Bob chose to consider this a direct challenge.
"I expect that it would be queer if we didn't make some sort of effort to find out what the light means. Where is it, Frank?" he remarked, with perfect coolness.
"Well, it must have gone out while you were speaking, Bob, as sure as anything," the other replied. "But I saw it, I give you my word I did. Huh! there she comes again, just like it was before. Step over here; the spur of the rock is in your way there. Now look straight up. Get it?"
"Easy, Frank. A fellow might think it was a star, if he didn't know the mountain was there. Now it's getting bigger right along."
"That's so, Bob. And yet it doesn't seem to be a fire, does it?"
"More like a lantern to me," declared the Kentucky boy. "Say, what d'ye reckon anybody could want a lantern up there for? Can you see any swinging motion to the light Frank?"
"It does seem to move, now and then, for a fact," admitted the other, after watching the gleam for a short time.
"About like a brakeman might swing his lantern if he was on a freight train in a black night, eh?" continued Bob.
"Hello! I see now what you're aiming at, Bob; you've just got a notion in your head that the lantern is being used for signalling purposes."
"Well, does that strike you as silly?" demanded Bob Archer.
"Silly? Hum! well, perhaps not, because it may be the right explanation of the thing. But whatever would anybody up there be signalling for, and who to, Bob?"
"There you've got me," laughed the other. "I'm not so far along as that yet. P'raps it might be one of the rustlers, telling something to another of the same stripe, who is located in camp out yonder on the plain. Then, again, how do we know but what it might be that Peg Grant lot? And Lopez. Don't forget little Lopez, Frank. Prospectors could have a lantern; in fact, I understand they often do carry such a thing along with 'em when they go into the mountains to pan for dust in the creek beds."
"So," said Frank, who evidently was doing considerable thinking.
They stood there for some little time, looking up at the light. Bob was merely indulging in various speculations regarding its source. On the other hand Frank busied himself in locating the strange glow, so that he might be able to know when he reached the spot, in case it was invisible at the time they arrived.
"Do we go?" asked Bob, when he, too, found his impatience getting the better of him; whereupon Frank, who had evidently been waiting for some sign, immediately took him up on it.
"If you're ready, we'll start right away," he said, quietly. "Luckily I've been studying the face of Thunder Mountain at times during the afternoon, and I reckon I can pilot the expedition all right."
But when Frank said this so confidently he failed to consider the intense darkness that might baffle all his plans of campaign. Still, Bob had the utmost confidence in his chum's ability to pull out of any ordinary difficulty. And, since his Kentucky spirit had been fully aroused, he was ready to accompany Frank anywhere, at any time.
Before they had been ten minutes on the way each of the boys sincerely wished that the idea to investigate had never appealed to them, for they began to have a rough time of it. But both were too proud to admit the fact, and so they kept crawling along over the rocks with their rifles slung on their backs, at times finding it necessary to clutch hold of bushes or saplings in order to save themselves from some tumble into holes, the actual depth of which they had no means of even guessing in the darkness.
The light was gone. Of course that might not mean it had vanished entirely; but at least it could no longer be seen by the boys who were climbing upward.
Bob was hoping his comrade would propose that they call it off, and proceed to spend the balance of the night in the first comfortable nook they ran across. But Frank himself was loath to give the first sign of a backdown. Consequently they continued the laborious task which was likely to bring no reward in its train, only the satisfaction of knowing they had accomplished the duty which they had in mind at the time of the start.
An hour must surely have gone since they first left the little green glade where the horses were staked out, and their supplies cached.
Bob found himself blown, and trembling all over with fatigue, because of the unusual exertion. The heat, too, was troublesome. But not for worlds would he be the first to complain. Frank was setting the pace, and he must be the one to call a halt.
"Phew! this is rough sledding," remarked Frank, finally, as he stopped to wipe his streaming face.
Of course Bob also came to a halt.
"Well, it is for a fact," he admitted with a little dry chuckle; for he felt really pleased to think that he had held out so long, and forced Frank to "show his hand."
"Seems to me we ought to have struck something," suggested Frank.
"Do you really mean you think we've come far enough for that?" questioned Bob.
"I reckon we have, though it's so dark I can't be dead sure. You don't happen to glimpse anything queer around here, do you, Bob?" and while speaking Frank, perhaps unconsciously, lowered his voice more or less.
"Nary a thing," replied the other, breathing fast, as if to make up for lost time.
"And I don't get any whiff of smoke, do you?" continued Frank.
"Oh! you're thinking about that volcano business again, eh?" chuckled Bob. "Nothing doing, Frank. Gee! we must be up pretty high here!"
