"I wonder," said Jupiter Jones, "if we could steal the Rainbow Jewels."
His question took his two companions by surprise. Pete Crenshaw almost dropped a soldering iron, and Bob Andrews did drop the composing stick he was using to set up type for their old printing press.
"What did you say?" he demanded, looking in dismay at the spilled type.
"I said I wonder if we could steal the Rainbow Jewels," Jupiter repeated, "if we were thieves, that is."
"Which we are not," said Pete firmly, "Stealing jewels is dangerous. People shoot at you and chase you. Anyway, I believe in that old stuff about honesty being the best policy."
"Agreed," said Jupiter. But he continued to stare thoughtfully at the newsletter he had been reading.
The three boys, who called themselves The Three Investigators, were in Jupiter's secluded workshop section of The Jones Salvage Yard. Here, out of doors but under a six-foot roof that extended from the Salvage Yard's tall fence, they worked on rebuilding junk that came into the yard. The part of the profits they received from Jupiter's Uncle Titus kept them in pocket money and helped them pay for such luxuries as a telephone in their hidden Headquarters.

"I wonder," Jupiter Jones said one morning, "how we would go about attempting the biggest robbery ever seen in this area."
His two companions reacted with surprise. Bob Andrews dropped the stack of small cards he was feeding into their old printing press. Pete Crenshaw, who was mending an old radio, jerked and saw his srewdriver glance off in an erratic arc.
"What was that you said?" Pete asked, trying to smooth out the jagged scratch he'd made on the wooden back of the radio.
"I said I wonder how we would go about attempting the biggest robbery ever tried in this area," Jupiter repeated. "That is, if we were master criminals."
"While you're wondering," Pete said, "try to find out what happens to us after we get caught. I heard somewhere that crime doesn't pay."
Bob Andrews picked up the scattered cards he had dropped. "I don't think we'd be good at being master criminals. I can't even master putting cards into this printing press."
"It was merely a thought," said Jupiter. "After all, we are investigators. It occurs to me that if we could imagine a well-planned crime, we'd be ahead when it came to solving it. All we need to do is reverse our thinking and assume the anti-social mind of a mastermind criminal."
Pete nodded. "That's a neat idea, Jupe. But first I've got to reverse the thinking of the last owner of this radio. He tried to mend it himself and got the wires all twisted. After that, I'll be willing to play mastermind games with you."
The three boys, who called themselves The Three Investigators, were in Jupiter's workshop section of The Jones Salvage Yard. Secluded here, under a six-foot roof extending from the junk yard's high fence, they worked on repairing junk that Jupiter's Uncle Titus bought. They used part of the profits for pocket money and part for such luxuries as the telephone in their secret headquarters.

At that moment the telephone rang.
After the third ring Jupiter reached for it, switching on the little radio loudspeaker, which enabled them all to hear what was said.
"Jupiter Jones?" asked a woman's voice. "Alfred Hitchcock calling."
"Maybe he has a case for us!" Bob yelled. Since Mr Hitchcock, the famous motion picture director, had become interested in The Three Investigators, he had steered them to several exciting cases.
"Hello, young Jones!" It was Mr Hitchcock speaking. "Are you busy on a case just now?"
"No, sir!" Jupiter said. "That is, we offered to help the Peterson Museum solve the Golden Belt robbery, but they said we were too young."
Mr Hitchcock chuckled.
"They should have let you try," he said. "Judging by the papers, you couldn't do any worse than the police. However, I'm glad you are not busy. You may be able to help an old writer friend of mine."
"We'd be glad to try, Mr Hitchcock," Jupiter said. "What is your friend's trouble?"
Mr Hitchcock paused, as if trying to think of the right words.
"I'm not quite sure, my lad," he said. "But on the telephone she told me she is being bothered by gnomes."
"Gnomes, sir?" Jupiter's tone was baffled. Pete and Bob, listening, were equally perplexed.
"That's what she said, my boy. Gnomes. Little people, relatives to dwarfs and elves, who wear leather clothes and live underground and dig for treasure."
"Yes, sir," Jupiter answered. "I mean we know what gnomes are – if there actually are any, that is. They're supposed to be mythological and imaginary."
"Well, my friend says they're real! They sneak into her house at night and change all her pictures and books around. They have her very worried, and she wants someone to help her chase them away. She mentioned them to the local policeman and he gave her such a funny look that she refuses to say anything more to anyone she can't trust."
There was a brief silence.
"So what do you say, my boy? Can you help her out?"
"We'll certainly try, sir!" Jupiter said excitedly. "Just give me her name and address!"
He wrote down the information Mr Hitchcock gave him, promised they would report all progress as soon as possible, and hung up. He looked at Bob and Pete triumphantly.

