FAR into the distance, as far as the eye could see, stretched the boundless water of Lake Victoria, resembling nothing so much as a vast ocean. Even at the far-away horizon there was no trace of land.

“Wow!” gasped Bob, who was taken totally by surprise. “You’re not kidding us about this being a lake, are you?”

Mr. Holton laughed.

“We thought it would get you,” he said. “Boys, you’re looking at one of the largest lakes in the entire world. Covers an area of nearly twenty seven thousand square miles, and is over two hundred and fifty miles long.”

“Biggest I’ve ever seen,” remarked Joe. “And right here in the heart of Africa.”

He had brought a motion-picture camera and now removed it to roll off a fair amount of film.

“What’s that away over there?” inquired Bob wonderingly, pointing to a dark cloud that hovered near the surface of the water.

The others gazed intently for several moments. Then, when the dark mass was slightly nearer, Mr. Lewis uttered an exclamation.

“If I’m not mistaken, that cloud isn’t a cloud,” he said, removing his binoculars from their case.

“Then—what is it?” demanded Joe.

A moment later his father confirmed his own opinion.

“Just as I thought,” Mr. Lewis said, peering out through his powerful glasses. “That isn’t a cloud at all. It is a big mass of insects.”

“Insects?” repeated Bob. “You mean that what looks like a cloud is nothing but a lot of insects flying together?”

Mr. Lewis nodded and passed the binoculars to Bob.

It required but a second for the youth to observe that his chum’s father was right.

“Man alive!” he murmured. “There must be millions of those little creatures. I sure wouldn’t want to get in that swarm.”

“I shouldn’t imagine it would be very pleasant,” said Mr. Holton dryly.

They spent several more minutes in walking along the banks of the lake and then turned back into the town.

“What will we do now?” asked Joe, as they walked along the main street.

“We’re going to take an automobile,” answered his father.

“Oh, come, Dad,” Joe broke out. “What are you talking about?”

“Just what I said,” answered Mr. Lewis. “Howard and I engaged an automobile. We’ll drive to a town called Mbarara—that’s a good day’s journey to the southwest. From there we’ll start into the jungle on safari.”

“Or to use the common African term,” laughed Mr. Holton, “we’ll ‘push off into the blue,’ which means start into the unknown.”

The automobile that the naturalists had engaged was a well-known American make and had seen many miles of service but was still in good condition.

It was still early when the four placed their paraphernalia in the automobile and climbed in themselves. Mr. Holton took the wheel, sending the car ahead at a good pace.

The road was little more than a clearing cut out of the dense jungle, and in the rainy season would have been impassable. Now, however, it was in good condition.

“We’re out of the protectorate now, aren’t we?” inquired Bob, fingering his rifle.

“Yes. But to tell the truth,” began Mr. Holton, reading his son’s thoughts, “I’d rather you wouldn’t shoot anything along here. We’ll have plenty of that to do later.”

As a result of this, the chums refrained from using their rifles, although they saw numerous wild creatures that could have been brought down easily.

Just before nightfall, the little party of explorers chugged into Mbarara, which was a mere village at the edge of the primeval forest.

Here the explorers were welcomed by a huge Negro, to whom the automobile belonged. He was well acquainted with Mr. Holton and Mr. Lewis, having met them on their previous visit to this town.

“Boys,” said Mr. Lewis, addressing the chums, “I want you to meet Migo, an old friend of ours,” indicating the native. “Migo, this is Bob Holton and this, Joe Lewis.”

“Very glad know you,” greeted the native. He was a man of considerable importance in the country about Mbarara, and had picked up several languages, all of which he spoke well.

The chums exchanged the greeting and then made ready for anything that would be said.

“You gon’ org’ize another safari?” Migo asked the naturalists.

“Yes,” returned Mr. Lewis. “And we want you to help us find bearers. Will you do it?”

The answer came at once.

“I will,” the native said. “How many will you need?”

“We have come to the conclusion that twenty-five will satisfy our needs, at least for a while,” responded Mr. Holton. “If we need more we can pick them up at villages along the way. By the way, Migo,” he went on, struck with a sudden thought, “is it possible to get the guide we had last time? Kaika was his name. Knew every inch of ground for miles around.”

