Rhodes made no answer. For some moments we stood there in breathless expectation; but that low mysterious sound did not come again.
I said:
"What was that?"
"I wish that I knew, Bill. It was faint, it was—well, rather strange."
"It was more than that," I told him. "It seemed to me to be hollow—like the sound of some great door suddenly closing."
My companion looked at me rather quickly.
"Think so, Bill?" he said. "I thought 'twas like the sound of something falling."
There was a pause, one of many moments, during which pause we stood listening and waiting; but the gallery remained as silent as though it had never known the tread of any living thing.
"Well, Bill," said Milton Rhodes suddenly, "we shall never learn what Drome means if we stay in this spot. As for the creepers, I am going to leave mine here."
The place where he put them, a jutting piece of rock, was a conspicuous one; no one passing along the tunnel could possibly fail to notice the objects resting there. Mine I placed beside them, wondering as I did so if I should ever see this spot again.