"Feels like it," returned the prairie boy, accustomed to the heavier air of the lower levels at all times. "Makes me breathe faster, you know. But that was a hot old climb, Bob."
"All black up yonder in the sky, with never a star showing," observed the boy from Kentucky.
"Oh! we're going to get it, sooner or later," declared Frank, cheerfully. "Can't escape a ducking, I take it. But here we are, half way up old Thunder Mountain, and not a thing to show for our work. That's what I call tough!"
"Got enough?" asked his chum, invitingly.
"You mean of course for to-night only, because you'd never think of such a thing as giving up the game so early, Bob?"
"Well, I was only going to make a little suggestion," returned the other.
"Hit her up, then; though perhaps I could guess what it's like, Bob."
"All right then. You know what I mean—and that since we're away up here, we might as well make up our minds to hunt an overhanging ledge, and take a nap. But say, what're you sniffing that way for, Frank?"
"Just imagined that I got a faint whiff of smoke; but of course it was all in my eye," replied the other.
"Was it? I tell you I had a scent of it myself right then," declared the taller lad, showing signs of considerable excitement.
"Seems to come and go, then, for I don't get it any more. What was it like, Bob? Did you ever smell sulphur burning?"
"Lots of times, and helped to use it too, disinfecting," replied Bob, readily. "Spent months with my uncle, who is a doctor in Cincinnati, during an epidemic, and he often had to clean out rookeries just to stamp out the disease. But this wasn't any sulphur odor I caught, Frank."
"Then you could recognize it; eh?" asked his chum.
"It was burning wood, I give you my word for that," replied Bob, firmly.
"Hum. That sounds more like it. We'll let the volcano matter sizzle for a little while, and look around for something smaller. Burning wood must mean a fire, Bob!"
"That's what they say, always; where there's smoke there must be fire. But it seems to me we ought to see such a thing on this black night, Frank."
"Unless it's hidden, as we make our cooking fire; or else the blaze is at the last gasp. Then, after all, we may have been a little off about that light we saw," Frank continued.
"The one we said was a lantern? Then you think, now, it might have been a fire?" questioned the Kentucky lad.
"Well, I just don't know what to think. But let's look around a bit, and see if we can locate this fire," Frank suggested.
After moving around for a short time as well as the darkness allowed the two boys came together again.
"No luck, eh?" questioned Frank.
"Didn't find a thing; but I stumbled over a creek and came near taking a header down-grade that would have made that plunge of Peg's take a back seat. Just in the nick of time I managed to grab a little tree. Phew! it shook me up, though," and Bob rubbed one of his shins as though he might have "barked" it at the time of the encounter.
"Same here; only I didn't happen to fall," replied Frank.
"So it seems as if we were no better off than before," remarked Bob, dejectedly.
"We've learned where the fire isn't, if that's any satisfaction to us," chuckled his chum, trying to make the best of a bad bargain.
"And that smoke smells so meaning-like, it's sure a shame we can't just get a line on where it comes from," Bob went on to say.
Frank seemed to catch a significance in his words, for he turned sharply on his companion, saying:
"Look here, have you been getting a whiff of it again, Bob?"
"Why, yes, several of 'em in fact, Frank," replied the other, in what seemed to be a surprised tone. "But what does that matter, when neither of us can find any fire around? I sniffed and sniffed, but although I just turned my eyes in every direction not even a tiny spark could I see. And that happened just three times, Frank."
"What! do you mean you smelled smoke three separate times since you left me?" demanded the saddle boy.
"I'm sure it must have been three, because it was between the first and second times that I tripped. Yes, and always in just the same place too, which was queer enough."
"That sounds kind of encouraging, Bob," declared Frank.
"Do you think so?" asked the other, puzzled to account for Frank's newly awakened interest. "Tell me why, won't you, please, Frank?"
"Sure, after you have answered me a question," Frank promptly remarked.
"All right, let's have it, then," his chum returned.
"Do you think you could find that exact spot again?" asked Frank.
"Meaning where I sniffed that smoke each time? Why, I guess I can, because I went back there twice, all right. Couldn't be quite satisfied that there wasn'tsomethingaround there I ought to discover. But it turned out a fizzle, Frank."
"Perhaps it wouldn't be so unkind to me, though," the Western boy declared. "Take me to that place, Bob, and right away. It strikes me I'd just like to get another little whiff of that same wood smell, myself. It wouldn't be the first time I'd followed up a smoke trail."
"Gracious! that sounds interesting, and I hope you can do it, Frank!" breathed Bob, his admiration for his chum awakening once more.
