"What, this rock, Mr Jack? Do you mean melted like lead and running down?"
"Of course."
"Oh, I say, Mr Jack, is this a time, with black Indians close at hand, to go stuffing a fellow with cranky tales?"
"I am only telling you the simple truth, Ned."
"But hard stone can't melt."
"Yes, it can, if the heat is great enough. This was all running like molten metal once, this part under our feet."
"And what about this where we are, sir?"
"It seems to me, Ned, as if it were the cindery froth on the top, that was full of gas and steam, so that when it cooled it left all these holes and cracks and crevices. Look at that piece lying there; only that it's of a beautiful silvery grey, it looks just like one of the pieces of cinder which pop out of the fire."
"Want a pretty good-sized fire for a piece like that to pop out of, sir," said the man scornfully.
"Well, it must have been a good-sized fire when this great mountain was in eruption, and the red-hot lava boiling over the sides of the crater and running down."
"But do you really think it ever did, sir?"
"I have no doubt about it whatever. Look at that piece lying half buried in the black sand. What is that?"
"Looks like black glass, sir," said Ned, kicking a piece of obsidian.
"Well, it is volcanic glass. How could that have been made without heat?"
"I dunno, sir. It caps me."
"You said the place was hot."
"No need to say it, sir. I'm as hot as hot. Brings me out in a prespiration."
"St! don't talk so loudly, Ned. The place echoes so."
At that moment the man laid his hand upon Jack's arm and pointed downward.
The lad followed the direction of the pointing hand, to see that a group of the blacks were coming in their direction, and for the moment Jack felt that they must be seen, until he saw that they were standing well in the shadow.
His first impulse was to catch Ned's arm, stoop down and hurry away to reach the shelter of the trees, but Ned stopped him.
"No good, sir. We should be seen. Let's go right in here."
"What, to be trapped?"
"They mightn't come in here, sir, and if they did, perhaps they couldn't find us. Anyhow they're sure to see us and come after us if we go outside."
The wisdom of the words was evident enough, and with a sigh Jack drew back with his companion, startling some birds from a shelf where they seemed to be nesting within reach of his hand, and sending them rushing out uttering their alarm notes.
"Are we in far enough, Mr Jack?" said Ned.
"No: any one could see us here. Come along."
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.