“That’s all right. I thought I’d like to see you off safely so I told the guard to call me.” He sat down and chatted with them until they had finished, then went to the “Lark” about which a sentry marched in perfect military fashion and very businesslike. He saluted the captain, seemed relieved at the sight of the travelers, and stood respectfully while the party prepared to leave.

“We owe you a great deal, Captain Seaman,” Mr. Austin declared holding out his hand.

“Glad we could do anything for you.”

The three climbed into their places, Jim at the controls, and in a moment the engine was roaring. Except for the camp lights, the night was pitch black but they all knew that the dawn would be breaking before very long. The travelers and the soldiers waved farewells, then the “Lark” gave a gay little hop, and raced into the air. She seemed to realize that she had a great deal to do before she came down again, so she set to work with a good will. Jim climbed her thirty thousand feet before he leveled out, set his course, and shot forward like a star through the blackness. Twice Bob called through the speaking tube to the passenger in the rear, and Mr. Austin assured them he was quite safe and comfortable.

“I find that by sitting low my hands come close to the bulb, my boy, so that I can signal you the instant I scent danger, and as long as I can catch an occasional glimpse of your heads I am assured that all is well up front,” he told them.

“Corking idea. Do you see that morning star? Isn’t she a beauty?”

“She certainly is magnificent, but she will not shine very much longer for I believe that I see a sign of light in the distance.” After that chat they flew in silence, then Bob set himself to studying, while Jim continued to keep to his task of piloting. It seemed to him that Captain Seaman’s suggestion to continue the trip without a break was a very sensible one, and as he considered the matter he thought that Panama, where they had intended to make a stop might have proved another unlucky spot for them. There was no doubt now that someone was making a strenuous effort to prevent them from reaching Cuzco, and whoever was organizing the movement against them would have given Belize small consideration.

An hour later daylight was well on its way and the morning was glorious. The sun rose like a brilliant ball of color which reflected in numberless dancing shades on the vast expanse of water that was so much greater in proportion than the bits of land it surrounded. The “Lark” was going at top speed and never did the boys see the world roll under them so swiftly. It hardly seemed possible that an airplane could fly so fast, but the miles were clicking off on the indicator and the wind screamed sharply as they cut through it. Austin wondered if anything would happen that would necessitate carrying them along by the force of the central power and then he recalled that Don Haurea had said that one of the stations was in South America. The “Lark” must even now be in touch with it and the boy wished he had remembered to ask exactly where it was located. Staring ahead toward the distant land to which he was going he thought again of those ancient Spaniards and he tried to visualize the years that had passed, if the intellect of those adventurers would have been as highly developed as their brute courage. Into his mind came the recollection of the bitterness in the voice of the dignified Don when he spoke of the Pizarros, then through it flashed a vague idea. He wondered if the Haureas were descendants of those Yncas. It made him gasp.

Almost immediately came the recollection of that day in Vermont when he and Bob had gone to the little island in Lake Champlain to find Corso and his young nephew. How they had found the boy garbed in the exquisite robes of royalty, and how they had listened as Yncicea had told them of the ancient race which had preserved itself through the centuries. The youngster looked every inch a prince as he made his explanation simply, the chest of precious jewels at his feet. As a token of appreciation the Flying Buddies had each received two very valuable emeralds beside the rings they wore on their fingers.

“What a blue-ribbon turnip I’ve been. Yncicea is Don Haurea’s son. Ynca—that’s part of the title of the children of The Sun. Great Scott, of course—they are descendants of the Yncas—the real ones. Well, gosh, I’m glad of it. It’ll take more than a bunch of ignoramuses to ride rough shod over them again. Gee, I wonder how many there are now; some tribe, I’ll bet—”