"First of all, get me to that place. Lead off, and I'll be close at your heels. And, Bob, don't forget that spot where you came near having your tumble. Keep your level head about you."
"I'll sure try to, Frank. Come on then."
Bob led the way through the darkness. Although he had been out West for so short a time Bob Archer was rapidly learning the ways practiced by those who live close to Nature. He began to observe always all that he saw, and in such a way that he could describe it again, in every detail.
And so it chanced that, having marked his course when coming back after his unsuccessful search for the fire, he was able, not only to lead his comrade thither, but to warn him every time they approached a dangerous slide, where a trip might hurl one some hundreds of feet down the face of Thunder Mountain.
"Here is the place, Frank," Bob suddenly said, in a cautious whisper.
"Are you sure of it?" asked Frank, in the same low voice.
"Why, try for yourself, and see if you can't get a whiff of smoke right now," Bob replied.
"You're right, because I caught it just then; but I reckon the wind must be changing some, for it's gone again," Frank remarked.
"You never spoke truer words, Frank, because I can hear the breeze beginning to shake the leaves in the trees up yonder, and it wasn't doing that before."
Bob pointed upwards as he said this cautiously. And Frank, always watchful, noticed a certain fact. The trees were so situated that they could be said to lie almost in a direct Southeast line from where he and Bob stood! This might appear to be a very small matter, and hardly worthy of notice; but according to Frank's view it was apt to prove of considerable moment, in view of what was likely to follow.
"Well, as the smoke's gone again, let's see if we can locate it by moving a little this way," and Frank led off as he spoke, with Bob following.
Both lads were very cautious now. Even Bob, greenhorn as he was, so far as Western ways were concerned, understood the need of care when approaching a camp that might be occupied by enemies. And as for Frank, he had not been in the company of an old ranger like Hank Coombs many times without learning considerable.
They had not been moving in the new direction more than five minutes when Bob reached out his hand and clutched the sleeve of his chum's jacket.
"What is it?" asked the leader, stopping short, and crouching there.
"I got it again, Frank," whispered the Kentucky boy, eagerly.
"Sure," replied his comrade, immediately. "Why, I've been smelling smoke for more'n a whole minute now. And I'm following it up, foot by foot."
"Oh!" murmured Bob, taken aback by this intelligence.
"Don't say a word above your breath, Bob. Whoever it is can't be far away now. We may run in on 'em any minute, you know," and as if to emphasize the need of caution Frank drew his chum close while he whispered these words directly in his ear.
Bob did not make any verbal reply; but he gave the other's sleeve a jerk that was intended to tell Frank he understood, and would be careful. Then they moved along again.
It was no easy task making progress through the darkness, and over such rough grounds, without causing any sound. Bob found that he had almost to get down on his hands and knees and creep, in order to accomplish it. But his chum had not forgotten that he was new to this sort of business, and hence he gave Bob plenty of time.
Then Bob in turn began sniffing, and Frank knew that now he, too, had caught the trail-odor, which was constantly becoming stronger. Thus they were positive that while they moved forward they must be gradually drawing nearer the source of the smoke.
Another tug came at Frank's sleeve, at which signal he bent his head low so that his chum might say what he wanted in his ear.
"Sounds like voices!" whispered the excited Kentucky lad.
Frank gave a little affirmative grunt.
"Rustlers, maybe?" Bob went on.
The other made a low sound that somehow Bob seemed to interpret as meaning a negative to his question.
"Then prospectors—Lopez and his bunch?"
"Uh!" Frank replied; and then himself lowering his lips to the ear of Bob he went on: "What's the matter with Peg and his crowd? They might have got up here ahead of us. Quiet now!"
Bob did not attempt to say another word. He had new food for thought. Yes, to be sure, Peg and his two cowboy guides had had plenty of time to climb that far up the side of Thunder Mountain. If they had taken daylight for the task of course they avoided the danger of getting lost, such as had overtaken the saddle boys. And if the nerve of Spanish Joe and Nick Jennings continued to hold out, when strange things began to happen, the boastful tenderfoot from the East stood a chance of making a discovery.
As the two crept closer, on hands and knees, they could hear the murmur of voices grow louder, even though the speakers were evidently talking in low tones. While the experience was altogether new to Bob, he enjoyed it immensely. Why, after all, it was not so very hard to place his hands and knees in such fashion that he felt able to move along almost as silently as a snake might have done.
Now he was even able to locate the spot from which the murmur of voices came. Yes, and when he looked closer he saw a tiny spark that glowed regularly, just as a firefly might sparkle every ten seconds or so.
