The children read out the names of the towns they flew over. “Ortanu, Tarribon, Lookinon, Brutinlin — what funny names!”

“Look — there are mountains marked here. We ought to reach them soon.”

“The plane is going up. We must be going over them. Yes — we are. Look down and see. Golly, that’s a big one over there!”

“Aren’t the valleys green? And look at that river. It’s like a silvery snake.”

“Are we coming near the Secret Forest? Are we near Killimooin? Blow, I’ve lost it again on the map. I had it a minute ago.”

“Your hand’s over it, silly! Move it, Jack — yes, there, look! Killimooin. We’re coming to the mountains!”

Ranni yelled back to the children. “Look out for the Secret Forest! We are coming to the Killimooin range now. Paul, you know it. Look out now, and tell the others.”

In the greatest excitement the five children pressed their faces against the windows of the big plane. It was rising over steep mountains. The children could see how wild and rugged they were. They could not see anyone on them at all, nor could they even see a house.

“Now you can see how the Killimooin Mountains run all round in a circle!” cried Paul. “See — they make a rough ring, with their rugged heads jagged against the sky! There is no valley between, no pass! No one can get over them into the Secret Forest that lies in the middle of their mighty ring!”

The children could easily see how the range of mountains ran round in a very rough circle. Shoulder to shoulder stood the rearing mountains, tall, steep and wild.

The aeroplane roared over the edge of the circle, and the children gazed down into the valley below.

“That’s the Secret Forest!” shouted Paul. “See, there it is. Isn’t it thick and dark? It fills the valley almost from end to end.”

The Secret Forest lay below the roaring, throbbing plane. It was enormous. The tops of the great trees stood close together, and not a gap could be seen. The plane roared low down over the trees.

“It’s mysterious!” said Nora, and she shivered. “It’s really mysterious. It looks so quiet — and dark — and lonely. Just as if really and truly nobody ever has set foot there, and never will!”

The aeroplane rose high again to clear the other side of the mountain ring. The forest dwindled smaller and smaller. “Go back again over the forest, Ranni, please do!” begged Jack. “It’s weird. So thick and silent and gloomy. It gives me a funny feeling!”

Ranni obligingly swung the big plane round and swooped down over the forest again. The trees seemed to rise up, and it almost looked as if the aeroplane was going to dive down into the thick green!

“Wouldn’t it be awful if our plane came down in the forest, and we were lost there, and could never, never find our way out and over the Killimooin mountains?” said Nora.

“What a horrid thought!” said Peggy. “Don’t say things like that! Ranni, let’s get over the mountains quickly! I’m afraid we might get lost here!”

Ranni laughed. He swooped upwards again, just as Jack spotted something that made him flatten his nose against the window and stare hard.

“What is it?” asked Nora.

“I don’t quite know,” said Jack. “It couldn’t be what I thought it was, of course.”

“What did you think it was?” asked Paul, as they flew high over the other side of the mountain ring.

“I thought it was a spiral of smoke,” said Jack. “It couldn’t have been, of course — because where there is smoke, there is a fire, and where there is a fire, there are men! And there are no men down there in the Secret Forest!”

“I didn’t see any smoke,” said Mike.

“Nor did I,” said Paul. “It must have been a wisp of low-lying cloud, Jack.”

“Yes — it must have been,” said Jack. “But it did look like smoke. You know how sometimes on a still day the smoke from a camp fire rises almost straight into the air and stays there for ages. Well, it was like that.”

“I think the Secret Forest is very, very strange and mysterious,” said Peggy. “And I never want to go there!”

“I would, if I got the chance!” said Mike. “Think of walking where nobody else had ever put their foot! I would feel a real explorer.”

“This is Jonnalongay,” called Ranni from the front. “It is one of our biggest towns, set all round a beautiful lake.”

The children began to take an interest in the map again. It was such fun to see a place on the big map, and then to watch it coming into view below, as the aeroplane flew towards it. But soon after that they flew into thick cloud and could see nothing.

“Never mind,” said Ranni. “We have turned back now, and are flying along the other border of Baronia. It is not so interesting here. The clouds will probably clear just about Tirriwutu, and you will see the railway lines there. Watch out for them.”

Sure enough, the clouds cleared about Tirriwutu, and the children saw the gleaming silver lines, as Pilescu took the great plane down low over the flat countryside. It was fun to watch the lines spreading out here and there, going to different little villages, then joining all together again as they went towards the big towns.

“Oh — there’s the big palace by the lake!” said Nora, half-disappointed. “We’re home again. That was simply lovely, Paul.”

“But the nicest part was Killimooin and the Secret Forest,” said Jack. “I don’t know why, but I just can’t get that mysterious forest out of my head. Just suppose that was smoke I saw! It would mean that people live there — people no one knows about — people who can’t get out and never could! What are they like, I wonder?”

“Don’t be silly, Jack,” said Mike. “It wasn’t smoke, so there aren’t people. Anyway, if people are living there now, they must have got over the mountains at some time or other, mustn’t they? So they could get out again if they wanted to! Your smoke was just a bit of cloud. You know what funny bits of cloud we see when we’re flying.”

“Yes, I know,” said Jack. “You’re quite right, it couldn’t have been real smoke. But I rather like to think it was, just for fun. It makes it all the more mysterious!”

The aeroplane flew down to the runway, and came to a stop. The mechanics came running up.

“You have had the best of it today!” one called to Ranni, in the Baronian language, which the children were now beginning to understand. “We have almost melted in the heat! This sun — it is like a blazing furnace!”

The heat from the parched ground came to meet the children as they stepped out of the plane. Everything shimmered and shook in the hot sun.

“Gracious!” said Nora. “I shall melt! Oh for an ice-cream!”

They walked to the palace and lay down on sunbeds on the terrace, under the big colourful umbrellas. Usually there was a little wind from the lake on the terrace — but today there was not a breath of air.

“Shall we bathe?” said Jack.

“No good,” said Mike. “The water was too warm to be pleasant yesterday — and I bet it’s really hot today. It gets like a hot bath after a day like this.”

A big gong boomed through the palace. It was time for lunch — a late one for the children. Nora groaned.

“It’s too hot to eat! I can’t move. I don’t believe I could even swallow an ice-cream!”

“Lunch is indoors for you today,” announced Ranni, coming out on to the terrace. “It is cooler indoors. The electric fans are all going in the play-room. Come and eat.”

None of the children could eat very much, although the dishes were just as delicious as ever. Ranni and Pilescu, who always served the children at meal-times, looked quite worried.

“You must eat little Prince,” Ranni said to Paul.

“It’s too hot,” said Paul. “Where’s my mother? I’m going to ask her if I need wear any clothes except shorts. That’s all they wear in England in the summer, when it’s holiday-time and hot.”