“How did this happen, Mr. Porter?” demanded Dr. Byrd sternly, yet with an unmistakable quaver in his voice.

“I—I don’t know, sir,” stammered the manual training instructor. “I thought I heard his voice among the others on the way home.”

The fact was, Mr. Porter thought no such thing. He was merely frightened lest he be held responsible if anything serious had happened to Kenyon while the boy was in his charge. He felt guilty. He knew that he ought to have called the roll to determine if all were present before starting back for the school.

“Did anybody see Hal or hear his voice on the way back?” called out the doctor addressing the crowd of boys now gathered closely around him. No one had.

“Maybe he’s gone into the dining-room,” suggested Mr. Porter in an unnatural tone.

“No, he didn’t do anything of the sort,” returned the doctor. “I’ve been sitting out here for ten minutes waiting for you. Not a boy has entered this building in that time.”

There was an uncomfortable silence for a few moments, and then the doctor continued:

“If anything has happened to that boy I’m going to find out who’s responsible.”

“He was working in the river some o’ the time and it’s over his head, lots of places,” piped one small boy in fearful accents.

“Oh, it’s impossible for him to have been drowned,” declared Mr. Porter. “I kept my eyes on the boys in the river all the time they were there.”

Dr. Byrd offered no reply to this assurance. He merely said:

“All you boys go in and get your supper; then go to bed early.”

“Can’t we go with you and hunt for Hal?” pleaded Charley Mason.

“No. I’m not going to run any risk of losing any more of you. Besides, you’ve done enough for one day. I know you’re all tired.”

“No we’re not,” responded several. The fact is, they were well tired from their afternoon’s work, but love for their lost schoolmate had a refreshing effect. But the master of the school would not yield and they were forced to do as he said.

By this time Mr. Frankland had appeared, and as the boys filed into the wash room to prepare for supper, he was informed of the situation that had caused such a commotion.

“We’ve got to go and look for that boy and stick to the hunt until we find him—dead or alive,” almost sobbed the doctor.

“Oh, it can’t be as bad as that,” reassured the hopeful Mr. Frankland. “Hal’s a pretty level-headed boy and will be showing up with an explanation before long. I haven’t known him to get into trouble yet, and nearly every other boy in the school has been in one sort of scrape or another.”

“I hope you’re right, Frankland, but I very much fear otherwise. I can’t conceive of an explanation of his disappearance unless some serious accident has befallen him. But you go and find Pepper and have him get the auto ready, Mr. Porter; and, Mr. Frankland, you get a couple of long-handled rakes and some lanterns. I’ll get my medical and surgical cases and we’ll be prepared for any emergency.”

Pepper was soon found and instructed. A few words of explanation served to put speed in his actions, and in fifteen minutes the large touring car was backed out of the garage.

No unnecessary delay was permitted by the doctor. The medical and surgical cases were put aboard and all climbed in. Mr. Frankland, with two rakes in hand, sat behind with Mr. Porter, who had charge of the lanterns, and Dr. Byrd took a seat in front with the chauffeur.

Pepperill Humphrey served as chauffeur as well as janitor at Lakefarm Institute. He was a wise old man, always ready with “home-remedy” advice and droll humor. He could tell “bad boys” what was going to become of them more forebodingly, some said, than could any other forecaster of human events.

He was peculiarly quiet on the present occasion. After receiving a twenty-word explanation from Mr. Frankland, he asked one or two questions and then said nothing more. His silence might have been construed variously. He was fond of Hal, as was everybody else at the school, and possibly he was stunned at the news received. But he was observed several times to nod his head vigorously and to mutter in a very positive manner.

The other members of the search party, however, were too much occupied with their own thoughts to ask for an explanation from the janitor-chauffeur. They rode along in silence for most of the way. The doctor had gained all the information that seemed obtainable. Mr. Porter, because of the criticism he had received, wished to draw as little attention to himself as possible, and Mr. Frankland appreciated the embarrassment of the situation.

There was a fairly good road from the school to the northern pass of the caÑon, including a bridge over Lake River near its junction with Flathead River, which ran through the caÑon, and along this they advanced close to the spot where the airship had struck. Here they stopped, and the search for Hal was started.

First they shouted his name again and again, permitting the echoes to die away after each shout; but no reply came. Then they lighted their lanterns, one for each, and started in pairs up and down the bank of the river.

Mr. Porter indicated the section of the stream along which Hal had conducted his hunt for Mr. Miles’ bag of souvenirs, and it was from a middle point in this section that search for the missing boy began. For a few hundred feet here the water was deep and comparatively quiet; but above this calmer stretch was a succession of falls so noisy as to make it necessary to shout in order to be heard.