At that moment the telephone rang.
The boys looked at one another. Hardly anyone ever phoned them.
After the second ring, Jupiter reached for it, switching on the little radio loudspeaker.
"Jupiter Jones?" asked a woman's voice. "Alfred Hitchcock is calling."
"Wow!" Bob yelled. "Maybe he has another good case for us!" Ever since Mr Hitchcock, the famous film director, had learned of The Three Investigators, he had put them on several cases.
"Hello, young Jones!" It was Mr Hitchcock speaking. "Are you and your friends busy on a case at the moment?"
"No, sir," Jupiter said. "But according to the law of averages we should find something interesting soon."
Mr Hitchcock chuckled.
"Law of averages, indeed!" he said. "If you're not busy, I have something for you. An old film director friend of mine can use some help."
"We'd be glad to try, Mr Hitchcock," Jupiter said. "What is your friend's problem?"
Mr Hitchcock hesitated, as if he were trying to sum up a difficult situation in a few words.
"It appears to be dog trouble," he said finally. "That is to say, he told me on the telephone a little while ago that his dog is missing."
Jupiter's eyes brightened. "Would your friend happen to be a resident of the town of Seaside, Mr Hitchcock?" he asked.
There was a brief silence.
When Mr Hitchcock came on again, he sounded thunderstruck. "He does live in Seaside, for a fact, young Jones. Now how on earth did you deduce that?"
"Merely putting a few odd occurences together," Jupiter said.
"Remarkable," Mr Hitchcock was saying. "Quite remarkable, really. I'm pleased that you are still alert and not permitting your organization to become stagnant with conceit and boredom."
Jupiter grinned. "Not a chance, Mr Hitchcock. But you said, your friend 'appears' to be having dog trouble. You put stress on the word 'appears,' sir. Was that your intention?"
"As a matter of fact," Mr Hitchcock said, "you have guessed quite accurately what I was intending to communicate. I don't believe this is an ordinary case, at all. When you think of it, no case that involves a dragon can be considered ordinary. Wouldn't you agree?"
Jupiter cleared his throat. "A dragon?"
"Yes, my boy. My friend's house overlooks the ocean, and there are caves running beneath it. The night that his dog disappeared, my friend insists he saw a rather large dragon emerge from the ocean and enter one of the caves underneath his dwelling."
There was a stunned silence.
"Well, what do you say, my boy? Are you and your companions willing to try to unravel this mystery?"
Jupiter was so excited, he started to stutter. "J-j-just give me your friend's name and address, sir!" he said. "This sounds as if it could be our most exciting case!"
He wrote down the information Mr Hitchcock gave, promised to report all progress, and hung up. He looked at Pete and Bob triumphantly.

And then the telephone rang.
They stared at it. The telephone had never rung before. Jupiter had had it installed less than a week ago when they had definitely decided they would start some kind of business. They planned to pay the charges from the money they made repairing broken items for Mr. Jones. It was listed in Jupiter's name, but of course the listing hadn't been put in the telephone book yet. So far, no one else knew they had it. Yet here it was ringing!
It rang again. Pete gulped. "Well, answer it," he said.
"I will." Jupiter picked it up. "Hello?" he said into the phone. "Hello?"
He held the phone close to a microphone and speaker he had assembled from parts of an old radio. This made it possible for them all to hear what was said. But all they could hear was a curious humming, far off.
"Hello!" he said once more. But there was still no answer, so finally he hung up.
"Probably a wrong number," he stated. "As I was saying -"
The phone rang again.
They stared at it. Jupiter reached for it as if someone was holding on to his arm for dear life.
"Huh-hello?" he said.
They heard the strange humming again, sounding far off and lonesome. Then they heard a voice that seemed to be gargling, as if the speaker hadn't talked in years but was trying hard to say something.
"Stay -" the voice said. Then, as if it were a great effort, as if it were the most tremendous effort imaginable, the voice got out another word.
"- away," it said. "Stay ... away."
Then it died out in a long gasp, and again there was just a weird humming noise.
"Stay away from what?" Jupiter asked the telephone.
But the telephone didn't answer. It just went on humming.
He hung up. For a long moment no one said anything. Then Pete stood up.
"I've got to get home," he said. "I just remembered something I have to attend to."
"Me, too." Bob hopped up. "I'll go with you."
"Possibly Aunt Mathilda would like me to do some errands," Jupiter said, and he got up, too. They practically fell over one another in their eagerness to get out of Headquarters.
The voice on the phone hadn't finished the sentence. But they didn't have any trouble figuring what he - or it, or whatever it was - had been trying to tell them.
Stay away from Terror Castle!

The telephone rang, for the second time that day.
They stared at it.
It rang again. "Well, answer it," Pete said.
"I will." Jupiter picked it up. "Hello?" he said into the phone. "Hello?"
He held the telephone close to the microphone so that Pete could hear what was said, too. They heard a rasping sound.
"Hello!" Jupe said again. There was no answer.
"Maybe it's a wrong number," Pete said.
"I - don't think so," Jupiter said. "Listen!"
Then they heard the strange rasping sound again. The sound was like that of somebody trying to breathe, gasping for air with great difficulty.
The curious breathing sounds changed to a voice that seemed to be strangling, as if the speaker had only a few moments of life left.
"Keep -" the strangling voice said. Then, as if it were the most tremendous effort imaginable, the voice continued.
"Away," it said. "Keep ... away."
Then it became a heavy breathing sound again.
"Keep away from what?" Jupiter asked the telephone.
"My ... cave," the voice said. There was another long gasping sound and then silence.
"Why?" Jupiter asked. "Say, who is this?"
The voice sounded hollow now. "Dead ... men," it said slowly, "tell ... no ... tales!"
There was a long trembling gasp, and then silence.
Jupiter hung up. For a moment, he and Pete sat staring at the phone. Then Pete hopped up.
"I just remembered we're having dinner early tonight," he said. "I'd better get on home."
Jupiter jumped up. "I'll leave, too. Aunt Mathilda might want me to clean up the yard a little."
Quickly both boys bolted from the trailer.
They hadn't had any trouble understanding what the ghostly voice had told them. It was a very simple message.
Keep away from my cave!
Dead men tell no tales!
Old Mr Allen had told them about a dragon entering a cave.
He hadn't mentioned a dead man - or a ghost!