As the police surround him, he threatens to throw the girls over the side. The hero manages to get into the same car and there is a terrific fight at the end, as the old roller coaster swoops up and down and around."

"Terrific!" Bob said. "And in this spooky old park it'll be the most! I can hardly wait to see it."

"If we shoot it here," Mr. Crenshaw said gloomily. "Well, we'll see. You boys can look round. Come back in half an hour. Jeff Morton ought to be back from the mainland by then."

He started away, then paused.

"Whatever you do," he said, with a look half worried and half humorous, "please don't find any treasure! Repeat, don't find any treasure! This was once a pirate hangout, you know."

"Yes, sir," Bob answered. "We've read all about the pirates and the treasure and the capture of Captain One-Ear."

"People never seem to give up," Mr. Crenshaw shook his head. "This island must have been dug up by large expeditions at least twenty times since then. Luckily, during the last fifty years not a doubloon has been found, so the treasure fever has died out. But knowing you boys, nothing would surprise me not even your finding treasure where there isn't any!"

"Will it be all right, sir, if we explore the cave?" Bob asked. He pointed to the one hill on the island. "The old maps show a cave up at the top of that hill. The stories say it was used by the pirates to hold prisoners for ransom, but no treasure was ever found there."

"Yes, you can explore the cave," Mr. Crenshaw agreed. "But be back in half an hour." He turned and walked away. The boys stood staring round them at the ruins of Pleasure Park. "It sure is creepy here all right," Pete said. "But that roller coaster scene will be terrific. It's scary just to think about."

"Jupe, you haven't said much," Bob said. "What're you thinking about?"

The First Investigator was looking very thoughtful.

"Your dad, Pete, and the others," he said, "seem to think that some of the fishermen are responsible for the thefts that have been going on, either for mischief or to steal something valuable. But I don't think so."

"You don't? What do you think?" Pete asked.

"The sabotage of the boats and the thefts of equipment," Jupiter said, "seem designed to get the movie company so fed up with Skeleton Island they'll move away and shoot the end of the picture somewhere else. This island has been deserted for twenty-five years and it is my deduction that someone wants it to stay deserted, and is deliberately trying to annoy Mr. Denton into abandoning the project."

"Want the movie company to leave!" Pete said blankly. "Why would anybody care if they left or not?"

"That is the mystery," Jupiter acknowledged. "Now let's go and see the old cave."

Ten minutes trudging uphill through scraggly trees brought them to a cave near the top of the rocky hill. The entrance was small, and the interior dark. However, once they were inside, there was light enough to see that they were in a roomy cave that went back quite a distance, narrowing towards the rear.

The soil of the cave was loose. It looked as if it had been dug up many times. Jupiter picked up a little of the sandy dirt and nodded.

"Many people have dug here for treasure," he said. "I daresay every inch of this cave was examined several times in the past hundred years. However, no sensible pirate would ever hide his treasure here. He'd look for a place less noticeable."

"Yeah," Pete agreed. "Wish we'd brought our flashlights. I'd like to look around in the back there."

"You're not as much of an investigator as I thought, Pete," Jupiter said, grinning.

"You either, Bob. Look at me."

They looked with surprise as Jupiter unclipped a flashlight that was hanging from his belt.

"Primary equipment for any investigator," Jupiter said loftily. "However, I'll admit I remembered the cave, too, and planned on looking into it if we got the chance.

Otherwise I might not have thought of it either."

He beamed the light towards the low back part of the cave. Some fiat rocks looked worn smooth, as if imprisoned men had once lain on them as very hard beds. Jupiter's flashlight flicked over other rocky crevices and ledges until, at a point about six feet above the ground, it stopped suddenly.

Something white rested there on the ledge of a rocky shelf. Something white and round. Bob gulped. It was a human skull.

It seemed to grin at them. And then, just as Bob was reminding himself that it was only a bony memento of the bad old pirate days of long ago, the skull spoke to them.

"Go 'way," it sighed, with a strong accent that sounded Spanish to Bob. "Let me 'ave my rest. No treasure is here. Only my tired old bones."

Gold Doubloons

BOB FOUND that his feet had automatically turned to take him out of the cave. In another moment he and Pete were racing each other for the outside, with Jupiter not far behind. Bob and Pete collided and sprawled headlong at the entrance.

Jupiter, however, had turned back. He picked up the flashlight he had dropped and shone it on the skull.

"Skulls can't talk," he informed the aged death's head, "because to talk you need a tongue and larynx. Therefore logic tells me you did not speak."

Bob and Pete, picking themselves up outside the cave, suddenly heard whoops of laughter. Puzzled and a little embarra.s.sed, they went back inside.

Chris Markos, the boy of the night before, was climbing down from a niche in the ricky wall.

"Hi," he said, tossing the old skull behind him. "Remember me?"

"Of course we remember you," Jupiter said. In fact, I had already deduced it was you because earlier I saw a sailing-boat ahead of us that looked like yours. Besides, the voice that spoke was too youthful to be anything but a boy's."

"I scare you, yes?" Chris grinned. "You think dead pirate is talking to you."

"You startled me," Jupiter corrected him. "You scared Pete and Bob, though."

Bob and Pete looked sheepish.

"You didn't scare me me," Bob said. "You scared my legs. I didn't know they were going to run until they did."

"Me, too," Pete agreed. "When a skull starts talking, my legs want to be some place else."

"Good joke!" Chris still radiated merriment. "I hope you will not be mad, though. It is just for fun."

"No, we're not mad. We've been wanting to talk to you. Let's go outside in the sun."

