CHAPTER IX

SURROUNDED BY MYSTERIES

"WHAT about the swivel gun in the camp; could it be heard as far away as this, do you think, Dick?" asked Roger, as though a new idea had flashed into his mind.

The other shook his head in the negative.

"Hardly," he replied, "and, even if it were possible, you forget that it is only when the wind picks up from this new quarter that we hear the sound."

"And that is from the northwest, while our camp lies back yonder, more in the northeast," admitted Roger. "I admit that, when I spoke, I was picturing a horde of half-naked Indians trying to carry the camp by storm, and Captain Clark rallying his defenders behind the breastworks we built out of pine logs and earth."

"It is nothing of that sort, I am sure," said Dick, "though, when you ask me to explain the origin of that sound, I am as much in the dark as you."

"Well, as our way lies toward the northwest," remarked Roger, "there's some satisfaction in knowing we will be getting closer to the mystery all the time."

"I am glad to see that you are not afraid, Roger."

"There can be no telling what state I may be in before we get out of this strange country," admitted Roger, laughingly. But Dick knew him too well to think he could show any sign of fear.

Mayhew said little, for he was naturally a man of few words. He could not be reckoned as above the average of his class; and possibly there was a well-defined streak of superstition in his nature, even as it was to be found in other bordermen of the day.

Left to his own devices, perhaps Mayhew would have much preferred not to advance any further into this unknown and terrifying land. He had no particular desire to learn whether the stories told were true or false; and the camp that had been left behind held many alluring claims to his regard.

But his honor as a reliable borderman was in the balance. He could not forget that, chiefly through his carelessness, there had been lost a paper entrusted to his charge, which was of the utmost value to these lads.

Hence he was firmly resolved to stand by them, no matter what happened, for the object of their venture was to duplicate the document he had allowed to slip out of his hands.

"There is the river over yonder; I can see the sun shining on the tumbling water of one of the numerous cataracts," Dick commented, as he pointed in the direction indicated.

"The Indians have a story to the effect that it springs from a great fresh water inland sea lying over the ridges somewhere," Roger remarked, as he stood looking at the foaming surface of the stream. "Do you believe there is any truth in that account, Dick; or can it be set down as a fable, like this Evil Spirit of the land?"

"Oh! it seems that others have looked upon the great lake at a distance, French traders and voyageurs, and they say it is surely there," the other affirmed. "Who knows but that, before we see our good friend Captain Lewis again, we, too, may be able to boast of having set eyes on the mirror lake."

"Captain Lewis told me he would give much for the privilege of accompanying us; but duty would not permit," Roger observed.

"Yes, he cannot forget that the President committed the fate of this exploration into his hands, and looks to him to supply all the information possible," said Dick. "So Captain Lewis, like an honorable and conscientious gentleman, will not take any unnecessary risk in order to gratify his curiosity. His place is there in the camp."

Feeling hungry as noon arrived they munched some of the hard pemmican while keeping on the move. That suited the impetuous Roger, for it was virtually "killing two birds with one stone"; they satisfied their hunger, and yet found no reason to delay their progress in order to do so.

Mayhew still found a way to discern the trail of those who had gone over this same ground ahead of them. Indeed, it would have to be a faint track that his practiced eyes failed to discover.

All this while there had been a perceptible change in the character of the country. It kept getting more rocky, and wilder the further they advanced. Roger was constantly looking on all sides as though expecting to discover some new and remarkable thing at any minute. Indeed, Dick was also considerably worked up over the strange conditions surrounding them, and made up his mind not to be surprised at anything that might happen.

It was when they were in this receptive frame of mind that something occurred out of the common, to alarm them. Roger was the first to hear a sound, though Dick, seeing him come to a sudden halt, and stand in an attitude of listening, also began to catch it.

"Hold on, Benjamin," said Dick, in a low tone, "there's something queer going on around us that we must look into before proceeding further."

"Of all the strange things, did you ever hear such a terrible groaning before, Dick?" asked Roger. "I wonder if it has anything to do with the noise we caught before, that was so like thunder."

"Hardly, for that was surely far away, while this is close by," replied the other boy, with a puzzled look on his sun-browned face.

Roger even took off his foxskin cap, as though he imagined that the dangling flaps which he used to keep his ears warm in bitter weather might interfere with his sense of hearing.

