Next day Dr. Byrd related an aeroplane story to the boys in the assembly room. It was the story of Mr. Johnson Miles, the aviator who lay on a bed in the “Hospital” striving to help mend his broken bones by thinking hopeful thoughts. It was a story of absorbing interest to the young Scouts and afforded material for much excited conversation for several days thereafter.

Mr. Miles had related his experiences in detail. He said that his home was in Indianapolis and that he had flown all the way from that city in his aeroplane. He had already spent several weeks among and over the mountains, his purpose being to visit the Rockies as a bird would visit them, and to collect specimens.

“I was on my way to Flathead Mountain when I fell almost at its base,” he told the doctor. “It was moonlight and I thought I would fly awhile, as it is really mighty pleasant to sail through the air with the moon and stars overhead. It’s like racing along a lonely road in an automobile and seeing a ghost behind every post.”

“You have an odd idea of enjoyment,” remarked the doctor.

“Oh, it’s thrilling,” declared the aviator. “The ghosts can’t catch you in an automobile, and you just cut right through them in the air.

“But I was forced to stay up longer than I wanted to. The country was so rough that I could find no place to land. Then I found my gasoline almost gone and I knew I must glide and take my chances. The engine began to jerk and sputter and gasp, warning me of immediate danger.

“That was a bad miscalculation I made regarding my gasoline. I thought I had enough to last me several hours. I had intended to fly only an hour or two by moonlight. I was right over the mountains when I discovered the condition of my gasoline, and you can imagine the state of mind it threw me into. All the ghosts I had cut through in the air hadn’t begun to chill me the way this did. Fifty thousand icicles stuck down my back wouldn’t have been a circumstance to this.

“It was so dark down on the earth, in spite of the moon, that I could hardly distinguish mountains from valleys. I was flying five hundred feet over the highest peaks, and began to glide as soon as I discovered my predicament.

“Presently I saw a large gulch that you call Mummy CaÑon right below me. So I banked and circled around without realizing that I was so near the mountain I was searching for. But when about fifty feet from the ground a couple of my stay wires broke and warped the left wing. I worked my ailerons in an endeavor to balance the machine, but it was no use. Down she flopped, and I leaped. I don’t know how I managed to get clear of the struts and the planes, but I did, and—well, it was mighty lucky you folks were near, or I’d have died a lonely death. Probably nobody would’ve come that way until I was food for the crows.”

“What became of your specimens?” inquired the doctor. “Didn’t you have any with you, or hadn’t you gathered any yet?”

“Oh, my, yes!” replied Miles. “I’d been in the mountains several weeks. Didn’t you find them?”

“No. Where did you drop them?”

“They were in a leather bag tied to one of the struts near my seat. It’s mighty funny you didn’t find them.”

“Maybe the bag was broken loose when the machine struck the ground, and was thrown some distance away,” suggested the doctor.

“That might be, but I should think one of all those boys would have found it when they went after the aeroplane.”

“Yes, I should think so, too, unless it fell into a hole or behind a big rock. Were the contents of the bag valuable?”

“I wouldn’t have taken one thousand dollars for them,” said the aviator sadly. “In fact, I regret their loss more than the wreck of the biplane.”

“We’ll make a thorough search for them,” assured the doctor as he left his patient.

This conversation took place shortly before noon. After dinner the boys were instructed to meet in the assembly room. There the doctor retold Mr. Miles’ story in detail and then said:

“I’m going to give you another half holiday, boys—”

“Hooray!” exclaimed Ferdinand Sharer in a loud whisper.

“Hold on, Ferdinand. Shut off your enthusiasm, for this isn’t going to be an occasion of play. You have a very serious duty to perform, and I want you to go about it seriously.”

“We will,” assured several of the boys.

“Yes, I know you intend to be serious,” said the owner of Lakefarm, with a wise shake of his iron-gray locks. “But I want you to be more than serious. I want you to use your wits, too, a little. A treasure has been lost and I want you to go in search of it; and if you don’t find it, I want you to furnish a clew as to what has become of it.”

Dr. Byrd’s Boy Scouts could no longer contain themselves. Most of them just had to give vent to their feelings with loud-whispered “hoorays!” or other characteristic expressions of glee.

“Remember, now,” insisted the master of the school just before he instructed the troop of Scouts to file out; “I want you to use your heads and do some good work. That bag of relics is valuable and must be found. If it isn’t lying on the ground near the place where the aeroplane struck, I want to know why. Mr. Porter will go with you.”

This was rather a large task to impose on any number of boys. To be sure, if the bag were lying near the spot in question, they ought to find it, or rather they should have discovered it already; but if it had mysteriously disappeared, how were thirty boys to conjure an explanation of the mystery?

Naturally this question, variously phrased, occurred to a number of the Scouts as they listened to the doctor’s latest words, but they were too young to ponder very deeply over the difficulty of any problem and soon dismissed this one from their minds.

“You may stay until dark if it takes that long to find it,” concluded Dr. Byrd. “Now, everybody go to the kitchen and get some sandwiches that you’ll find all ready. You’ll all be hungry before you get back.”

There was no need of further urging. The boys filed eagerly out of the room, hastened to their lockers and got their drab coats, drill hats, haversacks, and hike-sticks, and then went to the kitchen for their sandwiches. In twenty minutes they were on their way.

The course from the school to Mummy CaÑon is pretty and interesting. It follows the bed of the river most of the way. This stream, named Lake River by Dr. Byrd, varies from thirty to forty feet wide and carries considerable volume of water. It runs southward a mile and a half along the foothills, then turns westward after receiving the water of Flathead River from Mummy CaÑon. The rest of the way is up-hill, along the bank of the latter river or near it.

