In after days, Frank was to remember with thankfulness the of Wimba for his “baas” or master. But now he was embarrassed, and making light of the matter as possible without hurting the black’s feelings he hastened along by ’s side across the meadow toward the of tents which marked their encampment.  
Leaving Jack and Frank to the convalescent Bob with the tale of what had occurred under the council tree, while Wimba and Matse put their heads together and discussed the same event surrounded by the awe-stricken native bearers from whom Wimba, at Frank’s warning, was careful to the real explanation, let us consider how the three white boys came to be here in Central Africa.
 
For those of our readers who have not followed their adventures in other parts of the world as set in previous volumes of The Radio Boys Series a brief word or two of introduction is necessary. Jack Hampton was the only son of an internationally famous engineer and explorer, whose wife had died when Jack was only a youngster. Frank Merrick, too, was and made his home with Bob Temple, whose father was his . The Hampton and Temple country estates on the far end of Long Island, New York, adjoined each other. And the three boys, companions at preparatory school and now at Yale, were the closest of friends.
 
Supplied by wealthy parents with the means to gratify their scientific , all three boys from the beginning of the popularity of Radio had pushed their in that field. And upon the numerous adventures into which they had been in one way or another in South America, Alaska, their own land, and the Sahara Desert in Africa, they had found Radio time and again prove of the greatest service.
 
Now, as has been related in the previous chapters, it had again come to the to help them at a crisis in their affairs.
 
But how did they come to be again in Africa, where the previous year they had discovered in an unexplored mountain region in the southern Sahara a race of white men living in a high state of development and treasuring ancient records indicating continued existence of the race from the earliest period of the world’s history?
 
That is easily explained.
 
So widespread was the showered upon the Radio Boys, as they had become known, following their repeated exploits in out-of-the-way corners of the world that one of the great motion picture concerns of America had come to them some months with a fine offer. Would they accompany a cameraman into Central Africa to explore little known or unknown regions for the purpose of filming wild animals in their natural haunts and natives in the state? That was the proposition, and, needless to state, the motion picture concern it agreed to make acceptance worth the boys’ while.
 
Mr. Hampton was included in the offer. And upon his advice, coupled with that of Mr. Temple, the boys had yielded to their natural and had accepted.
 
“You boys have still some years of college ahead of you,” Mr. Temple had said. “It may be unwise to interrupt your college career, for such an expedition necessarily will be an interruption, as, , you will be a year or two in the wilds. Nevertheless, Central Africa cannot remain unexplored or unopened to civilization much longer. Here is a chance such as may never come your way again.
 
“Sometime, doubtless, Jack will want to become an engineer and follow in his father’s footsteps, and Frank and Bob will want to take charge of the export business, Frank’s father before he died and I, built up. But there is no hurry about those matters. In the meantime, here is a chance for the three of you to go on a big game hunting expedition with the strangest of weapons—a motion picture camera. And you will be well paid, to boot.
 
“Of course, the fame you fellows have piled up brought you this opportunity. Well, you deserve it. Three more rattle-brained with the ability always to fall on their feet I never saw.” He smiled at them affectionately. “So,” he concluded, “I consent to Bob and Frank going. And as Jack’s father already has consented for him and is, besides, to head the expedition, I cannot see but what that settles the matter.”
 
Here, then, they were. From Mombasa on the east coast they had made their way on the railroad to Nairobi. This small but important settlement, which was the center of Kenya Colony, marked their last touch with civilization.
 
bearers and guides, they had thence set out afoot into the Kikuyu country. Day had followed day without striking incident. The Kikuyus are a peaceful people, above the average of African intelligence, inhabiting a magnificent country in streams, uplands and forest. It is one of the most healthful and fertile of regions.
 
Although, despite their to the advance guards of white civilization, the boys had found the Kikuyus still living in primitive state, nevertheless they found them peaceful. Adventures had been few. Not only had they seldom been in any danger from the natives, but wild animals also had been scarce.
 
It was not until they came to Chief Ruku-Ru’s territory where Mr. Hampton had departed with Niellsen, the cameraman, for the dried-up bed of a river where were said to be in the habit of coming to dig for water, that the first real adventure befell them. That was the arrest and trial of Wimba, and his consequent release as related.
 
It was only by accident that the boys were on hand. Ordinarily they would have been with Mr. Hampton and Niellsen. But Bob’s to fever had kept them behind to provide him with company and attendance. Bob’s fever was not strong enough to cause Mr. Hampton any real anxiety, however, so, leaving the boys careful instructions regarding the medicines to be given their comrade, he had departed with Niellsen and a few bearers carrying camera, film box, etc.
 
With this digression, let us return to camp. The quick-falling African night was closing in and the boys were finishing preparations for the concert which they had promised to bring out of the air to the assembled villagers about the council tree.
 
Frank and Jack had just completed a complete of the talking machine which they planned to use and were dusting off the records of band music which they considered would provide the most acceptable concert for ears. Bob who was feeling improved was lolling on a camp cot, watching them.
 
“Hey, fellows,” he said suddenly, “has it occurred to you that some more curious and less fearful than the rest might climb up into the council tree? If one does, and if he finds the aerial or the loudspeaker which you there, good night. Even if he ran away from it, he might damage it first so that your concert would be a fizzle.”
 
Jack stopped work, a record in one hand, dusting cloth in the other.
 
“That’s right, Bob. Hadn’t thought of that.”
 
But Frank looked unconcerned.
 
“From what Wimba and Matse tell me,” he said, “Most Kikuyus wouldn’t dare to climb into that sacred tree. I had a hard time getting even those two to it with me last night and help locate our traps. And they’ve lived in Nairobi and come in contact with the whites and have lost some of their native . And now that we caused the voice of our mysterious spirit to from the tree today, I feel pretty sure there isn’t a Kikuyu whom you could pay to climb it.”
 
Jack looked relieved, but Bob was reluctant to his idea and needed further convincing.
 
“Just the same,” he said, “I believe we ought to send somebody over there to around for us and see that everything is all right before we pin our hopes on giving a concert. Why not send Matse?”
 
“All right, if you think it’s necessary,” replied Frank. “Let’s call him in.”
 
Putting aside the records he had been cleaning, he went to the door of the tent and, lifting the flap, his head out to utter the necessary call which would bring Matse from the bearer’s camp nearby.
 
But the call was not issued. Instead, Bob and Jack heard Frank utter a and then step swiftly out of the tent, letting the flap fall behind him.