The same thought had crossed my own mind. It was not as if the Barrymores had taken us into their confidence. Their secret had been forced from them. The man was a danger to the community, an unmitigated scoundrel for whom there was neither pity nor excuse. We were only doing our duty in taking this chance of putting him back where he could do no harm. With his brutal and violent nature, others would have to pay the price if we held our hands. Any night, for example, our neighbours the Stapletons might be attacked by him, and it may have been the thought of this which made Sir Henry so keen upon the adventure.

“I will come,” said I.

“Then get your revolver and put on your boots. The sooner we start the better, as the fellow may put out his light and be off.”

In five minutes we were outside the door, starting upon our expedition. We hurried through the dark shrubbery, amid the dull moaning of the autumn wind and the rustle of the falling leaves. The night air was heavy with the smell of damp and decay. Now and again the moon peeped out for an instant, but clouds were driving over the face of the sky, and just as we came out on the moor a thin rain began to fall. The light still burned steadily in front.

“Are you armed?” I asked.

“I have a hunting-crop.”

“We must close in on him rapidly, for he is said to be a desperate fellow. We shall take him by surprise and have him at our mercy before he can resist.”

“I say, Watson,” said the baronet, “what would Holmes say to this? How about that hour of darkness in which the power of evil is exalted?”

As if in answer to his words there rose suddenly out of the vast gloom of the moor that strange cry which I had already heard upon the borders of the great Grimpen Mire. It came with the wind through the silence of the night, a long, deep mutter, then a rising howl, and then the sad moan in which it died away. Again and again it sounded, the whole air throbbing with it, strident, wild, and menacing. The baronet caught my sleeve and his face glimmered white through the darkness.

“My God, what’s that, Watson?”

“I don’t know. It’s a sound they have on the moor. I heard it once before.”

It died away, and an absolute silence closed in upon us. We stood straining our ears, but nothing came.

“Watson,” said the baronet, “it was the cry of a hound.”

My blood ran cold in my veins, for there was a break in his voice which told of the sudden horror which had seized him.

“What do they call this sound?” he asked.

“Who?”

“The folk on the countryside.”

“Oh, they are ignorant people. Why should you mind what they call it?”