There was a stir of excitement in the group at this bold announcement. The professor was jarred out of his usual calm. Kyle’s eyes sparkled and Teddy felt a thrill go through his veins. Only Alam retained his impassivity.

“Allah is great!” he muttered. “The strongest man is weak against the decrees of fate.”

“Hadn’t you better think that over twice, Frank?” asked the professor mildly.

“I’m used to making quick decisions,” returned the captain. “If I weren’t I wouldn’t be alive to-day. As it is, I’ve been thinking it over all the time that Alam has been talking. It will fit right into our other plans, anyway. Where we’re taking so many risks, one more won’t make much difference. From all accounts, this City of Brass, if it exists at all, is in a mountainous region, probably this Hoggar Plateau that we’re going to. And you heard what Alam said about the emeralds in his story of the city. The two things are bound up together. Let’s include them in our general scheme. If we find them, all right. If we don’t, we won’t be any the worse off. What do you say, Amos? Of course, I don’t want to rush you off your feet. Sleep on it and let me know what you think in the morning.”

That the plan had its appeal to the professor was evident by the glow that came into his cheeks and the speculative look into his eyes. Despite his equable temperament and his placid exterior, he was not destitute of the spirit of adventure. His burning enthusiasm in the cause of science had carried him into many uncivilized countries where he had been in danger from savage beasts and still more savage men. Many times he had needed all his courage and presence of mind to extricate himself from perilous situations, and so far these had not failed him.

“I don’t know that there would be any objection to making that one of the goals of our trip,” said the professor, at last. “As you say, failure would not detract from the value of the other objects of our expedition, and if by any chance we should run across this mysterious city, the gain to the world’s knowledge would be enormous.”

“I should say so!” broke in the captain. “It would cast in the shade all the other discoveries you have ever made, important as they are. It would give you a permanent place in history. Then let’s consider it settled that we’ll make the attempt to find it.”

“Of course, there are Alam’s objections to be considered,” remarked the professor. “I had rather set my heart on having him come with us as guide. From what I’ve heard, he knows the desert like a book, and is one of the most trustworthy and dependable of the Arabs in this section. I think very likely we’d be able to obtain his services for all the other objects of the expedition, but he may refuse if he finds we’re including the City of Brass among them. You’ve heard what he’s had to say about that.”

“Suppose we let that rest for a moment,” suggested the captain. “Find out what he knows about the Cave of Emeralds. Has he any definite idea where it is located?”

The professor turned to Alam and conversed with him earnestly for a few minutes.

“He’s sure it’s somewhere in the Hoggar range,” the professor explained. “He knows that Teddy’s father believed himself to be within a day’s journey from it at the time the raid was made on the caravan. That’s about as far as his real knowledge goes.”

“That isn’t so bad,” rejoined the captain. “If he can lead us to the spot where the fight occurred, so that we’ll be within a day’s march of the cave, we’ll have a chance to scout around and find it.”

“Or better yet,” suggested the professor, “if we can find Teddy’s father and he still has the map with him, our task will be made that much easier.”

“Right you are,” acquiesced the captain. “I think perhaps we’d better not discuss the matter much further to-night. We’ve already got a good deal of information that we want to think over and digest before we go any further. But there is just one thing that I’m curious about.”

“Let’s have it,” replied the professor.

“It’s just this,” was the reply. “If Alam is afraid to go with us into that region for fear he may happen to see the City of Brass and so suffer death, how came it that he was ready to go with Mr. Allison into the same district?”

“That’s a fair question,” returned Professor Bruce. “I’ll ask him.”

He turned to the Arab and put the question. The reply took several minutes.

“Alam says,” stated the professor, “that he went as far as he did because he knew that up to that spot, with which he was perfectly familiar, there was no danger of coming upon the mysterious city. But he would not have gone much farther into the Hoggar range. He would either have made camp to await Mr. Allison’s return and let the other go on alone, or, at the very most, he would have followed him only on foot.”

“Why on foot?” asked the captain, with a puzzled expression. “Wouldn’t that be just as dangerous for him as though he had been on a camel?”

“Not by any means,” replied the professor, with the merest suspicion of a smile, which, out of courtesy to his guest, he suppressed instantly. “The threat of death for anyone who sees the City of Brass only applies to mounted men. All others are immune. What are the exact words, Alam?” he asked.

“He who from his camel’s back looks upon the City of Brass shall be smitten with death,” chanted the Arab. “He and his beast shall fall to the ground together and the vultures shall devour them.”

“You see,” said the professor. “These people can’t conceive of any one being in the desert except on a camel’s back. They take that for granted.”

“I see,” mused the captain, and into his face came an expression of relief. “I think that solves our problem. I guess there won’t be any difficulty in getting Alam to come along as our guide. Can you come and see us again to-morrow night, Alam?” he asked.

“I will come,” replied Alam sententiously, as he rose and prepared to depart.

“And you be sure to come around the first thing in the morning, won’t you, Teddy?” urged Kyle, as his new-found friend prepared to accompany Alam.

“You bet I will,” replied Teddy enthusiastically. “Perhaps,” he added with a grin, “you’ll see more of me than you want to.”

“No danger of that,” put in the captain genially. “From now on, we regard you as one of the family, and you’re going to be under our care until we restore you to your father or to some other of your people.”

“I can’t thank you enough for all your kindness,” said Teddy, his voice trembling a little, as he and Alam left the room and went out into the night.

“I admit, Frank,” remarked the professor, when they were left alone, “that you piqued my curiosity a little when you expressed such confidence that we could get Alam to go with us despite his superstitious fears. Just what was your idea?”

“Because if he sees the City of Brass at all, I don’t imagine it will be from a camel’s back,” replied the captain.

“From what, then?” asked the professor, in some surprise, while Kyle also looked puzzled.

“From the seat of an automobile,” replied the captain.

[Chapter 05 Maze: Help Kyle Escape]