Again those strange groanings made themselves heard. This time both boys managed to locate the sound as coming from the right. That was at least one point gained, and it was toward that quarter they now turned their attention.

If they had been trying to pick out the most difficult spot in all the wild vicinity, they would have selected that toward which their attention was now directed. The rocks seemed to be piled on one another in hap-hazard fashion. Here and there they formed deep chasms, the sides of which were so precipitous as to be incapable of being scaled by any creature short of a monkey.

"It comes welling up out of the ground itself, Dick," ventured Roger, presently, with awe in his manner, as though, after all, he might be wondering whether there could be any truth in the tales told of the Evil Spirit that haunted these weird ridges, speaking in thunder tones at one minute, and with dreadful groanings the next.

Dick believed in taking the bull by the horns in a case like this.

"We must look into it, Roger; it would never do for us to say we had been driven away through hearing some mysterious sound that we did not understand."

"There it comes again, Dick, and louder than before. What can it be?"

"The hot spring seemed to tell of some sort of fires away under the surface of the ground," the other said, reflectively, "and it might be that this is more of the hot vapor pressing up through holes in the rocks."

"But how like human groans the sounds are!" marveled Roger.

"I agree with you," his companion returned, "but have you forgotten the time we heard those terrifying noises coming from the old mill that stood a mile away from our homes, and how some of our companions fled, but we had the hardihood to go inside and look around?"

"Yes," interjected Roger, quickly, "and we found the wind forced a way through a crack between two logs, and made the doleful noise! It may be something like that here."

"We will soon know, because I mean to make my way over there and take a good look around," announced Dick.

"If you go I will keep you company!" declared Roger, just as stoutly, as he gave a glance down, in order to make sure that the powder in the pan of his flint-lock rifle had not been disturbed, and that the weapon was ready for instant use.

Together they advanced, with Mayhew keeping them company. All were constantly on the alert for signs of treachery and danger. Those who dealt with the tricky red sons of the forest in the pioneer days learned to be always on the watch.

Now the sounds ceased, and the boys exchanged looks, as if asking each other whether this could have anything to do with their arrival. Were hostile eyes watching them from some rocky covert; and would a signal be given to launch an attack?

Dick, examining what lay just beyond, came to a conclusion.

"There is a gaping hole yonder, you see, Roger?" he noted.

"Where the rocks seem to drop straight down, you mean?" replied the other.

"Yes, and it is out of that hole the sounds came. Let us stand here, and wait to see if we can hear them again."

They had not long to wait. Even as they stood listening intently, there came once more a long-drawn moan, which was followed by others. Then succeeded a rattling sound as though some heavy body were endeavoring to creep up the slanting rock, only to slip back again. They even heard the thud that seemed to announce the end of the vain attempt.

Still it was all unintelligible to both Dick and Roger. While the groans continued to well up out of the basin, they again started to creep forward. The brink was within plain sight, and in another minute they would be in position to peer over the edge.

What new and terrifying wonder they might discover there they could not even guess, yet it was with a thrill that the lads kept on, covering the intervening rock foot by foot.

They reached the brink together, and both immediately thrust out their heads to take the first look. Only for a brief space of time did they stare downward, and then, just as a cautious tortoise might draw back his head within his shell, Dick and his companion retreated.

"Oh!" gasped Roger, as he turned his face, filled with perplexity, toward the other, "did you see what it was, Dick?"

"After all, nothing so strange as we thought," replied the other. "Instead of a supernatural happening, it was real human groans we heard. There are men trapped in that hole, and they have tried again and again to climb up, always to slip back again. They must he battered, and nearly starved, which would be enough to make them groan, I think."

"But, Dick, I saw one of them plainly, and I knew him, too!" urged Roger, bluntly.

"Then you saw more than I did," the other told him. "From the fact that they are dressed in buckskin I knew they must be hunters or trappers, but supposed it would turn out that they were French voyageurs, such as have roamed throughout the Northwest country since the time of Pontiac. Who was the man you saw, Roger?"

"It was surely Thomas Hardy, one of the men who accompanied Jasper Williams," said Roger, showing much concern. "And I believe the other to be Mordaunt, the second frontiersman and trapper. But there is no third in the party. What can have become of Williams? If he is dead there is an end to all our hopes. Oh, Dick, I am afraid!"

Dick's face had also lost much of its customary color, for a spasm of alarm had attacked his bold heart when his companion thus voiced his fears.