Jupiter led the way outside and all four boys stretched out, their backs against a rock.

"How did you happen to be here?" Jupiter asked the Greek boy. "I mean in the cave and everything, waiting for us?"

"Easy," Chris said. "I am sailing, and I see boat take you to the pier. I sail round the island and pull up my boat on the beach. I slip through trees, and see you at the old merry-go-round. I hear you say you are going to explore the cave. I know a short-cut, so I get there first. Then I think of this good joke with an old skull I know is up on one of the rocks. I climb up and hide and wait for you."

That explained everything, but Bob wanted to know why Chris had hidden. Why hadn't he come out and said h.e.l.lo earlier?

"The guard," Chris said simply. "That Tom Farraday always chases me away.

Everybody chases me away."

His cheerful grin was suddenly gone.

"I have a bad name in town," he said slowly. "People think I am a thief, because my father and I are poor. And different. From a foreign country. In town are some people who are not good. They steal things and say Chris the Greek does it. But I do not do it!"

They believed him. It was an old trick, they knew, to blame things on an outsider.

"We believe you're honest, Chris," Pete said. "One thing puzzles us, though. How did you find us so quickly last night?"

"Oh, that," Chris said, grinning again. "I do some work in a place called Bill's Tavern. I sweep, wash dishes, get two dollars a day. My father and me, we live on that.

Mr. Bill is a nice man."

"Two dollars a day!" Bob exclaimed. "How can you live on that?"

"Live in an old, abandoned fishing shack, no tent," Chris explained soberly. "We eat beans and bread and I catch many fish. But father, he is sick. He needs good food. So all the extra time I have, I sail around the bay, hoping to find big treasure. But I am foolish, I guess. Some treasure lies on the bottom of the bay. But what chance has Chris Markos to find lots of it?"

"You have as much chance as anybody!" Pete said. "But you were going to tell us how you knew where to look for us."

"Oh, sure. Yesterday I am washing dishes. I hear men talking in the last booth of tavern. One says, 'Three kid detectives, huh? Well, I'll hand them a surprise. I'll hand them something they won't forget!' Then they all laugh."

Jupiter pinched his lip thoughtfully. "Tell me, Chris, when this man spoke the word 'hand' did he do it with special emphasis?" he asked.

"He means did he say 'hand' in some special way?" Bob interpreted as the Greek boy looked puzzled.

"Oh, yes he does!" Chris exclaimed. "Each time he says 'hand' he makes the voice deeper and louder. So when I hear three boys are missing, I think to myself, where could anyone hide three boys? Then I remember the funny way that man says 'hand'."

"And you deduced that he was referring to the island called The Hand!" Jupiter exclaimed.

"That is just what I think. So I sail out as soon as the storm is over. And I find you right there, on The Hand. Only " and Chris's face clouded again "now movie people think that I had something to do with it. n.o.body believes good of me."

"We believe in you, Chris!" Bob said stoutly.

Chris smiled. "You believe in me, I show you something."

His hand went beneath his pullover and out came a little well-oiled leather sack.

Chris loosened the draw string.

"Hold your hands out," he said. "Close your eyes. Do not look until I say."

They obeyed. Something warm and heavy was placed in each boy's palm. When they opened their eyes, each was holding an antique gold piece!

Bob examined the worn, but still shiny coin. "Sixteen fifteen!" he exclaimed.

"Spanish doubloons!" Jupiter said, his eyes shining. "Real pirate treasure!"

"Golly!" Pete said in awe. "Where'd you find them?"

"In the water, lying on sand. There is plenty of treasure in bay Captain One-Ear, he dumped his whole treasure overboard a long time ago. But now it's all scattered, a little here, a little there. Very hard to find any. I dive and dive. One piece I find off the other end of Skeleton Island, near wreck of nice yacht. But I find two right together in one special little bay where I think maybe "

At that moment a loud, angry voice interrupted them.

"Hey! You, Chris! What're you doing here?"

Startled, they looked up. Tom Farraday, the normally good-natured guard, was puffing up the path towards them, his face dark with anger.

"I told you if I caught you hanging round any more, I'd give you a whaling!" Tom Farraday cried. "Those are my orders and "

He stopped. The boys turned and followed his gaze. But Chris Markos had disappeared behind a rock as silently as a shadow.

Danger Underwater

"WHAT DID that kid want?" Tom Farraday demanded. "Why did he bring you boys up here?"

"He didn't want anything special," Jupiter told him. "And he didn't bring us up here. We came up to look at the cave."

"Well, let me tell you, that Chris is no good!" the guard said. "If n.o.body's actually caught him stealing anything yet, it's because he's too smart. Take my advice and stay away from him. Now come along. Jeff Morton is back and wants to do some diving with you."

As they started down the trail, Tom's manner became more friendly.

"I suppose you were hoping to find some treasure in that cave," he said. "Well, there isn't any and never was. What's left is scattered over the bottom of the bay. Once in a long while a piece turns up on a beach, but people have got tired of even hunting for it any more, it happens so seldom."

He chuckled.

"When Davy Jones takes something, he doesn't often give it back. Did you know that he took a hundred thousand dollars in good American cash only ten years ago? Yes sir, he took it and kept it. And because of that hundred thousand dollars my left arm got crippled and I've been this way ever since, only able to do odd jobs."

He moved his stiff left arm to show what he meant. The boys clamoured for the story, and Tom willingly obliged.

"Well, boys," he said, "I used to be a guard on an armoured car for the Dollar Delivery Company. One of our jobs was to pick up cash from the local banks and take it to the big national bank in Melville.