Bob solved that little mystery easily. Of course it was Spanish Joe, smoking one of the little cigarettes which he was so frequently rolling between his fingers.
To be sure, the odor of tobacco smoke mingled with that of burning wood. And if Spanish Joe, why not the other cowboy who was in bad repute among the ranches; yes, and Peg himself?
Bob began to wonder what the programme of his chum might be. Surely they would not take the chances of crawling up much closer now. If discovered they would run the risk of being fired upon; and besides, there was no necessity for such rashness.
Then Bob discovered that when the wind veered a little, as it seemed to be doing right along, he could actually catch what was being said.
Peg was talking at the time, and grumbling after his usual manner about something or other.
"Ten to one the fellow's gone and deserted us, Nick!" he remarked, suspicion in every word.
Apparently the lounging cowboy did not share in his opinion, for he laughed in a careless way as he drawled out:
"Oh! I reckon not, Peg. Me and Joe has hit up the pace fur some years in company, and I knows him too well to b'lieve he'd break loose from a soft snap like this here one. Jest lie low, an' he'll be back. Let's hope Joe's found out somethin' wuth knowin'."
"But he's been gone nearly an hour now," complained Peg.
"What of that? It ain't the easiest thing gettin' around on this rocky ole mounting in the pitch dark, let me tell ye, Peg," Nick remarked; and by the way he seemed to puff between each few words, Bob understood that it must be Nick who was using the cigarette, and not Spanish Joe.
"Say, that's so," admitted Peg, as if a new idea had come to him. "Perhaps he's slipped, and fallen down into one of those holes you showed me when we were coming up!"
This also amused the cowboy, for he chuckled again.
"Too easy an end for Spanish Joe," he said, carelessly. "Born fur the rope, and he can't cheat his fate. Same thing's been said 'bout me. Don't bother me none, though, and sometimes it's a real comfort; 'specially when a landslide carries ye down the side of a mounting like a railroad train, like I had happen to me. Nawthin' ain't agoin' to hurt ye if so be yer end's got to come by the rope."
"A landslide! Do they often have that sort of thing out here?" asked Peg, showing some anxiety, as though he had read about such terrible happenings, and did not care to make a close acquaintance with one.
"Sure we does, every little while," remarked Nick, cheerfully. "Why, jest last year the hull side of a peak 'bout forty mile north of here broke away, and a Injun village was wiped out. Never did hear anything from a single critter after that slip bore down on 'em."
"It might happen here on Thunder Mountain, too, couldn't it, Nick?" pursued Peg, as if the subject, with all it pictured to his active mind, held his interest gripped in such a fashion that he could not shake himself free.
"Easiest thing goin', Peg. And let me tell ye, if it ever do happen here, thar's agoin' to be a slide to beat the band!" Nick asserted, positively.
"But what makes you say that, Nick?" demanded the boy.
"Oh! lots of people says the same thing," replied the other, as if carelessly.
"That a landslide is going to start things going on Thunder Mountain any time—is that what you mean?" Peg insisted on repeating.
"Any day, er night. Things have been lookin' that way for some time now. I reckon she's due with the next big cloud-burst that sails this way."
It was evident that, for some reason, Nick was trying to frighten his young employer. Perhaps he himself really wished to get away from the mountain with the bad name; and took this means of accomplishing his end without showing his hand. If that were true, then he was gaining his end, for Peg certainly gave evidence of increasing uneasiness.
"But why didn't you tell me all this before?" he demanded, indignantly.
"What was the use, boss? Ye was sot on comin' here, and ye made Joe and me a rattlin' good offer. 'Sides, it didn't matter much to me. I had my life insured. A rope might have skeered me; but say, I don't keer that for landslips," and Nick snapped his fingers contemptuously.
But Frank, who knew the sly cow puncher so well, believed that more or less of his indifference was assumed.
"Well, I do!" declared Peg, with emphasis; "and if I'd only known about that sort of thing before, blessed if I'd a come. I've heard what happens when the side of a mountain tears away, and how everything in the path goes along. They showed me the bare wall where one broke loose up in Colorado. Say, it was the worst sight ever. You'll have to excuse me from nosing around here another day, if that sort of thing is hanging over this place. Me for the ranch on the jump. Get that, Nick?"
"Oh! now, what's the use botherin'? Chances are three to one they ain't agoin' to be any sech upsets as that yet awhile," the cowboy said.
"Only three to one!" burst out Peg. "All right, you can stick it out if you want, and I'll pay you all I agreed; but just you understand, Nick Jennings, when to-morrow comes, I want you to get me down on the prairie, where I can make a blue streak for the X-bar-X ranch house."
