Naturally, after the first greeting’s had been exchanged, Mr. Jesson’s principal anxiety was for his son Tom. Jack soon set his mind at rest on this subject.

“Tom and Ned Bangs are back on the other side of the woods, with the aero-auto,” he explained.

“Ah, then it has proved a success?” eagerly interjected Mr. Chadwick.

“It is even better than we hoped it would be,” rejoined Jack enthusiastically.

“I wouldn’t be scared to trust myself to that aerial wind-jammer for a voyage to China,” stoutly declared Captain Andrews. “I reckon if Wellman had had a craft like that he’d have crossed the Atlantic easy as shooting.”

“I don’t know but what you’re right,” said Jack; “but the thing to discuss now is how to get out of here. Dad, do you know much about this place?”

“Nothing, except that there is a floor above this. We were confined there the first day of our captivity. But the sheet iron roof used for drying hemp made it so insufferably hot that we would have died if they hadn’t moved us down here,” was the reply.

“Then, so far as you know, there is no way of getting out but by the door we entered?”

“That’s the only way, I guess. We had better make good our escape while those rascally hangers-on about the settlement are off hunting for the fellows who rang their alarm bell.”

Professor Chadwick, to whom Jack had given a hasty outline of the events of the night, moved toward the door as he spoke. But he had not taken more than two steps toward the head of the stairs when he stopped abruptly.

“Hark!” he exclaimed, standing stock still in an attitude of close attention.

The murmur of voices came toward the party. It didn’t take any of them long to surmise what had happened. The searching party was coming back. In a few moments their egress would be cut off and it would be impossible to escape without a fight, the outcome of which was doubtful.

In this emergency Captain Andrews acted quickly. Gas-gun in hand, he ran down the stairway, shouting to the others to “come on.”

They pressed close behind him, each with a grim determination to reach the doorway before the guardians of the plantation noticed that it was open.

But in this they were disappointed. Hardly had Captain Andrews reached the doorway before several forms blocked it. As the doughty sea captain sprang at the foremost of them, at least a dozen of the husky henchmen of Herrera leaped on him.

Before either he or Jack could use their gas-guns, Captain Andrews was borne to the ground, while on top of him were piled half a dozen of the returned search party.

“Back to the upper room,” ordered Jack, “I’m going to fire my gas-gun.”

The boy shouted this warning because he knew that in that narrow space the fumes of the stupefying gas were likely to prove as disastrous to the white men as to the brawny negroes. Professor Chadwick, who well knew the qualities of the gas, retreated with the others. As he did so. Jack saw a rifle aimed at him by one of the negroes who crowded the doorway.

In a moment he had the gas-gun at his shoulder. He pressed the trigger and one of the sleep-laden globules shot out. It struck the armed negro in the chest, and the fellow threw up his arms with a sharp exhalation of his breath. Then he fell, as if his legs had been pulled from under him.

The fellows who were piled on top of Captain Andrews released him and dashed toward their other foe. As they left him the skipper of the Sea King sprang to his feet and discharged his weapon. The air became impregnated with stifling fumes.

Through the reek the seaman struggled to Jack’s side, and before the dazed negroes could realize what had occurred the two whites were shoulder to shoulder on the stairway.

Almost simultaneously the contents of the gas spheres began to have their effect. Man after man of those who remained, for several had fled, staggered and fell, while Jack and the captain retreated up the stairway. They lost no time in reaching the door at the head of the stairs and shutting it to keep out the fumes. They were none too soon. The gas had already affected them, and their heads throbbed and their eyelids felt leaden.

In the corner of the room was a big earthen pitcher of water. The Professor threw the contents of this over his son and Captain Andrews, and though still heavy from the effects of the gas, the shock revived them wonderfully.

“What now?” asked the Professor, after Jack and Captain Andrews had “come back to life” a little.

“Wait till the fumes of the gas have evaporated through the open door downstairs, and then make a dash for freedom,” said Captain Andrews.

“How long will it be before the air is good to breathe?” inquired Mr. Jesson.

“About fifteen minutes,” said the Professor; “the gas is of a very volatile nature, and the fumes will soon clear off. It will be an hour or so at least, however, before the negroes recover.”

“I would suggest, then, that Jack gives us a more detailed account of what occurred after he left Lone Island,” said Mr. Jesson.

Falling in with this idea, they seated themselves about the lad, who at once plunged into the details of the narrative, which, as may be imagined, proved of engrossing interest to all who heard him.

He was interrupted several times by questions and requests for information concerning the operation of the aero-auto, and the relation of his story took longer than had been anticipated. However, even in their critical situation, no one wanted to miss a word of it.

“And so the three gems are safe?” said Professor Chadwick, with a sigh of relief, as the lad concluded.

“Yes. They are at this moment in the Flying Road Racer’s locker, in charge of Tom and Ned,” was the reply.

As Jack spoke they all, by mutual consent, rose and made for the door.

“I shall be glad to get to the air,” remarked Professor Chadwick.

“Yes; it is insufferably hot in here,” agreed Mr. Jesson. “I had not noticed the heat so much while Jack was talking; but now,—phew! It’s like a furnace.”

As he spoke. Jack flung the door open. The next instant he staggered back, the hot blood in his veins frozen with horror.

A rush of air, hot and arid as a blast from a coke oven, struck him in the face. A great puff of smoke followed.

The room below was a vast furnace of red flame. In falling, one of the negro’s lanterns had overturned and rolled against the bales of dried hemp. All the time they had been talking the fire had been waxing more and more furious.

By this time the lower part of the stairway was in flames, and, as Jack held the door open, a tongue of fire, sucked upward by the draft, shot hungrily toward him.

He slammed the door instantly. But the heat of the seething furnace below rendered the air almost unbreathable.

It looked as if, in the very moment of their triumph, the adventurers were doomed to death in the burning building. Trapped and helpless, for an instant they were deprived of words. Was this to be their appalling destiny, their fate,—to be roasted alive without a chance of escape?