Within ten minutes the last of them had mounted the ladder and gained the open night. All about them the huts of the village showed blackly in the starlight. They soon perceived that they stood at some distance from the central stone building, and that their place of captivity had been underground as they had surmised.

But although they had escaped from their prison they were still in fearful danger. Even as they waited there, a tall form, that of a sentry, strode around the corner of the building. In two bounds “red-jacket” was on him. He must have been possessed of huge strength, for the fellow went down like a nine-pin with the interpreter on top of him. When the latter arose the sentry lay quite still.

“You ain’t killed him, have you?” asked the captain as the interpreter rejoined the group.

“He says that if he has, it’ll be blamed on us,” the captain translated to his companions when the interpreter had whispered his reply.

“That’s fine,” muttered Tom; “a good beginning I must say.”

But their guardian was motioning to them to follow him. He had replaced the grating and concealed the rope ladder in some brush and rocks that grew near by. As they silently crept after their guide down a street of huts, they were all conscious of choking heart-beats and pulses that throbbed with uncomfortable rapidity. The slightest false step might bring the whole village down on them.

In this way they reached the end of the street and saw before them something that made them choke with delight. It was the huge, bulking outline of the Wondership. There she stood, seemingly as safe and sound as when they had left her.

With a whispered word to the captain that he had done all he dared, their guide left them here and slipped off among the shadows.

“The game is in our own hands now,” whispered the captain as they crept forward. “Go as silent as cats and we’re all right.”

On tip-toe, hardly daring to draw breath, they crept on toward the Wondership. It was like carrying a lighted torch above a pit full of dynamite. At any instant an explosion that would prove fatal to them all was liable to happen.

And suddenly it did.

As ill-luck would have it, one of Chekla’s subjects, either for hygienic or other reasons, had chosen to sleep out of doors that night. Tom’s foot struck him in the ribs, and with a yell that might have been heard a mile off the man sprang to his feet. Shouting at the top of his voice, he made for the village.

“Wow-ow! Now the fat’s in the fire!” gasped the skipper aghast at this unforeseen calamity. “Jack, if you can’t git that craft inter the air in five seconds or less, we’re gone coons!”

They set off on a run for the craft. All attempt at secrecy was useless now. It was simply a race against time. From the aroused village came a perfect babel of yells and shouts. Lights flashed. Savage imprecations resounded. The whole place was astir like a disturbed bee-hive.

Into the machine they tumbled helter-skelter. Jack switched on one of the shaded lights, pulled a lever and the welcome chug-chug of the gas pump responded. The Wondership swayed and pitched.

“Let ‘er go!” shouted the captain as from the village a mass of yelling savages came rushing down on them.

“Hold on!” shouted the young commander of the flying auto. “Where’s Tom?”

“Great Scott! Ain’t he here?”

“No!”

“Good Lord!” groaned the captain. “It’s all off now!”

But out of the darkness came a shout. It was Tom.

“Hold on. I’ll be with you.”

Then came the sounds of a struggle and the next instant they heard the impact of a crunching blow, a yell of pain and a savage shout, “Take that!”

“That’s Tom in action,” shouted the captain. “Come on, Tom!”

There was a rush of feet and the boy came bounding out of the darkness.

“Got lost in the shuffle!” he gasped.

“That’s all right,” shouted Mr. Chadwick, grabbing him; “in with you, boy, quick!”

In tumbled Tom, half climbing and half-dragged. He lay on the floor in a panting heap, while Jack swiftly raised the panels. This time they worked, and they found out afterward that the temporary sticking that had proved so disastrous was caused by the expansion of the metal in the hot sun.

He was not an instant too soon. Hardly had the plates clanged together with a metallic clash before the savages were on them. Captain Sprowl opened a port in the “whaleback” superstructure and poured out a murderous fire on the Indians before he could be checked.

“Warm work!” he cried, pumping away at the mechanism of the rifle.

From without, came yells and screams. Spears, darts and stones crashed against the machine as if they would smash it to atoms. But in the midst of the turmoil the fugitives felt a sudden upward lurch. So sudden was it that they were all hurled into a heap. But they cared but little for that. The Wondership was going up, bearing them aloft to safety!

As she shot upward, her machinery whirring bravely above the yells and confusion below, Captain Sprowl turned to the others.

“A good Yankee cheer, boys!” he said.

In the deafening din that followed, the professor’s voice was heard ringing out as loudly as any of them. It was the professor, too, who cried out at the conclusion:

“Undt ein Tiger!”

But perhaps the cheers had been a little premature. It was getting toward dawn when it became apparent to all on board that the Wondership was not behaving properly. Her engines revolved more and more slowly. She began to make long swoops and dips.

“What in the world ails her?” demanded the captain.

“Don’t know,” rejoined Jack; “might be any one of a dozen things. We’ll have to go down to fix her.”

“But it’s dark. You can’t land in the tree tops,” expostulated Mr. Chadwick.

“I know that. I think I can manage to keep her going till daylight. If not, we must take our chances.”

Soon after, the first pale light of dawn dimmed the stars. Beneath them—they were heading due east—showed a river. By this time the craft was almost without motion, although, of course, there was no fear of her dropping, for her gas-bag supported her. Bu............