Then, in the nebulous light which permeated the clammy atmosphere, he turned to examine the possibilities of further progress. He had heard of such caverns as this, and knew that parts of the country were honeycombed with a vast network of such subterranean natural excavations. Some of these caves went further than even the most intrepid had ever dared to explore them: he remembered a story he had heard about Cheddar Caves, of a party which had set out to investigate a certain tunnel and had never returned, and he recalled how his fertile imagination had been fired with visionings of strange prehistoric beasts surviving in the bowels of the earth, and perhaps a race of semi-human beings similarly entombed, and how he had resolved one day to go in search of the lost explorers. But that would have been with all the armoury he wanted, suitable companions, ropes, and torches. . . . This, however, was not Cheddar, and he had nothing but his soaking clothes and the few things in his pockets. Yet, since there was no retreat towards the water, he must go the other way. He was certain that he had been carried too far down the stream for there to be any hope of a search party getting in touch with him. Behind him what he had thought was simply the ledge proved to be a low gap in the face of the rock. He crawled a little way in, and felt again the helplessness of being without the flashlight which he ought to have had with him in any case. Still, it wasn’t any use crying about it—you couldn’t weep luminous tears—so the only thing to do was to carry on and hope for the best. A distinct draught chilled his face as he wriggled along in the pitchy blackness, and his hopes began to rise again, tentatively. If the air circulated freely, it meant that somewhere there must be an outlet, and the grim doubt was whether, when he found it, it would prove to be an outlet he could use.