“Dead, sir. Died of grief for its master.”

“Who told you this?”

“Why, sir, everyone is talking of it. It took on terrible, and has eaten nothing for a week. Then to-day two of the young gentlemen from The Gables found it dead - down on the beach, sir, at the very place where its master met his end.”

“At the very place.” The words stood out clear in my memory. Some dim perception that the matter was vital rose in my mind. That the dog should die was after the beautiful, faithful nature of dogs. But “in the very place”! Why should this lonely beach be fatal to it? Was it possible that it also had been sacrificed to some revengeful feud? Was it possible- -? Yes, the perception was dim, but already something was building up in my mind. In a few minutes I was on my way to The Gables, where I found Stackhurst in his study. At my request he sent for Sudbury and Blount, the two students who had found the dog.

“Yes, it lay on the very edge of the pool,” said one of them. “It must have followed the trail of its dead master.”

I saw the faithful little creature, an Airedale terrier, laid out upon the mat in the hall. The body was stiff and rigid, the eyes projecting, and the limbs contorted. There was agony in every line of it.

From The Gables I walked down to the bathing-pool. The sun had sunk and the shadow of the great cliff lay black across the water, which glimmered dully like a sheet of lead. The place was deserted and there was no sign of life save for two sea-birds circling and screaming overhead. In the fading light I could dimly make out the little dog’s spoor upon the sand round the very rock on which his master’s towel had been laid. For a long time I stood in deep meditation while the shadows grew darker around me. My mind was filled with racing thoughts. You have known what it was to be in a nightmare in which you feel that there is some all-important thing for which you search and which you know is there, though it remains forever just beyond your reach. That was how I felt that evening as I stood alone by that place of death. Then at last I turned and walked slowly homeward.

I had just reached the top of the path when it came to me. Like a flash, I remembered the thing for which I had so eagerly and vainly grasped. You will know, or Watson has written in vain, that I hold a vast store of out-of-the-way knowledge without scientific system, but very available for the needs of my work. My mind is like a crowded box-room with packets of all sorts stowed away therein - so many that I may well have but a vague perception of what was there. I had known that there was something which might bear upon this matter. It was still vague, but at least I knew how I could make it clear. It was monstrous, incredible, and yet it was always a possibility. I would test it to the full.

There is a great garret in my little house which is stuffed with books. It was into this that I plunged and rummaged for an hour. At the end of that time I emerged with a little chocolate and silver volume. Eagerly I turned up the chapter of which I had a dim remembrance. Yes, it was indeed a far-fetched and unlikely proposition, and yet I could not be at rest until I had made sure if it might, indeed, be so. It was late when I retired, with my mind eagerly awaiting the work of the morrow.

But that work met with an annoying interruption. I had hardly swallowed my early cup of tea and was starting for the beach when I had a call from Inspector Bardle of the Sussex Constabulary - a steady, solid, bovine man with thoughtful eyes, which looked at me now with a very troubled expression.