look after him? Two of you if possible.”

“I—I. How I’d like to!” Ballard was near to tears. “But he’d want me to stay with the mill. It—it might be terribly important.”

“All right you other two!”

Little Bexter gulped. He turned first red then white. It was evident that he had never ridden in a plane.

“I’ll go,” Johnny said quietly. “Be glad to.” An airplane was nothing new to him.

“I—I’ll go,” little Bexter breathed. “Bal—Ballard,” he caught his breath sharply, “you—you tell my folks I might not come back nev—never.”

“Oh come now, sonny!” the aviator exclaimed. “It’s not half as bad as that. Tell his mother he’ll be home for breakfast. Hot cakes and molasses. Hey, son?” He gave Bexter an assuring slap on the back.

Two minutes later they were in the air, all of them but Ballard. Skimming along over the narrow meadow, they rose higher and higher until the whole beautiful panorama of the Blue Ridge—Big Black Mountain, Little Black, Pine Ridge, and all the rest, lay spread out beneath them.

Little Bexter drew in a long, deep, breath, then shouted in Johnny’s ear: “I never dreamed it could be like this. I—”

He broke off. A pair of keen, gray eyes, were studying his face. Malcomb MacQueen had apparently regained consciousness.

Johnny too saw those eyes and liked them. “Keen eyes,” he thought. “He knows a great deal. Hope I can get to be his friend.” Then again came that haunting question: “How could this man go down into a mysterious space beneath a grist mill and by setting some sort of machinery in motion, produce something very valuable out of nothing but air and water?

“Perhaps he will tell me,” he thought. “But at least, not now.” He saw those gray eyes close, whether in unconsciousness or sleep, he could not tell. Sleep under such unusual circumstances appeared impossible, but this, he realized was a remarkable man.

It seemed to Johnny that the time consumed in that journey was remarkably short. To his utter surprise, he found himself circling over the roofs and chimneys of a sizeable city. Next moment, with a speed that was startling, they were shooting downward for a landing.

“Qui—quick trip,” he said to the pilot a moment later.

“Been quicker if my new motor were complete!” was the mysterious pilot’s strange reply.

But here were officers, doctors, an ambulance, all ordered in advance by two-way airplane radio. The little gray haired man was lifted out tenderly, then whisked away.

“You making a new kind of motor?” Johnny asked the pilot when everyone had departed.

“Motor’s not as new as the fuel I’ll use,” was the reply.

“What kind of fuel?” Johnny ventured.

“You’d be surprised!” The pilot looked away. “More foot pounds of energy for its weight than any yet discovered. Go around the world in non-stop flight—perhaps.”

“Whew!” Johnny breathed.

“Say! I’m starved!” the pilot exclaimed. “Guess we’ve done all we can for your friend, at least for the present. Want something to eat, you boys?”

Did they? Little Bexter grinned from ear to ear.

Early next morning they found themselves once more standing beside the airplane. A boy about Johnny’s age had just arrived.

“I’m Donald Day, Malcomb MacQueen’s grandson,” he introduced himself. “I want to thank you for looking after my grandfather,” he said to Johnny and Bexter.

“How—how is he?” Little Bexter’s words stuck in his throat.

“He’s pretty badly busted up!” Donald Day wrinkled his brow. “But he’s tough. He’s always lived right. The doctors say he will pull through but it will take a long time. And during that time,” he squared his shoulders, “during that time I’m to carry on his work.” He jingled a bunch of keys.

“In—down there in that space beneath the mill?” Johnny breathed.

The other boy shot him a quick look. “Yes. Down there,” he replied quietly.

A hundred questions were pressing in Johnny’s mind demanding an answer. He asked none of them.

“All right boys,” said the pilot. “I promised to have this little fellow home for breakfast.” He touched Bexter’s shoulder. “So guess we better step on the gas.”

“Yes,” Johnny thought. “Same old gas. But what fuel could he have been speaking of yesterday? A fresh mystery. I’m sure going to solve that one too.”

Then, as the big man-made bird took to the air, he thought once more of his promise to the coach. “Told him I’d find him a real half-back,” he thought for the hundredth time. “Be strange if I found him right down here in the mountains. But then, of course I won’t. Oh well, I’ll have a day or two of fishing. After that I’ll go back on the hunt for a half-back. Pray for luck, that’s what I’ll do.”

CHAPTER III
WITH THE AID OF NICODEMUS

Anyone witnessing the return of little Bexter to his home that morning might well have supposed that he had made at least two non-stop flights round the world, instead of one short trip to Louisville.

“Oh! Bex! Y’er back!” his small brother exclaimed. “You bin way up in the air! You bin all the way to Louisville!”

“Yes, I reckon,” Bex’s eyes were on his mother. She said never a word. Her face was a mask. “All the same,” Ballard whispered, “she’s dabbing at her eyes when we don’t look.”

“It’s a great moment for Bex’s folks,” Johnny smiled a happy smile. “I’m glad we got him back safe. They’ll never forget.”

“Now you all just draw up chairs and take yourself some pancakes,” Bex’s mother invited.

“Sorgum!” Ballard whispered to Johnny. “Sorgum molasses on real buckwheat pancakes. Yum! Yum! You can’t beat ’em.”

Nor can you. Johnny Thompson and Donald Day found this out soon enough. This mountain cabin was small. The kitchen was the smallest of its three rooms, but shone upon by the good mountain woman’s gleaming face, and warmed by her glowing hospitality, it became for those four hungry boys the largest, most gorgeous room in all the world.

“Sorgum,” Ballard murmured blissfully a half hour later. “Sorgum molasses and buckwheat pancakes.”

“Take yourself another helping,” said Bex’s mother.

“I couldn’t,” Ballard’s eyes rolled as he patted his stomach. “And I got to be going. I came away from the mill just to bring Bex home. Now I must go back.”

The mill, Johnny thought with a start. Oh yes, that mysterious mill. Perhaps Donald Day will show me its secrets.

A glorious golden moon hung like a Japanese lantern over the jagged ridge that is Stone Mountain when Johnny on the evening of that same day wended his way toward Cousin Bill’s home.

Although Johnny travelled over a trail that, winding along the mountainside, went up and down like a roller coaster, he did not look down upon rocks and ridges but upon a broad and fertile field, level as a floor. There are many such farms to be found in the narrow valleys of the Cumberland. This particular farm belonged to Colonel Crider. The Colonel, Johnny had been told, was rich. Smart racing horses, sometimes taken to the Kentucky Derby, contentedly grazed in his rich pastures. He had a daughter. Just about sixteen years old, Johnny guessed she was. Johnny had seen her only once and that at a distance, yet even at that distance, there was something about the dancing rhythm of her