Jack really didn’t know what to do. It was no use at all going back - and he certainly couldn’t go forward unless he wanted to struggle with the tide in the cave.

“And I don’t want to do that.” thought the boy, listening to the smack and gurgle of the big waves that swept into the large cave below. “What in the world am I to do?”

He suddenly thought that he could hear someone coming down the secret passage. He looked round the small cave in despair. Could he lock the door that led into the cave? No - the lock was broken many years ago.

He flashed his torch round the little cave. He suddenly saw a small hole in one corner. He bent down and shone his torch into it. It was a hole big enough for a small man to get through - but where did it lead?

There was no time to be lost. Jack wriggled through the hole somehow. It widened out a little in a moment or two and dipped down into the next cave. But as that was also full of swishing waves Jack could go no farther. The hole was simply a connection between the two caves, it seemed.

“Well, I simply can’t do anything but wait here.” thought Jack. So he waited - and in a minute or two he heard the sound of people in the cave he had left, and heard voices.

“He’s not here, Luiz,” said the voice of Mr. Diaz. “And he couldn’t possibly have gone down through the shore-cave, surely, or he would have been drowned.”

“Maybe he has tried, though,” said Luiz. “He might have been very frightened, and have leapt into the water and tried to swim away.”

“Well, if so, he’s gone,” said Mr. Diaz. “I can’t imagine that any one could swim down there! Listen to the water sucking in and out. It would be impossible even for a man to swim through that.”

“Well, if he didn’t go down there, where is he?” said Luiz rather sharply. “You don’t suggest that he is hiding in any of these small boxes, do you?”

“That’s enough, Luiz,” said Mr. Diaz, in an angry tone. “I can’t understand the whole thing - how did that boy get into the grounds and the house when the dogs were there? And how did he know about the secret passage? Where has he gone now? And what do you suppose he knows about the prince?”

“Well, if you really want to know what I think, I think that Anna the cook made a mistake,” said Luiz, sounding very bored. “I think maybe something fell down in the scullery, and Anna rushed in - and thought she saw a boy! And she screamed and made a fuss.”

“Well, maybe you’re right,” said Mr. Diaz. “Come on, let’s go back. He’s not here, anyway.”

Jack heard their scrambling footsteps going from the cave. For a while he caught the sound of their voices as they went up the secret passage. Then there was silence.

“My word, that was a narrow escape!” thought Jack. “Good thing I found this hole. I wonder if the tide is going out? It sounds less strong.”

He wriggled himself into a different position, and was then able to switch on his torch and see the cave below. It was the one next to the large cave, and was only small. The sea was leaving it.

“It’s safe to get down,” thought the boy, and he wriggled out of the small passage, slid down the cave wall and jumped down to the wet sand. A wave immediately ran into the cave and wetted Jack to the waist.

“You would!” said Jack to the wave. “Just waiting for me, I suppose!”

The wave ran out. Jack ran quickly to the cave entrance and looked up the beach. If he were quick, and dodged in between the big waves that ran up the sand and back, he could get up on the rocks, and climb along them to the cliff-path.

Another wave ran up and Jack ran back into the cave to escape it. It swirled around his knees and nearly knocked him over. As soon as it ran out Jack ran out after it. He jumped quickly up on the rocks at the foot of the steep cliff. Another wave swept up and wetted his legs - but Jack clung to the rock and was safe.

He climbed a bit higher on to the rocks. Now the sea could hardly reach him, and as it was going down he would soon be safe.

He clambered over the rocks, stumbling and slipping on the seaweed. He came to the cliff-path and put his feet on the steps cut out of the rock. He switched on his torch and went carefully up to the top of the cliff.

A wind was blowing there. Jack switched off his torch in case anyone saw its light, and made his way softly back to Peep-Hole. The gate creaked as he opened it. He was safe home at last!

He ran up the winding staircase and into his bedroom at the top. The others were there. And they crowded round him at once.

“Jack! Jack! What an age you’ve been! Were you nearly caught again?”

“You just listen to what happened to me to-night!” said Jack. “I have had a time, I can tell you! My word, we had plenty of adventures on our secret island last year, but to-night’s adventure was the most exciting of all!”

Jack told the others of his adventures that night. They listened in silence. When he came to the part about how he escaped down the secret passage to the shore, and could not get down into the cave because of the tide, Nora took hold of his hand tightly.

“You’re not to go on adventures alone any more, Jack,” she said. “Suppose you had been caught! We wouldn’t have known where you were! Please, please, let us all go together in future, when there is anything to be done.”

“We’ll see,” said Jack. “Sometimes it’s impossible for the whole lot of us to go together - we’d be noticed.”

“All the same, Nora’s right.” said Mike. “I think we ought to go out in pairs, Jack. You have had a time. What’s going to be our next move?”

“Bed,” said Jack at once. “I’m so sleepy I can’t keep my eyes open! We’ll decide to-morrow what is to be done.”

The girls went down to their bedroom. Jack and Mike tumbled into their beds, and were soon asleep. Once again Dimmy had to wake them all, for they were so sleepy the next morning!

“You have turned into sleepyheads!” said Dimmy, in surprise. “You will be very late for breakfast, so hurry up, please.”

The children put on their sun-suits, and raced downstairs. It was a beautiful sunny day, and they meant to bathe as soon as they could.

“Not till two hours after breakfast, remember,” said Dimmy warningly. “It is dangerous to bathe after a big meal. Jack, I can trust you not to let the others do anything foolish, can’t I?”

“Jack’s our captain, Dimmy,” said Nora. “We always do what he says.”

They went down to the beach, taking with them a basket of ripe plums from the garden for their eleven o’clock lunch. They chose a rock far down the beach, that the tide was already lapping round, and sat on it.

“It’s best to be in some place where we can’t possibly be overheard.” said Jack, looking all round. “Now that Mr. Diaz thinks one of us knows the secret of the prisoner in the tower, and all about the secret passage too, we shall have to be extra careful. I think Nora’s right when she says we must go about together. Mr. Diaz and Luiz would be pleased if they could catch any of us and keep us prisoner too!”

“Let’s talk about rescuing Prince Paul,” said Nora, who was longing to get the boy out of the tower. “Couldn’t we take the rope-ladder along to-night, Jack? Now that you’ve made friends with the dogs, it would be easy.”

“Well, I don’t know if the dogs would be friends with you too,” said Jack doubtfully. “We could try. No - I know what we’ll do. I’ll take Mike along with me to help, and you two girls can stay behind. We’ll signal a message to Prince Paul with our big black letters to-day, then he will be ready to look out for the ladder to-night.”

The girls were disappointed at the thought of being left behind, but they made no fuss. It was no use all of them going if the dogs barked at them and warned Mr. Diaz that they were about. Perhaps they would be all right with just Jack and Mike.