"But ye sed as how ye was detarmined to find out what made them roarin' n'ises, up here on old Thunder Mountain!" protested the guide, although he evidently expressed himself in this way only to further arouse the obstinate boy.
"I've changed my plans, that's all," Peg announced. "Any fellow can do that. It's always the privilege of a gentleman to alter his mind. I'd like to crow over Frank Haywood and that greenhorn chum of his mighty well; but I ain't going to run the chance of being carried down in a landslip just for that. Huh! I guess not! What I said, stands, Nick. And I hope the old slide comes while those two chaps are on the mountain; yes, and gives them a dandy free ride, to boot!"
"Oh! jest as ye say, Peg! I'm willin' to do anythin' to please ye. But p'raps we ain't goin' to git off so easy arter all," remarked Nick, suggestively.
"Now, what do you mean by hinting in that way? And I've noticed you twisting your neck to look up at the sky more'n a few times. Think it's going to rain, do you?" demanded Peg.
"Don'tthinknawthin' 'bout it; Iknowit be." And, Nick added, with emphasis, "I reckons as how it'll be jest ascreamerwhen she comes."
"A storm, you mean?"
"A howler. Allers does when the wind backs up that way into the sou'east. 'Sides, if so be ye air still sot on findin' out what makes that thunder up this ways, p'raps ye'll have the chanct to look into the same afore long, Peg."
"Oh! was that what I felt just now?" cried the boy, scrambling to his knees. "It seemed to me the old mountain was trembling just like I did once, when I had the ague. And Nick, I believe you're more'n half right, because I sure heard a low grumble just then, like far-away thunder. I wish I hadn't been such a fool as to come up here. Never get me doing such a silly thing again as long as I live. Listen! It's coming again, Nick, and louder than before. Don't you feel how the ground shivers? Perhaps there's going to be a terrible landslip right now! Do you think so, Nick?"
Frank and Bob, crouching close by, had also felt that quiver under them. It gave the saddle boys a queer feeling. When the solid earth moves it always affects human kind and animals in a way to induce fear; because of the confidence they put in the stability of the ground.
And then there arose gradually but with increasing force a deep terrible rumble.
Thunder Mountain was speaking!
"Oh! what shall we do, Nick?" cried Peg.
His voice was now quivering with fear. Evidently whatever little courage the fellow possessed, or the grit which had caused him to start upon this mission of attempting to discover the cause of the mystery connected with Thunder Mountain, had suddenly disappeared.
"Nawthin' 'cept stick it out, I reckons," replied Nick Jennings.
The superstitious cowboy was more or less anxious, himself. Frank, eagerly listening, could tell this from the way in which the fellow spoke. But Nick did not mean to fall into a panic. To try and rush down the precipitous side of that mountain in the dark would be madness. And with all his faults Nick was at least smart enough to understand what it meant by "jumping from the frying pan into the fire."
Another roar, louder than any that had yet broken forth, interrupted the excited conversation between the son of the mining millionaire and his guide. The whole mountain quivered. Bob himself was much impressed, and began to wonder more than ever what it could mean.
The noise died away, just as thunder generally does, growing fainter, until silence once more brooded over that wonderful mountain. Then again the two crouching lads caught the complaining voice of Peg. Bully that he was under ordinary conditions, he now showed his true colors. That awful sound, coming from the heart of the rocky mountain, as it seemed, had terrified Peg.
But Frank was not surprised, for he had all along believed that a fellow who could lift his hand to strike a small girl must be a coward at heart, no matter how much he might bluster and brag.
"This is terrible, Nick!" exclaimed Peg. "Can't you think of some way we might get out of this? Oh! I'd give a thousand dollars right now if only I was safe down on the plains again! What a fool I was to come here!"
"Well," drawled Nick, possibly with a touch of real envy in his voice, "I'd like right smart to 'arn that thousand, sure I would, Peg. But hang me if I kin see how it's agoin' to be done. We can't slide down; walkin's a risky business, and likely to take hours; an' right now I don't feel any wings asproutin' out of my shoulders, even if you do."
"Oh stop joking, Nick, and talk sense," complained Peg. "We've just got to do something. Why, the old mountain might take a notion to slide, and carry us along with it."
"I sure hopes not, at least right now," replied Nick, uneasily. "But I do reckons as how we're agoin' to git that storm afore mornin'."
"But see here, Nick," Peg went on, anxiously; "didn't you notice anything when you were leading me up here like a lamb to the slaughter? I mean, you ought to have seen whether this side of the old mountain was more likely to drop off than any other."
