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 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.
“I know your immense experience, sir,” said he. “This is quite unofficial, of course, and need go no farther. But I am fairly up against it in this McPherson case. The question is, shall I make an arrest, or shall I not?”
“Meaning Mr. Ian Murdoch?”
“Yes, sir. There is really no one else when you come to think of it. That’s the advantage of this solitude. We narrow it down to a very small compass. If he did not do it, then who did?”
“What have you against him?”
He had gleaned along the same furrows as I had. There was Murdoch’s character and the mystery which seemed to hang round the man. His furious bursts of temper, as shown in the incident of the dog. The fact that he had quarrelled with McPherson in the past, and that there was some reason to think that he might have resented his attentions to Miss Bellamy. He had all my points, but no fresh ones, save that Murdoch seemed to be making every preparation for departure.
“What would my position be if I let him slip away with all this evidence against him?” The burly, phlegmatic man was sorely troubled in his mind.
“Consider,” I said, “all the essential gaps in your case. On the morning of the crime he can surely prove an alibi. He had been with his scholars till the last moment, and within a few minutes of McPherson’s appearance he came upon us from behind. Then bear in mind the absolute impossibility that he could single-handed have inflicted this outrage upon a man quite as strong as himself. Finally, there is this question of the instrument with which these injuries were inflicted.”
“What could it be but a scourge or flexible whip of some sort?”
“Have you examined the marks?” I