They had seen the boat on the beach, and had come to examine it. They soon saw that it was the stolen boat, which had now been missed and was being searched for.

The men knew at once where the owner of the boat was—in the eavel And they were going to search for him there.

Tom darted back into the Round Cave and hid be-hind a big pile of boxes. He felt quite certain he would be found—and as he crouched there, trembling and excited, he made up his mind very, very firmly that he would not say how many others had come to the islands with him. He would make the men think that he was the only one—then nlaybe the other three would not be hunted for.

"I've been a perfect silly to run into danger like this," thought poor Tom. "But, at any rate, I can save the others from being hunted for, perhaps."

The men came into the Round Cave. They had powerful torches which they flashed around—and almost at once they saw Tom's feet sticking out from behind a box.

They dragged him out and stood him up. They seemed most astonished to find only a boy. They had expected a man. They talked quickly among themselves in a language that Tom could not understand.

Then one man, who could talk English, spoke to Tom. "How did you get to this island?"

"I set off in a sailing-boat and a storm blew up and wrecked me," said Tom. "You can see my boat off the coast of the next island, if you look."

"Is there anyone else with you on this island?" asked the man. "Speak the truth."

Tom could reply quite truthfully that there was no one else with him on the island! Thank goodness, the others were on the first island!

"There isn't anyone else here with me," he answered. "Search the cave, and see!"

The men did search the cave again, but found nobody, of course. They did not seem satisfied, however. Tom could see that they felt sure there were others to find.

"How did you find this cave?" asked the man who spoke English.

"By accident," said Tom.

"And I suppose you also found our boat by accident, and saw the submarines by accident?" said the man, in a very nasty voice. "Are you sure there is no one else here with you?"

"Quite sure," said Tom. "Wouldn't you see them in the cave, if there were?"

"We shall not take your word for it," said the man, with a horrid laugh. "We shall search this island and both those next to it—and if we find anyone else, you will be very, very sorry for yourself!"

"You won't find anyone!" said Tom, hoping to goodness that they wouldn't, and wishing he could warn Andy and the girls somehow. "Are you going to keep me prisoner?"

"We certainly are," said the man. "And as you seem so fond of ibis cave, we'll let you stay here! You've food to eat—and you won't be able to do any spying round if you're here in this cave! We shall put a man on guard at the entrance—so if you try to get out, or anyone else tries to get in, you'll be caught. Our man will be well hidden behind a rock at the entrance—and if any friends of yours try to rescue you, they will get a shock!"

Tom listened, his heart sinking into his shoes. What an idiot he had been! He was to be a prisoner—and it the others tried to find him they would be made prisoners too, for they would never guess a sentry was hidden behind the rocks, watching for them.

Tom sat down on a box. He would not cry. He would not show the men how frightened and worried he was. His face was brave and bold—but inside he felt as if he was crying buckets of tears! If only, only he could get word to Andy!

There was nothing he could do—nothing! He could only sit there in the cave, surrounded by marvellous food that he felt too worried even to look at, and think about the others. Poor Tom! It was a dreadful punishment for being careless enough to forget his camera, and foolish enough to try and fetch it!

The men left a lamp in the cave for Tom. It was getting late and the boy was tired—but he could not sleep. He heard the men go out, and he knew a sentry had been placed by the rocks. He could not hope to escape. But he could try!

So, very quietly, he made his way through the rocky archway, down to the shore-cave below. But his feet set the stones moving here and there, and a voice came out of the darkness.

He could not understand what was said to him, but the voice was so stern that the boy fled back to the Round Cave at once. It wasn't a bit of good trying to escape.

He sat down again and wondered about the others. What were they thinking and doing? Would they guess he had gone to fetch his camera, and come to look for him when the tide uncovered the rocks next day? If so, they would certainly be caught.

Andy and the girls sat up until they could keep awake no longer. They went back to the shack, curled up on their beds, and slept restlessly, worrying about Tom and the lost boat.

In the morning, Andy went out cautiously, wondering if the enemy had already landed a boat on their island to hunt for them. But he could see nothing strange.

He sat talking to the girls as they prepared breakfast. "Tom is certainly caught." he said. "There's no doubt about that, I'm afraid. Well. I know enough of Tom to know that he won't say we are here, too. He won't give us away. But they will certainly come and hunt for anyone else who might be here. We have to do two things—hide ourselves so that we can't possibly be found—and then think of some way of rescuing Tom."

"Oh dear! It seems quite impossible," said Jill, feeling very worried. Mary began to cry.

"Don't cry, Mary," said Andy, putting his arm round her. "We have to be brave now. We are British children, and so we have plenty of courage and heaps of ideas. We must all think hard and see what we can do to trick the enemy."

"But, Andy, how can we hide on this bare island?" said Mary, drying her eyes and blinking away her tears. "They will beat all through the bracken and heather. There are no good trees to hide in. Not a single cave. Really, there isn't anywhere at all!"

"You're right. Mary," said Andy. "It's going to be very difficult. But we must think of something. You see, if only we can hide and not be found we can somehow think of a way to rescue Tom—but if we are found we can't help Tom, and won't be able to escape and tell our secret!"

"Yes—it's very, very important," said Jill thoughtfully. "Let's think of ways of hiding. The bracken is no use at all, is ft?"

"Not a bit of use," said Andy. "I did think we might perhaps wade out to the ship and hide down in the cabin—but I know they would look there."

"Could we hide in the shack?" asked Mary. "Pile the heather over ourselves, or something?"

"No," said Andy. "The shack's no use. We should be discovered there at once. And there's no place in any of the other old ruined buildings. I wish we knew of a cave or something like that."

"It's a good thing we've got plenty of food hidden in the sand," said Jill. "If we can manage to hide ourselves away we need not starve! We've only got to go and dig up that store of food!"

"Yes—that's very lucky," said Andy. "I say, listen!. That's the sound of a motor-boat, isn't it?"

Andy crept out to see, keeping well under cover. Yes—there was a motor-boat coming round the corner of the island—a motor-boat with five men in it!

"They're coming!" whispered Andy. "They're in a motor-boat. Quick—where shall we hide!"

"We'd better rush over to the opposite side of the island," said Jim, her face pale. "The first place they'll hunt is this side, where they land.XJuick, Mary!"

The three children slipped out of the shack and made their way up the rocky path. They were just out of sight when the motor-boat landed on the beach. They would be able to reach the other side of the island unseen—but what could they do there? The shore there was nothing but rocks and sand—they would be found in two minutes!