"Not likely, Ned. If they do we must go farther into its depths." "Ugh!" cried the man with a shudder. "I want to get out of the hole. It's hot and steamy, and unnatural. I believe some of the melted stuff came out this way." "What, the molten lava? Of course," said Jack coolly. "I don't understand much about it, but it's plain enough that this was all liquid molten matter once, and that it ran out along here." "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."