They went on inward for another twenty yards, the mouth of the entrance still being in full view. It was awkward travelling, the black sand having given place to loose pieces of scoria and obsidian, some pieces of which crackled under their boots, and took revenge by entering into the soles. As they went in the place widened out, but remained much about the same height overhead, the highest portions of the roof being nearly within touch of Ned's hand. Here the latter stopped again. "Don't let's go any farther, sir," he said nervously. "Don't you feel a bit frightened?" "Of course I do. It would be horrible if they caught us again. They would kill us." "Yes, sir; most likely," said Ned. "Be awkward, wouldn't it? But don't you feel scared-like about this great black hole?" "Scared? No; I like it, Ned." "Oh, no, you don't, sir. You can't. Don't say that. There! There it is again. Just over your head." He shrank back with his fist doubled as if prepared to strike. "What is it?" cried Jack, startled now. "I dunno, sir. Let's go back," cried the man in an agitated whisper. "It's very horrid though. There's lots of 'em shuffling and scrambling about in the cracks and holes, staring at you with their wicked-looking eyes, and more 'n once I've seen 'em flapping their wings. I don't like it. Let's go back." "Go back to be taken? Impossible. Look, they are only bats." "Bats with wings a yard across, sir? Oh, come, I know better than that." "What are they then?" said Jack angrily. "Oh, I dunno, sir. Something horrid as lives in this dreadful place. They make me feel creepy all down my back. I'd rather have a set-to with one of the ugliest blacks yonder." "I tell you they are bats--the great fruit bats. Why, Captain Bradleigh pointed them out to me the other night, flying overhead in the darkness just like big crows." "Are you sure, sir? There, look at that thing staring down at you and making noises. Mind, pray, Mr Jack, sir, or he'll have you. Perhaps their bite's poison." "They will not bite if we leave them alone. They are flying foxes." "Flying wolves, I think, sir. I say, hadn't we better go back?" "No," said Jack firmly. "Why, Ned, are you going to turn coward?" "Hope not, sir; and that's what worries me--me being a man and feeling as I do, while you're only a boy and don't seem to mind a bit. I wouldn't care so much if you were frightened too." "Well, I am frightened, Ned--horribly frightened, but not of the flying foxes." "But you don't seem to mind what might be farther in, sir," said Ned, staring wildly into the darkness ahead. "Oh yes, I do," replied Jack. "I'm afraid we might slip down into some horrible black pit; but we need not if we're careful." "Ah, you don't seem to understand me, sir, and I don't quite understand myself. I suppose it's from only being half myself again, for one of my arms is no good at all. That's what makes me feel a bit cowardly like."