplessly. “What can I do?”

“The whole world will know the facts presently, so there can be no harm if I discuss them here,” said I. “I should have preferred privacy, but if your father will not allow it he must share the deliberations.” Then I spoke of the note which had been found in the dead man’s pocket. “It is sure to be produced at the inquest. May I ask you to throw any light upon it that you can?”

“I see no reason for mystery,” she answered. “We were engaged to be married, and we only kept it secret because Fitzroy’s uncle, who is very old and said to be dying, might have disinherited him if he had married against his wish. There was no other reason.”

“You could have told us,” growled Mr. Bellamy.

“So I would, father, if you had ever shown sympathy.”

“I object to my girl picking up with men outside her own station.”

“It was your prejudice against him which prevented us from telling you. As to this appointment” - she fumbled in her dress and produced a crumpled note - “it was in answer to this.”

DEAREST [ran the message]:

The old place on the beach just after sunset on Tuesday. It is the only time I can get away.

F. M.

“Tuesday was to-day, and I had meant to meet him to-night.”

I turned over the paper. “This never came by post. How did you get it?”

“I would rather not answer that question. It has really nothing to do with the matter which you are investigating. But anything which bears upon that I will most freely answer.”

She was as good as her word, but there was nothing which was helpful in our investigation. She had no reason to think that her fiance had any hidden enemy, but she admitted that she had had several warm admirers.

“May I ask if Mr. Ian Murdoch was one of them?”

She blushed and seemed confused.

“There was a time when I thought he was. But that was all changed when he understood the relations between Fitzroy and myself.”

Again the shadow round this strange man seemed to me to be taking more definite shape. His record must be examined. His rooms must be privately searched. Stackhurst was a willing collaborator, for in his mind also suspicions were forming. We returned from our visit to The Haven with the hope that one free end of this tangled skein was already in our hands.

A week passed. The inquest had thrown no light upon the matter and had been adjourned for further evidence. Stackhurst had made discreet inquiry about his subordinate, and there had been a superficial search of his room, but without result. Personally, I had gone over the whole ground again, both physically and mentally, but with no new conclusions. In all my chronicles the reader will find no case which brought me so completely to the limit of my powers. Even my imagination could conceive no solution to the mystery. And then there came the incident of the dog.

It was my old housekeeper who heard of it first by that strange wireless by which such people collect the news of the countryside.

“Sad story this, sir, about Mr. McPherson’s dog,” said she one evening.

I do not encourage such conversations, but the words arrested my attention.

“What of Mr. McPherson’s dog?”