Off we started again in the direction from which the faint murmur seemed to come, groping our way as before along the rocky walls. As we went it became more and more audible, till at last it seemed quite loud in the quiet. On, yet on; now we could distinctly make out the unmistakable swirl of rushing water. And yet how could there be running water in the bowels of the earth? Now we were quite near to it, and Good, who was leading, swore that he could smell it.
"Go gently, Good," said Sir Henry, "we must be close." Splash! and a cry from Good.
He had fallen in.
"Good! Good! where are you?" we shouted, in terrified distress. To our intense relief an answer came back in a choky voice.
"All right; I've got hold of a rock. Strike a light to show me where you are."
Hastily I lit the last remaining match. Its faint gleam discovered to us a dark mass of water running at our feet. How wide it was we could not see, but there, some way out, was the dark form of our companion hanging on to a projecting rock.
"Stand clear to catch me," sung out Good. "I must swim for it."
Then we heard a splash, and a great struggle. Another minute and he had grabbed at and caught Sir Henry's outstretched hand, and we had pulled him up high and dry into the tunnel.
"My word!" he said, between his gasps, "that was touch and go. If I hadn't caught that rock, and known how to swim, I should have been done. It runs like a mill-race, and I could feel no bottom."
We dared not follow the banks of the subterranean river for fear lest we should fall into it again in the dark-