Mummy CaÑon is more than two miles long, its greatest width, near the center, being nearly half a mile. It is almost entirely hemmed in by mountains, there being a narrow pass at either end, north and south. Flathead River has its source, or sources, high up in the mountains, and dashes down in a series of noisy cascades and cataracts, making a graceful curve for a quarter of a mile along the base of Flathead Mountain, from there leaping down a very rocky course to and through the northern pass.

The young Scouts and Mr. Porter walked halfway through the caÑon before they reached the place where the aeroplane struck the earth. To the west arose Flathead Mountain, considerably lower than the other mountains bordering the caÑon. From the “forehead” of Flathead the mummy stood forth conspicuously. The bottom of the caÑon was strewn with bowlders of every size and description. On the east, exactly opposite Flathead, was a steep ascent so rocky as to permit of little vegetation save a pine or fir here and there growing from a crevice that seemed not to contain a trace of soil. High up on the ascent were poised several huge bowlders, and hence its name of Bowlder Mountain.

On a level and treeless spot several acres in extent between Flathead and Bowlder Mountain, the Boy Scouts and Mr. Porter began their search for the missing bag of specimens. Almost in the middle of the grassy plot, the sod had been torn and rooted up by the plunging machine, and it did not take the searchers long to decide that the object they sought was not there in the open.

“Well, what do you think of it, boys?” inquired Mr. Porter. “Remember, you’re to do all the work and furnish all the ideas. Who has an idea now?”

“I have,” announced Fes Sharer.

“All right. We’ll listen to Ferdinand first.”

“I think this is all a pipe dream of the airship man’s,” declared Fes, who was an extremely practical youth and always demanded evidence before he would believe anything. “I think he struck his head on a rock and hasn’t come to his senses yet.”

“Don’t you believe he had a bag of souvenirs?” inquired the instructor.

“Naw,” was the skeptical answer. “If he did, what became of it? It’d had to fall with the airship.”

“Yes, if it was tied to it,” conditioned Juan Del Mar.

“He says it was tied to the aeroplane,” reminded Mr. Porter.

“I think he’s dreaming,” insisted Fes. “If he had a bag of specimens with him, it wasn’t tied to the airship; or if it was, it broke loose or came untied while it was falling.”

“I think it came untied,” declared Pickles.

“What do the rest of you think?” inquired Mr. Porter.

As any thought on the subject must be largely a matter of guess, none of the boys besides Fes and Pickles were inclined to be very positive. All, however, were willing to accept Ferdinand’s explanation.

“Then it’s up to us to search the whole caÑon, or a good piece of it, around here,” declared Hal Kenyon.

Several others agreed with him, although a few of the more doubtful said they were just as ready to believe that the bag had been dropped outside of the caÑon.

“I bet it dropped right on the peak of Bowlder Mountain, or maybe on the top of Flathead,” one boy even declared.

It was now half past three o’clock, and as it would be dark early in the caÑon, the boys set to work diligently to cover as much ground as possible before daylight failed them. They divided up the territory, and each boy tried to confine his search to his assignment.

Hal had a stretch of several acres along the creek at the base of Flathead Mountain. In the course of an hour he went over it thoroughly, without finding the treasured bag and hearing no joyful cry of discovery from any of the other boys. Meanwhile it occurred to him that the bag might just as well have fallen into the river as any other place, and he determined to search in the water also.

This required a good deal of time. In some of the wider places the stream was shallow and he could see the stony or pebbly bottom. But in other places he found it necessary to exercise greater care. He took off his shoes and stockings and rolled up his trousers as high as he could; then he waded in and began a thorough search. Where the water was too deep for wading, he used his hike-stick to feel the bottom.

In the meantime other boys, to whom had been assigned other sections along the creek, observed what Hal was doing and followed his example. The search went along quietly, for all of the Scouts were too widely separated to engage in much conversation. When they became hungry, they ate their sandwiches and drank spring water and then returned to their work.

But at last it grew too dark for further hunting among the rocks, trees and bushes, or even in the open, and Mr. Porter called them together. The search seemed to have been in vain. The leather bag of the aviator was still lost, and nobody believed that it would ever be found, unless by accident.

“Well, we did our best anyway,” said Byron Bowler.

“You bet we did, Bun,” agreed Pickles, following the general boy habit of shortening Byron to “Bun.” “I’m tired.”

“So’m I,” declared several others.

“We’ll start home now,” announced Mr. Porter. “Everybody here?”

“All here,” replied one of the boys, assuming that everybody had answered Mr. Porter’s whistle.

The walk back to Lakefarm was quiet. The boys were all tired and found little of interest to discuss in their fruitless search. On the campus they were met by Dr. Byrd and Mr. Frankland, who inquired as to their success.

“Nothing doing,” replied Roy Hendricks. “We searched pretty near the whole caÑon and come back with empty hands.”

“Yes, and we searched the river, too,” repeated Bun. “Hal Kenyon started that. We waded through the shallow places.”

“Where is Hal?” inquired Pickles. “I ain’t seen him all the way back.”

There was no answer.

“What’s that?” inquired the doctor. “Kenyon missing? Hal, step forward.”

There was no answer and no stepping forward. All was excitement soon. Hal’s name was called, then shouted by a dozen throats, and still no reply.

Young Kenyon had disappeared as mysteriously as had the bag of specimens of the injured aviator.