The pot had just begun to bubble when I heard his voice calling to me from the bank, where he had wandered away without my noticing. I ran up.
“Come and listen,” he said, “and see what you make of it.” He held his hand cupwise to his ear, as so often before.
“Now do you hear anything?” he asked, watching me curiously.
We stood there, listening attentively together. At first I heard only the deep note of the water and the hissings rising from its turbulent surface. The willows, for once, were motionless and silent. Then a sound began to reach my ears faintly, a peculiar sound—something like the humming of a distant gong. It seemed to come across to us in the darkness from the waste of swamps and willows opposite. It was repeated at regular intervals, but it was certainly neither the sound of a bell nor the hooting of a distant steamer. I can liken it to nothing so much as to the sound of an immense gong, suspended far up in the sky, repeating incessantly its muffled metallic note, soft and musical, as it was repeatedly struck. My heart quickened as I listened.
“I’ve heard it all day,” said my companion. “While you slept this afternoon it came all round the island. I hunted it down, but could never get near enough to see—to localize it correctly. Sometimes it was overhead, and sometimes it seemed under the water. Once or twice, too, I could have sworn it was not outside at all, but within myself—you know—the way a sound in the fourth dimension is supposed to come.”
I was too much puzzled to pay much attention to his words. I listened carefully, striving to associate it with any known familiar sound I could think of, but without success. It changed in the direction, too, coming nearer, and then sinking utterly away into remote distance. I cannot say that it was ominous in quality, because to me it seemed distinctly musical, yet I must admit it set going a distressing feeling that made me wish I had never heard it.
“The wind blowing in those sand-funnels,” I said determined to find an explanation, “or the bushes rubbing together after the storm perhaps.”
“It comes off the whole swamp,” my friend answered. “It comes from everywhere at once.” He ignored my explanations. “It comes from the willow bushes somehow—”
“But now the wind has dropped,” I objected. “The willows can hardly make a noise by themselves, can they?”
His answer frightened me, first because I had dreaded it, and secondly, because I knew intuitively it was true.