disappearing within the tent after his excited exclamations, jack left two bewildered individuals staring at each other beside the camp fire.

“what in the world can he mean?” wondered bob, getting to his feet.

“he has heard something over the radio,” surmised mr. hampton. “from the way he dashed into the tent, in fact, i’d say he’s still listening in. come on, let’s investigate.”

hastening across the intervening space, they pushed aside the tent flap, finding the interior lighted by lantern, and discovered frank seated at the radio with the headpiece clamped to his ears and jack bending above him.

as they entered they heard frank speaking into the transmitter say:

“here he is, mr. ransome. just a minute.” pulling the headpiece from his ears, frank proffered it to mr. hampton, while getting to his feet.

“what’s going on? who have you?” questioned mr. hampton, still bewildered. but at the same time he accepted the proffered instrument, while jack thrust him into the camp chair vacated by frank.

“it’s the english trader we met at kisumu,” responded frank. “he’s calling for you. says he’s called every night for a week over the station at entebbe where he is now located. but he’ll explain. talk to him.”

pulling the transmitter toward him, mr. hampton obediently called “hello.”

then bob, unable longer to control his impatience, seized frank and pulled him outside.

“now tell me what’s going on,” he commanded. “i don’t want to speak in there for fear of disturbing mr. hampton. but what’s this all about?”

it had grown appreciably darker in the short interval since bob had entered the tent, for once the sun goes down in equatorial africa night comes on apace. but the light of the lantern fell through the opening upon frank who stood holding back the flap and listening to what mr. hampton was saying inside, and this light showed his eyes ablaze with excitement.

he turned to bob as if reluctant to discontinue trying to hear what the older man seated at the radio transmitter was saying. then he grinned at big bob’s exasperation.

“listen, old thing,” he said. “we’re in luck.”

“luck?”

“yes, of the biggest kind. the man on the other end of the line is none other than the englishman we met at kisumu.”

“well, what of it? why don’t you tell me what he said?” big bob’s exasperation at this teasing grew apace.

“he’s been calling every night for a week from entebbe in the hope that we would pick him up. but as you know we haven’t been using the radio much, and so we haven’t happened to hear him.”

“all right,” said bob, his patience thoroughly exhausted. “i heard that. now will you talk turkey?” and reaching out a big arm, he pulled frank against his chest and began to knuckle his head with his free hand in the familiar fashion known as administering the “dutch rub.”

“ouch. leggo, you big bully,” gasped frank. “will you talk straight?”

“uh-huh.”

bob released him. “now speak up,” he said belligerently, “or who knows what’ll happen to you?”

“he wants us to go with him to the mountains of the moon?”

“are you trying to—”

frank backed off, laughing, hands held up defensively in front of him.

“no, i’m not trying to kid anybody,” he said. “well, what’s this ‘mountains of the moon’ stuff, then?”

“not the moon in the sky, bob,” said frank. “but a mountainous district in the belgian conga constituting the very heart of africa.”

“oh.” bob was mollified, but still puzzled. “what for?”

“there are active volcanoes over there, and mr. ransome says they are reported by native rumors reaching entebbe to be in eruption. he’s going in and says he thought we might want to go along.”

bob felt his interest quickened. volcanoes in active eruption. that would be something like, a sight worth travelling hundreds of miles to see. “fine,” he cried enthusiastically. “what wonderful picture stuff.”

frank nodded. “that’s what i thought of the first thing, too.”

“but what is mr. ransome going in for?” asked bob.

“oh, i suppose these fellows who knock about the wilds like to take in the sights as well as we who don’t live here all the time.”

“maybe so,” agreed bob. then, as a new thought occurred to him, he asked: “how soon could we get to entebbe? and how much farther does this volcanic region lie?”

frank confessed ignorance regarding the answers to both questions.

“come on, let’s go back inside,” he said, “now that your curiosity is satisfied. you know as much about it now as i do. let’s see what mr. hampton has to say.”

the latter concluded his conversation with “that’s agreed then and we’ll start tomorrow,” as the boys re-entered the tent, and from jack who had remained at his father’s shoulder burst a loud “hurray.”