"Ye never kin tell nawthin' about such things," returned the cowboy. "Reckons all we kin do is to root around, an' see if we might find some sorter cave, where we'd be safe from the rain, if so be she comes arter a while."
"A cave!" echoed the other, as though startled. "What under the sun do we want to get inside the mountain for? Don't you understand that all that noise is comingoutof this old thing? I tell you, I believe it is a volcano, just as they told me, and perhaps she's going to break loose this very night!"
"Hey! what ye a sayin' that for?" demanded Nick. "Supposin' she is what ye tell, that ain't any reason the explosion's got to come this particular night, is it? She's kept on a growling for a hundred year now, an' nawthin's happened. Reckons it ain't agoin' to come off jest acause we pilgrims happens to be up here."
"But you said we ought to find a cave, and go in, Nick," continued the youth. "Suppose we do, and the sulphur fumes suffocate us? They must be just awful inside the mountain. This is a nice pickle for me to get into! If I stay out here I'm in danger of being drowned, or swept away by a landslide; if I go inside there's all the chance in the world that I'll be soaking in poisonous sulphur gas till I keel over. I'm up against it good and hard."
"We're all in the same boat, remember, Peg," declared the cowboy.
"But you knew more about this thing than I did, Nick. Why'd you let me come? It was all a fool business, and you're most to blame," protested Peg.
"Aw! let up on that kind of talk, will ye?" growled the cowboy, who was himself losing his respect for his employer, owing to the presence of those things which he did not understand, and the nearness of which aroused his own fears.
"I will, Nick; only get me out of this hole safe and sound, and I give you my word I'll pay you that thousand dollars. But where do you suppose Joe can be all this time? Has he run away, or dropped over into one of those pits we saw on the way up here? I wish he'd show up. Three would be better than two; and perhaps Joe might have a plan for us to get out of this."
Again did the low grumbling sound begin again, and silenced the conversation between Peg Grant and his cowboy guide, every word of which had come distinctly to the ears of the crouching saddle boys near by.
The rumble grew rapidly in volume, until once more the whole great mountain seemed to tremble. Bob was shivering partly from the excitement, and because he felt a touch of alarm.
But he could not help noticing the actions of his chum. When the thunderous roar was about at its height Frank had thrown himself flat on the ground. Bob could not see what he was doing, but his groping hand came in contact with the head of his comrade; and he discovered that it rested on the ground, with one ear pressed to the rock.
Frank was listening!
He knew how the ground carried sounds more distinctly than the air, and evidently he hoped to discover something concerning the thunder by this method of wireless telegraphy.
Then, as the volume of sound gradually decreased, just as a lion's roar dies away, Bob discovered that Peg and Nick were undoubtedly moving off. He supposed that Nick had made up his mind to hunt for an outcropping ledge, or some friendly opening, where he could be sheltered from the storm; and as Peg dared not stay alone, he was compelled to accompany his guide. The complaining voice of the rich man's son could be heard for a minute or so. Then even that ceased.
"They're gone, Frank!" exclaimed Bob.
"Yes, I know it," replied the other, as he arose from his position flat on the rocks. "And Peg is badly rattled, too. Say, I always told you he lacked real grit, and this proves it. He's scared at that noise. Think of him wanting to fly down to the plain! I reckon he's had about all of the exploring he wants. It's 'take me back to my daddy!' now with Peg."
"Well," remarked Bob, with a sigh, "I don't blame him so very much, Frank. I tell you what, that noise is enough to give anybody fits. I'm all of a tremble myself, and I'm honest enough to admit it."
"That's all right, Bob," replied his chum, quickly; "but are you ready to give the game up here and now?"
"Who, me?" answered the Kentucky boy, instantly; "well, I should say not—not by a long sight! No matter what comes, I'm ready to stick it out on this line if it takes all summer!"
"Just what I thought," chuckled Frank. "That's what makes all the difference between a brave fellow and a coward. Why, to tell you the truth, Bob, I'm shaking all over right now myself; but it isn't with fear. I'm excited, curious, and worked up; so are you. When you say you don't want to back out it tells the story that you're not afraid."
"But it wouldn't make any difference, Frank, seeing that we couldn't get away from here, even if we wanted to just now," remarked Bob.
"That's so," returned his chum; "just as Nick said; we're here, and we've just got to stick it out, no matter what comes."
"But do you take any stock in what Peg said about an avalanche?" asked Bob.
"Mighty little," Frank replied. "This mountain is made up mostly of solid rock. That's what makes lots of people believe in the volcano idea. A slide would be hard to start here, and it just couldn't carry much along with It. Where mountains have sides made up of earth and loose rocks, that happens sometimes."
