What the Romans had done was to scoop out the interior of a nodule of hill, much as we now dig out the inside of a Stilton cheese, and leave the walls intact. But there existed this difference: that the walls were not like a cheese-rind, that could be pierced through. They were but portions of the mountain, into which, by adits from the crater, the miners had burrowed. Most of these old tunnels were choked, some hidden under slides of rubble, but one gaped black, and it was into this that the Five Saints had entered according to legend, and Gwen also. And now Pabo was about to penetrate as well. Doubt of the reality of the discovery made by the hermit had departed. He was fully convinced that he would light on the hoard. His sole fear left was he should forget the directions he had seen traced on the plank. There was little wind now, below in this bowl. He struck flint and steel together and obtained a light. Then he kindled his wax taper, signed himself with the cross, and entered the cave. For some way in, the floor was covered with stones that had been thrown in. The roof was higher than his head and was arched. This was no natural cavern like that under Careg Cennen. This was cut by man's hand, out of rock very different in character, color, and texture from the limestone. The light from his taper glittered in the water that trickled over the sides, and in the pools that here and there lay in the footway. There were no stalagmites. Pabo could distinguish the marks of the picks used to excavate the adit. All at once he was startled by a rushing and whistling. He drew back, and past him swept legions of bats that had hitherto lived undisturbed in this cave. They came back, flickered near his face, threatened his light, and he shouted and threw stones. Then--he saw, heard them no more. They had issued from the portal and had gone to hunt under the open sky. Now the ground rose; there had been an accumulation of soil, and he was forced to bend low to pass on. But presently the floor sank and the vault was loftier, and he pursued his course erect. The ground now was hard rock, not earth, and it rang under his steps. It was also dry. The air was intensely still. The candle cast but a feeble light, and that but imperfectly illumined the way before him. He could best see by holding it above his head, yet was able to do this only where the arched roof was high, and he ever feared lest it should strike on a rock and become extinguished.