“To be sure it did, Mas’r Harry; I saw where it went off under a bit of a tunnel just before we got to that horrible great place.”

“Then the cavern must branch off there, Tom,” I said. “That must be the part for us to explore.”

“Very good, Mas’r Harry, when you like; but in case of an accident, and I don’t come out any more, I think I’ll tell the truth before I go in: I said I wasn’t, Mas’r Harry, but I was awful scared and cold and creepy, but I think I shall be better this time; so when you’re ready I am.”

I expressed my readiness, and in spite of fatigue we stepped onward again till the darkness compelled us to stop and light candles, when, knowing now that there were no very great perils in the path, we made far more progress, and in a very short time arrived at the spot where Tom had seen that the bed of the stream took a fresh direction.

It was just as he had intimated: it suddenly turned off to the left, but beneath the shelving rock where we stood holding down our candles as far as we could reach; and if we wished to explore farther there was nothing for it but to scramble down some forty feet to where the water ran murmuring amongst the blocks of stone, here all glazed over with the stalagmitic concretion that had dripped from the roof.

I led the way, and with very little difficulty stood at last by the stream, when Tom followed, and we slowly proceeded along its rocky bed till at the end of a few yards we came to the turn where it came gushing out of a dark arch, some six feet high and double that width, the water looking black and deep as it filled the arch from side to side, running swiftly—a river of ink in appearance.

“Tom,” I said dreamily, “we must explore this dark tunnel.”

“Very well, Mas’r Harry,” he said in resigned tones.

And when a few minutes after I turned to look at him, he was leaning against a rock and removing his shoes and stockings.

“What are you doing?” I said.