“are we going?” cried frank eagerly.

mr. hampton nodded, and jack shouted, “first thing in the morning.”

“fine,” cried bob. “i was about fed up with this district, anyway. not enough excitement.” mr. hampton looked grave.

“you’ll get enough of that where we’re going,” he said.

“anything beside volcanoes?” queried bob, struck by something in the older man’s tone.

“ransome said there was some unrest amongst the natives,” mr. hampton replied, after a pause. “he seems to believe some of the german officials driven out of east africa are at the bottom of it, although he said there was no evidence of any such thing. all the native reports, he said, laid the trouble-making at the door of a new medicine man who has appeared in the devastated areas and is known as ‘the prophet.’ i couldn’t, of course, gain a very comprehensive survey of the situation during our rather brief conversation. but i did find out that this medicine man has gathered considerable of a following about him.”

“won’t it be dangerous?” asked a voice from the doorway, and they turned to find niellsen standing there. so engrossed had all inside the tent been that they had failed to note his approach.

he put down his motion picture camera and pulling a camp chair toward him sank into it with a sigh of weariness.

“i gathered enough to understand a trip to some place which might become hot for us is under discussion,” he said. “what about it?”

mr. hampton explained, adding: “like you, i’m afraid it may be too dangerous to undertake. at least, that is,” he added hastily to forestall the remonstrances which all three boys looked prepared to make, “we can go part of the way. certainly, into the volcanic region. but whether we push on amongst the disturbed tribes where this medicine man, the prophet, is supposed to be operating will have to depend on circumstances.”

the faces of the three boys grew bright again. “oh, of course,” agreed jack, quickly.

“but what i can’t understand,” added bob, harking back to the question he had earlier propounded to frank, “is why this chap ransome is going in. does he have plenty of money and time to go running around like this? and why did he call us and ask us to go along? why has he been waiting at entebbe for a week, trying to get us, instead of setting out?”

mr. hampton knew more than he was prepared to state. had the boys but known, which they did not, they would have suspected as much from the fact that at kisumu he had been in closest conversation for more than an hour with ransome, the ostensible invalid trader, in a locked room at the club. but of that conference they were unaware. this much, however, he did state:

“i believe him to be a secret agent of the british government, fellows. and, although the mountains of the moon lie in belgian territory, yet great britain is vitally interested in anything which may tend to upset conditions amongst the natives. as to his reasons for wishing us to accompany him, it is possible that mr. ransome wants us to act as a cloak for him.”

“i see,” said frank. “you mean that if we go in to take motion picture records of events, he can go along as a member of the expedition without arousing suspicion as to his real status?”

“exactly,” said mr. hampton, nodding his head in approval.

“time to go to the celebration of chief ungaba,” spoke a voice at the tent flap as mr. hampton concluded.

all turned about hastily. as in the case of niellsen’s approach, they had been unaware of anyone present.

it was mabele, the interpreter who had been employed at kisumu. he stood in a respectful attitude, holding up the tent flap, but not venturing to enter the tent.

“all right, mabele,” said mr. hampton, shortly. “we’ll come at once.”

silently, the black dropped the flap and withdrew. after a moment, mr. hampton arose and crossing the tent lifted the flap and stared into the moonlit darkness. then he let it fall and turned around.

“he’s gone,” he said. “now i wonder how much he heard.”

“oh, i guess he just came at that minute,” said niellsen, easily. “anyway, what does it matter?” mr. hampton shook his head. “i don’t know as it matters at all,” he replied, thoughtfully. “but that fellow is a man of superior parts. he’s smart. i wonder—”

then he shook himself and smiled.

“no matter,” he said. “niellsen, there’s a bit of food in the ice box which we saved for you. eat it, and then let’s get under way for the village. we’ll have to stay a little while, in order not to hurt the chief’s feelings. but we’ll leave before the party becomes too boisterous, so that we can make an early start tomorrow. we have a good five days of travel ahead of us before we can reach entebbe.”