“We’ll go on now,” said Ranni. He untied the raft and on they went again, caught by the strong current. Now they could see when branches of trees would scrape over the raft, and Ranni steered to avoid them.

The river wound in and out, and suddenly took a great curve, almost doubling back on itself.

“I hope it doesn’t flow back very far!” said Pilescu. “We don’t want to land back near the robber camp!”

The river did wind back a good way, and at one part, although the little company did not know it, it was only about a mile from the robbers! It had a strange course in the Secret Forest. It flowed half-way through, doubled back, and finally flowed out of the trees about six miles from where it first flowed in. The travellers did not know this, though Ranni could tell, by the position of the sun, that they were now travelling almost in the opposite direction.

The trees suddenly thinned, and sunshine flooded down here and there, almost dazzling the two men and the three boys. The river flowed more rapidly, and the raft bobbed about.

“We are coming out of the Secret Forest!” said Jack, shading his eyes and looking forward. “The trees are getting thinner and thinner. Where does this river go, I wonder? I do wish it would take us right through the mountains somewhere and out at the other side. Then we could just walk round them till we come to Killimooin Castle.”

“Not so easily done!” said Pilescu.

A shout made them turn their heads. To their horror, between the trees, they saw one of the robbers! He called out something, and then ran off to tell his comrades, his red wolf-tail swinging behind him.

Six or seven more came running with him after a few minutes, and they stood watching the raft as it swung along in the distance.

One robber yelled something after them. “What did he say?” asked Jack. Ranni looked a little solemn.

“He speaks a curious dialect,” he said, “But I think I understood him to say, “Soon, soon, you will be in the middle of the earth!” I wonder what he meant.”

Everyone thought about it. “Do you think it means that the river goes down underground?” asked Jack. “Well if it does, it’s what we want, isn’t it?”

“It depends on whether there is room for the raft or not,” said Ranni. “We must keep a sharp look-out.”

The river ran on. The boys saw the mountains of Killimooin around them. In front of them, slightly to the left, was the one they knew, on the other side of which Killimooin Castle was built. It looked very different from this side, but the summit was the same shape.

Suddenly they heard a terrific roaring sound ahead of them. Quick as thought Ranni plunged the tree-branch into the water and tried to steer the raft out of the current. But it was very swift and the raft kept on its course.

Jack saw that the big Baronian looked pale and anxious as he tried in vain to swing the raft from its steady course. “What’s the matter?” he asked.

“Can you hear that noise?” said Ranni. “I think the river makes a fall somewhere ahead — maybe a big waterfall. We don’t want to be caught in it. I can’t get this raft out of the current.

Pilescu suddenly slipped overboard, and, taking the raft with one hand, tried to swim to the shore with it. But he could not move it from the swift current.

“Jump!” he cried to the others. “Jump, and swim. It is our only hope. We are getting near the fall.”

Everyone jumped into the water. Paul was the weakest swimmer and big Ranni took him on his back. The raft went bobbing off by itself.

Pilescu helped Mike and Jack, but it was a stiff struggle to get to the bank of the swiftly-running river. They sat there, exhausted, hoping that no robber would come by, for they had no strength to resist anyone!

They recovered after a while. The hot sun dried their clothes, and steam began to rise from them.

“I wonder what happened to the raft,” said Jack.

“We’ll go and see!” said Ranni. “The noise is so tremendous here that the waterfall, or whatever it is, can’t be very far ahead. I think it must be where that fine mist hangs in the air over there, like smoke.”

They walked on beside the river, over rough ground. The noise became louder and louder. Then they suddenly saw what happened to the mountain river!

They rounded a big rock and came to the place where fine spray flew. The great silver river rushed by them — and then disappeared completely!

No river lowed ahead. The whole of the water vanished somewhere in that little place. Ranni went forward cautiously. He called to the others:

“It’s a good thing we got off the raft when we did! The river goes right down into the earth here!”

All the others joined Ranni. The spray soaked them as they stood there, trying to see where the volume of water went to.

It really was most extraordinary. There appeared to be a great cavern or chasm in the ground into which the river emptied itself with a terrific roar. The water fell into the enormous hole and completely disappeared.

“So that’s what the robber meant when he shouted that we should soon be in the middle of the earth,” said Jack. “That water must go deep down into enormous holes and crevices among the rocks. I suppose it goes right under the surrounding mountains and comes out somewhere else as a river again. How amazing!

“What a mercy we leapt off the raft!” said Mike, feeling scared at the thought of what might have happened if they and the raft together had plunged down into the heart of the earth. “Golly! This river has an exciting course! Through the mountain, down the slope, into the Secret Forest, out again, and down this chasm. Well — there’s no way out for us here, that’s certain.”

The five travellers left the curious place, and went to sit by a sun-warmed rock to dry their spray-wet clothes once more.

“The robbers must think we are all lost in the depths of the earth now,” said Pilescu. “They will not be on the watch for us any more. That is something to the good, at any rate.”

“What are we going to do?” asked Paul

“There is only one thing to do, my little lord,” said Pilescu. “We must go back the way we came!”

“What! Up into the mountain, beside the river all the way, and back to the temple-cave?” cried Paul. “Oh, we shall never do that!”

“We must,” said Ranni. “It is the only way out. I am going to climb a high tree so that I may see where the river flows out of the mountain.”

He climbed up the biggest tree nearby, and shaded his eyes for a long time. Then he came down.

“I cannot see where the river comes forth from Killimooin,” he said. “It is too far away. But I can see where the water enters the Secret Forest — or I think I can. We must go to the east, and walk until we come to the river. We cannot miss it, for it will lie right across our path!”

“Let us have something to eat first,” said Paul. “Where is the bread? There is plenty left, isn’t there?”

There was not plenty, but there was enough. They sat and ate hungrily. Then Ranni rose, and everyone got up too.

“Now to find the river again,” said Ranni. “We will skirt the Secret Forest until we come to the rushing water. Then we will follow it upwards to the mountain!”