"I'm glad to hear that," remarked the other. "But there comes another shake. Whew! feel how she trembles, Frank! Whatever sort of power can it be that makes this noise and shivering sensation?"
Frank waited until the convulsion had passed before replying.
"I've got a strong suspicion, Bob," He said, finally; "and it's something that came into my mind sincefeelingthe sound, for that's the only way I can express it. Now, what does it make you think of, most of all?"
"I did think it was thunder," declared Bob; "but now it seems to me the only thing I can compare it to is the beating of the terrible billows against the coast away up in Maine, when a fierce northeast storm is blowing. They seemed to make the rocks quiver just as this does now."
If Frank had intended to reply to this remark he was prevented by something unexpected that happened just then. This time it was not the furious roar of the unknown force within the mountain that disturbed him; but a cry that rang out shrilly.
"Help! Help!"
Bob clutched his companion's arm.
"Something has happened to Peg!" he exclaimed. "Perhaps the guide has thrown him over, and he's lost, and scared nearly to death!"
But Frank was more accustomed to reading voices in the open than was his chum.
"No, you're wrong there!" he cried, "that's Spanish Joe yelping; and he must be in a bad hole to call for his companions. Come on, Bob, we've just got to see what we can do to help him. Rascal that he is, he's human. Follow me!"
"Where can he be, Frank?" cried Bob, after they had been climbing for several minutes up the side of the rough mountain, almost groping their way, such was the darkness around them.
"Listen!"
"Help! Nick, this way, quick, or I'll go under!" came a shrill shout, only a little way above them.
They started for the spot; but before they had taken half a dozen steps once more the thunderous sound was heard; and under them the mountain quivered. As the boys were not more than human, it was only natural that they should halt until the convulsion had passed. Bob could not help clutching a spur of rock as though he feared that something dreadful was about to happen.
As the roaring noise began to die out the boys caught the cries of Spanish Joe once again. He seemed to be nearly frantic with fear, and was calling upon his cowboy crony not to forsake him in his extremity.
"It's going to tumble on me the next shake! Hurry, Nick, or I'm a goner!" they heard him pleading.
"Whatever can have happened to him?" asked Bob, awed by the exciting incidents by which they seemed to be surrounded.
"I reckon he's caught in some sort of trap, judging from his talk," Frank sent back over his shoulder; for both of them were climbing upward as rapidly as the conditions allowed.
It was no wonderful feat for Frank to make straight for the spot where the loud voice came from. He had located it; and even when Joe ceased calling for a minute or two, Frank was able to continue right on.
Apparently the cowman had heard some sound that told him of their coming. That accounted for his silence, since he was listening eagerly. And of course he fully expected that it must be Nick Jennings hastening to his assistance, perhaps with Peg at his heels. At least his words would indicate as much, when he cried again.
"Hurry, boys! There ain't any too much time. This way, right straight ahead! Oh! I'm in a hole, I tell ye. Ye ain't stopping, are ye? Come on! come on!"
They were now close to where the speaker must be located. Frank was already straining his eyes to make out his figure, so as to get some idea as to the nature of the new task that confronted them.
He presently could make out some object that squirmed and tugged between groans.
Then he knew that his first guess was probably correct. Spanish Joe, in making his way along over the rocks, had in some way managed to catch his foot in a crack, and was unable to get it out again. Perhaps the more he struggled the firmer it became fastened. And, considering the surroundings, his fright could hardly be wondered at.
So Frank crept up alongside the prisoner of the rock.
"It's my leg, Nick," cried the man, eagerly. "I can't get it loose and I've twisted and pulled till it's near jerked out of the socket. See if ye can't do somethin'. Every time she shakes, that rock up there just starts to drop down on me! If it comes I'll be smashed."
Frank knew Spanish Joe. The man from across the Rio Grande had worked on the Circle Ranch for many months, until he was discharged after being caught in the suspicious business of conveying information to the cattle rustlers.
"Wait 'till I strike a match, so I can see what things look like," Frank said.
And as the match suddenly flared up the dark-faced Spanish-American stared with astonishment into the countenance of the one who had come in answer to his frantic calls for assistance.
"You, Senor Frank?" he exclaimed.
"Sure," replied the rancher's son, as he bent over to examine the way in which the prisoner's foot had become caught.
Although the match only shone for a few seconds, Frank's quick eyes had sized up the situation.
"How is it, Senor Frank; can you get me out,camerado?" asked Joe, with a quiver in his voice.
Something of a desperado the man might be under ordinary conditions; but just then, when facing death, he proved very tame indeed.