The largest and noisiest of these falls was the lowest one. Dr. Byrd and Mr. Porter went upstream as far as this cataract, and stood a short time gazing into the water. There was little comfort in the feelings that possessed them as they gazed. The falling water glittered in the yellow moonlight, seeming to shine forth with a million ghost eyes, and in the noise of that tumbling flood every now and then they heard a strange sharp sound that seemed to pierce them through.

Mr. Porter took hold of the doctor’s sleeve and drew him away. They walked some distance down stream until their ordinary voices could be heard, and then Mr. Porter said:

“Let’s not begin by raking the river. If he’s drowned, we can’t do anything for him; but if he’s injured, he needs our aid.”

“Well, where would you suggest that we hunt first?” inquired the doctor.

“In the timber and thickets near the falls. He may have gone in there and got hurt.”

“All right. We’ll search every place you suggest before we rake the river.”

Mr. Frankland and Pepper were now observed coming up along the shore, and the doctor and Mr. Porter waited for them.

After the four were reunited, Mr. Frankland said:

“We’ve covered the ground pretty well down there. Everything’s open and fairly level. We measured the water with our rake, too, and it isn’t over a boy’s head any place, although it is swift as a millrace.”

“If he’s drowned, his body’s probably in this deeper part near the falls,” said Dr. Byrd. “We’re going up in the timber and hunt there first, and then come back here if we don’t find him.”

“It might be just possible that he waded over to the other side and was hunting along the steep base of old Flathead and fell in there,” suggested Mr. Frankland.

“We’ll hope not,” returned the doctor; “but we’ll follow that up after we’ve tried everything else.”

The timber they now proceeded to search consisted principally of spruce, pines and cottonwood growing on a slope that ascended with the bed of the stream. The soil was fairly good here, being comparatively free from small stones and gravel, but there were numerous large bowlders and rocky projections that the search-party had to climb over or around.

They spent an hour and a half, walking, crawling and climbing over this difficult ground, flashing their lanterns into every hole or depression, and stopping every now and then to call Hal’s name. At last, considerably disheartened, they returned to the bank of the river below the falls.

“Let’s go down to the rapids and work up,” suggested Mr. Porter. “He was working that way most of the time I think. I saw him down there and didn’t see him up here.”

This proposal was agreed upon, so they walked down stream two hundred yards from the largest and lowest fall and began to work up. Two of the men held the lanterns, while the others thrust the long-handled rakes into the water and felt along the bank.

They pushed the rakes out as far as they could and drew them in many times. On several occasions they were almost certain they had found the body of the missing boy, but their discovery proved to be only a log or a tangled mass of sticks and weeds. Finally they worked up to the lower waterfall and then moved away from the roaring noise to a distance where they could hear each other talk.

“The only thing that seems to be left to do is to go to the other side and rake the river bed over there,” remarked Mr. Frankland.

“Yes, and if he was drowned even on that side, it’ll be just our luck not to find him,” said Mr. Porter. “The body’s probably drifted into midstream and may be down past the rapids.”

“If we don’t find him to-night, we’ll come back again to-morrow and drag the river to its junction with Lake River,” the doctor announced determinedly.

“There’s something funny about them falls,” remarked Pepper, who had been strangely silent during the whole of the search thus far.

“What’s that?” inquired Mr. Porter, who was still nervous and easily drawn into almost any meaningless conversation.

“Don’t you hear it?” explained the chauffeur. “That noise every little bit. Sounds like a scream coming right out of the water.”

“Oh, that’s natural enough,” declared the manual training instructor. “It’s a twist or eddy sucking into some crevice in the rocks.”

“I don’t believe it,” insisted Pepper. “Many a time I’ve been here on Sunday afternoon and set here listenin’ to them falls, an’ never before heard that noise.”

“What do you think it is—a ghost?” inquired Mr. Porter with an uneasy laugh.

“No, sir,” replied the other indignantly. “But it’s something ’at ought to be looked into. We’re huntin’ for a missin’ boy, you know.”

“There is something strange in that sound,” put in Dr. Byrd at this point. “I wonder what it can be. Mr. Porter, your explanation doesn’t satisfy me.”

“Nor me either,” said Mr. Frankland.

Just then another and louder scream came seemingly right out of the tumbling flood, thrilling fearfully every member of the boy-hunting party. For a few moments everybody present stood as if frozen to the ground; then Dr. Byrd sprang forward exclaiming:

“Come on; we’ve got to find out what that means.”