For a quarter of an hour after reaching a place of safety Dick could only lay on the ground panting for breath and trying to regain his strength.
His lower limbs were cramped and swollen, and when he finally stood up, his feet felt as though a thousand needles were piercing them.
"Never mind; you'll be all right by to-morrow," said old Jacob, kindly. "I'm glad we found ye in time."
"So am I, Jacob. I think, though, that Dash deserves a good bit of praise;" and he patted the dog affectionately on the head.
While resting, Dick told of the encounter with Joseph Farvel. Then he asked what had become of Menden and the others.
"They are all in camp up on the mountainside," answered Bob. "They made a tour of one small cave yesterday, but found nothing. We were all going out to-day, but went off on a hunt for you instead."
"If Robert Menden is smart he will lose no time. Joseph Farvel means to get that treasure if he can."
"Well, I reckon it's going to be a neck and neck race," said Bob. "All I hope is, that Menden proves to be the winner."
It was not until sunset that Dick found himself in the new camp. All were glad to see him and listened with deep interest to the story he had to relate.
"You have received a taste of the sort of man Farvel is," was Robert Menden's comment. "Do you wonder now why I thoroughly dislike the fellow?"
"No, I don't wonder," answered Dick; "and after this I'm going to try harder than ever to keep that treasure out of his reach."
That night both Dick and Danny slept soundly and in the morning felt once more like themselves. It was resolved that in the future, if it was possible to do so, the whole party should keep together.
"And one man must remain on guard constantly," added Robert Menden. "If not, Joseph Farvel may treat us to a disagreeable surprise."
The party had, the day before, explored a small cave but a short distance from the river. It was now decided to let Remora take them to the great Dark Cave.
The path was a winding, tortuous one, and they had to proceed with great care, especially as all wanted to avoid even the semblance of another mishap.
It was clear, and from one point where they stopped to take a rest they could see for miles. Far away to the north they beheld the church spires of San Juan, and beyond the rolling sea, shining brightly in the sunlight. On all sides were the rolling hills and sharp-backed mountains, clothed in living green of all shades.
"What an immense island for stock raising!" murmured Leander. "A fellow could have thousands of heads of cattle here. Just look at the thickness of the grass."
"This land will all be given over to coffee and sugar plantations in time," said Robert Menden. "Nine people out of ten care to raise nothing else."
They were resting under a big calabash tree laden with green fruit. Now they resumed their journey, through brush and stubble, for the trail had gradually scattered and been lost.
At last they approached a cliff all of two hundred feet in height. Before the cliff were great piles of rocks, overgrown with vines and gray moss. Behind one mass of rocks was a yawning hole not over six feet square.
"Dat is one of de doors to de Dark Cave," announced Carlos Remora. "Now we light torch, please you;" and they halted while he fired up. The torch was a stick several feet in length and smeared over with a sticky gum. Carlos carried several, and all of the others had at least one apiece, tied over his shoulder, and all carried a goodly supply of matches in addition.
The descent into the cave was a gradual one for forty or fifty feet. Beyond the opening the cavern broadened out and became much higher. At the end of the descent there was a drop of a few feet, and after this the flooring proved quite level for over half a mile.
"Have a care of de birds!" shouted Remora. He meant the bats, which were circling in all directions over their heads. Near the entrance the Dark Cave is filled with them, and sometimes they brush against the visitor with their skinny wings, producing anything but a pleasant sensation. It was a bat which had knocked out the eye of the native before mentioned.
On they went, over a flooring of dark stone, reeking with wet, mould and slime. Overhead hung stalactites of lime rock, tinged with various colors from the minerals which lie hidden in these mountains of Porto Rico. In one spot a stalactite had fallen, and they picked it up and brushed it off, to find it of a rainbow hue, beautiful beyond description.
"I should think those stalactites would alone be worth something," observed Bob. "They would make beautiful house ornaments, were they properly cleaned."
"They wouldn't stand the outer air long," answered Dick. "Such rock never does."
"Great Cæsar! what a cave!" exclaimed Don, after they had been travelling for a mile or more. "This is a regular underground world."
"You have not seen it all yet, señor," replied Carlos Remora. "Da werry long, werry broad."
All had their eyes open as they advanced, looking for a long, flat stone, with a cross cut upon it and the initials M. M. M.
Robert Menden had questioned Remora on this point, but the Porto Rican had assured him that he had never seen such a stone, and added that he doubted if there were any carvings in the cave. "Only werry few come here," he had concluded. "Most men afraid of de dark."
"It would be very beastly down here without a light," said Menden, as they paused in front of a yawning hole a dozen or more feet in diameter. "Where does that lead to, Remora?"
The native shook his head. "Can't say about dat. Nobody ever go down dem. Hark!"
He picked up a loose stone and hurled it down the opening. They heard it rebound from one wall to another a dozen times, the sound growing fainter and fainter until it died out altogether.
"That's awful!" whispered Leander, as he drew back. "That must lead to the center of the earth."
"Nonsense, Leander," replied Dick. "But it's pretty deep, I admit."
"Are there many such holes?" asked Menden.
"So many," the guide held up the fingers of both hands. "But dis is de big one. Everybody afraid of him;" and he walked on, unwilling even to remain in the vicinity.
From a distance came the sound of falling water, and presently they came to a tiny waterfall. Below was a pool of inky blackness and a small underground watercourse, which disappeared under the wall of the cavern a hundred yards away.
"I reckon dis knocks out de Mammoth Cave uf Kentucky," said Danny. "Why yer could build a hull city down here, dat's wot yer could!"
They had now reached the end of one branch of the cave, and turned back to try another branch. Soon they reached a point where the flooring was very wet and the drops of water came down steadily.
"We under ribber now," explained Remora. "Some day water come down in big heap and fill cave."
"Where does this water go to?" asked Don.
"Go to little ribber at waterfall."
"I see. Do you think it safe here with this water coming down?"
At this question the guide merely shrugged his shoulders. To his way of thinking no portion of the cave was safe, and only the thought of getting good pay for his services made him stick to the exploring party.
By one o'clock everybody was tremendously hungry, and all hands sat down in a comparatively dry spot to consume the lunch which had been brought along. There was also a pot of coffee, and by holding this over a couple of torches it was warmed up, and each had a cup of the beverage which, as old Jacob expressed it, "struck right ter hum in thet cold, forlorn region."
"So far, no luck," said Robert Menden, in disappointed tones. "I'm afraid I've led you all on something of a wild-goose chase."
"You musn't get discouraged too quickly," replied Dick. "Remember, treasure boxes aren't to be picked up every day."
"I had no idea that the caves of Porto Rico were so vast. The more I see of them the more I am astonished."
"I've been thinking that perhaps the treasure is down in a cave below this," put in Bob. "We ought to try some of those holes before we leave."