"I reckon I can, Joe, if that tottering rock up there only holds off long enough. Let's hope it will. Now, do just what I tell you; and when I say pull, again, get busy for all you're worth!"
While Frank was talking he had been manipulating the foot of the Mexican, who had worked so long on American ranches that he had lost much of his national ways, though retaining a few of the characteristics of dress that always distinguish his kind.
Frank himself was not wasting time. He did not like the looks of that over-hanging rock any too well. It seemed to be about ready to crash down, and when it did come the result would be disastrous to anything human caught underneath; for it surely weighed many tons.
"Now, draw easily at first, and then increase gradually," Frank said. "I'll hold onto the foot, and keep it in this position. I think that's the way it first slipped into the crack!"
Spanish Joe eagerly obeyed. He groaned several times as he felt his leg hurt, but desperation lent him new determination; for if this attempt failed, as others had done, he believed that he was doomed.
Suddenly the foot came free. Joe fell over on the ground, but his last groan turned into a cry of delight. It was almost comical to see how quickly he rolled over several times, so as to get away from the danger zone.
Frank, turning, clutched his companion, and also drew him back. It was none too soon, it seemed. As if the release of Spanish Joe might have been the signal for the groaning mountain to once again take up its strange action, they felt the quiver with which all the performances. seemed to begin. Then the grumble commenced, rapidly advancing into a fearful stage, until Bob could feel himself trembling violently because the rocks under him were moving.
"There she comes!" cried Frank.
His words were drowned in a deafening crash close by. Had Peg Grant been there he must have believed that the top of the mountain had blown off, and that fire and boiling lava would immediately begin to pour down the sides. But Bob had not forgotten about that swaying rock. And he understood that it had fallen with a crash just at the spot where the three of them stood a minute before.
"What a narrow escape!" exclaimed Frank, after the clamor had in some measure died away again.
"Oh! I should say it was," echoed Bob, feeling quite weak as he realized what must have happened to them had they not gotten away in time.
"How about your leg, Joe; can you walk?" asked Frank, turning to the cowman, who was scrambling to his feet close by.
"Seems like I can, Senor Frank. But it was a close call for Spanish Joe. Only for you coming, where would I be right now? Let us get away from here!" exclaimed the man, limping around as he tried his crippled limb.
"You are free to go, if you want, Joe," remarked Frank; "but Bob and myself mean to stick it out. We came here to learn the cause of all this racket, and we'll do it, or know the reason why."
"Excuse me,companero, I know when I have had enough. This mountain is surely bewitched. There must be an evil spirit living inside. Do I not know it? And even the door is guarded by demons that spring at a man and tear him. My clothes, once so handsome, Senors, are torn into tatters, just because Joe, he was fool enough to step into that black opening above!"
Frank started as he heard the Mexican say this. It seemed to him that possibly here was a clue worth following up.
"Tell us what you mean, Joe," he asked, quickly. "What black opening did you try to enter; and what happened to you,amigo? We have done you a service, saved your life, perhaps. In return, tell us this."
"It is little enough, Senor Frank. Up above, not more than seventy feet from here, lies a hole in the ground. I was looking for shelter from the storm, because Senor Peg wished it. I entered. Hardly had I taken ten steps than something flew at me. I think it was a demon, for it had sharp claws, and I thought I could smell brimstone and sulphur. Just then the mountain yawned, and what with the terrible noise, and having to fight off that unseen enemy, I climbed out of there fast, but with all my fine clothes ruined. That was why I came down the side of the mountain in such haste that I caught my foot. I thought that fury was chasing me. Nothing in this wide world could tempt Spanish Joe to go back there. The storm, it is a joke besides that terror of the darkness!"
If he expected to alarm Frank, the Mexican cowman mistook the character of the boy. Frank believed that the fellow's fears had made him imagine more than half of what he declared had happened to him.
"Well, we leave you here, then, Joe," the boy remarked, sturdily; "because we're going to find that cave, and see what lies inside it. If you want to come along, all right; if notadios!"
He turned and started to climb, Bob tagging at his heels. But Spanish Joe could not bring himself to accept the invitation. He looked after the disappearing figures of the two saddle boys, and shook his head.
"No, not for Joe," he muttered. "He knows when he has had enough. Money could not drive him to enter there again, and meet that unseen thing. Out here the danger can be understood, but Joe he takes off his hat to the young Senors; for grit they surely possess.Adios, Senor Frank; but I doubt much whether we ever meet again."
But staunch of heart, Frank was leading the way upward, determined to accept of the challenge which the cowboy's due seemed to throw at his feet.