Migo’s face darkened. He shook his head slowly.

“Him not here any more,” he said in grave tones.

“Why—I don’t understand,” came from Mr. Lewis. “Where is Kaika?”

“Dead,” was the ominous response.

There was a short silence, during which the naturalists stared at Migo, hardly knowing what to say.

“I’m terribly sorry to hear that,” said Mr. Holton at last. “What caused his death?”

“He killed by a lion,” was the answer from the black. “It was a big man-eater. Kaika, he was in a village one day. Big man-eater he slip up on Kaika. Break Kaika’s back. He die in little time.”

The news sobered the Americans somewhat, for they began to realize anew that Africa, although a land of romance and adventure, was also a place of tragedy. Especially were Bob and Joe stirred by Migo’s words. This was the second casualty they had heard of since landing at the Dark Continent, the first being the case of Mr. Seabury in Mombasa.

“I sincerely hope nothing happens to our expedition,” said Mr. Holton gravely. “Especially since the boys are with us.”

The naturalists were delighted when Migo announced that he could secure the services of Noko, the native that Mr. Seabury had mentioned. For he was one of the very few who knew of the Forest of Mystery. He had recently returned from guiding another safari into a region far to the south. Migo assured the whites that he was unusually brave and daring and knew exactly which men to pick out for the expedition. He lived in a little hut at the edge of Mbarara.

“We’ll go there now,” said Joe’s father. “Migo, will you come with us? We may need your help.”

The native was more than willing, and together they went afoot, except for Mr. Holton, who drove the car. The automobile was now filled to capacity with supplies to be used by the expedition, several necessary additions being furnished by Migo, who kept a store.

In a small thatched hut they found an unusually tall coal-black native, who nodded as he greeted them.

“This Noko,” Migo introduced him. “This man his name Holton, this man name Lewis. These Bob and Joe.”

The towering native smiled broadly and bowed. Then he listened to what Migo had to say.

“They want you guide them into unknown land,” Migo resumed. “They want shoot, hunt. Will you do it?”

“Yes, bwana [master], I will go,” Noko said to the naturalists. “Where you want hunt?”

“In the Forest of Mystery,” said Mr. Holton. “You know where that is, do you not?”

Noko nodded vehemently.

“Yes, bwana,” he told them. “Noko been there two time. It ver’ strange place. See strange things. Strange animals. There some bad men dere. Use long spears. They kill hunters. Noko not see them, but hear about them. Baya sana [very bad]!”

“That is indeed unfortunate,” said Mr. Lewis. “But we are willing to take the chance, if you are.”

Noko bowed.

“It well, then,” he said. “Noko will go into strange forest. Noko not afraid.”

“And you can furnish the bearers?” asked Mr. Holton. “We’ll probably need about twenty-five, perhaps more.”

The tall native nodded. He explained that inside of two days he could complete preparations for the expedition and would let the whites know when he was ready.

After a few more words with Noko the naturalists and their sons left his hut and with Migo drove the automobile to a large clearing just off the roadway. Here they unloaded their supplies and pitched a tent.

“We’ll stay here until Noko has things ready for us to start into the jungle,” remarked Mr. Lewis, lifting a big box to carry it into the tent.

Late the next afternoon the Americans were resting under a large tree beside their temporary camp when they heard a shouting and yelling. Looking around they saw Noko and a large group of other natives heading toward them.

“Hurrah!” cried Joe. “Noko sure has acted quickly. Has everything ready for us.”

The natives were all capable of carrying loads of sixty pounds apiece. And Noko, as the neapara, or headman, assured the explorers that they could be relied upon.

Last-minute preparations were made. The naturalists saw that each porter was carrying his share of the provisions. Then, picking up their guns and handing them to their bearers, the scientists and the youths waved a farewell to Migo and several other natives who had gathered to see the expedition depart.

Led by Noko, the safari made its way toward a distant jungle.

They were off—off for the little-known Forest of Mystery!