“I’d say more responsibly than most adults,” Reston said. “And they seemed to have solved our mystery, even if the thief did get away.”

Mrs. Dalton smiled. “I’d say they have turned out to be pretty good investigators.”

“They did solve the case at that,” the sheriff went on. “It’s too bad the thief got away, but we’ll nab him yet.”

“Please, sir!” Jupiter cried.

Everyone stared at the First Investigator in surprise.

“I’m not sure the thief has got away yet,” Jupiter insisted eagerly, “or that he’s even trying to.”

“What do you mean, son?” asked the sheriff.

“Can you tell me where everyone else is, sir?” Jupiter asked quietly.

“Everyone else? You mean the people from the ranch? Why, they’re all out looking for you boys,” the sheriff said. “Dalton and his men are down on the beach, and Luke Hardin and Professor Walsh are with some other men on the far side of Devil Mountain.”

“Where were you going to meet later?” Jupiter asked.

“At the ranch house,” replied the sheriff.

“Then I suggest we all go to the ranch house quickly,” Jupiter said firmly.

The sheriff frowned. “Now see here, boy, if you have anything on your mind you better tell us.”

Jupiter shook his head. “There isn’t time, sir. It would take too long to explain, and we must catch him before he can dispose of the evidence.”

“Better listen to the boy, Sheriff,” Sam Reston advised. “I’ve learned from experience that he knows what he’s talking about.”

“All, right then,” the sheriff agreed. “Come on, boys, you can ride with us.”

Jupiter got up behind the sheriff on his horse, and Bob and Pete rode with two deputies who had been waiting outside on horseback. It was a wild ride across the rugged terrain. The boys hung on desperately, as they jounced and swayed along, unable to see where they were going.

But when they reached the house they saw no sign of life. There was only a dim light in the kitchen window.

“Well, son,” the sheriff said to Jupiter, who clung behind him, “who did you expect to find here?”

Jupiter bit his lip in the dark. “I’m sure he will come back. We must have beaten him here. He has to pretend to search for us for a while, at least. I suggest we all dismount and wait in the dark.”

“We’ll dismount all right,” the sheriff agreed, “but I want to know what this is all about.”

The sheriff swung down, and helped Jupiter to the ground. A moment later Sam Reston pulled up in his car.

“Now, son,” the sheriff said firmly, “you tell me what this wild goose chase is about.”

“Well, sir,” Jupiter explained, “I remembered some things the bandit said to us when we were in the cabin. I put them together with some facts, and… ”

A man suddenly came limping towards them from the side of the ranch house.

“Well, I see you located them, Sheriff,” Professor Walsh said. “Good work. You boys had quite a busy night, eh?”

The professor smiled from behind his thick glasses, and touched his left leg. “Took a spill, I’m afraid. Had to come back and bandage up a nasty cut on my leg.”

“You’re just in time, Professor,” the sheriff said. “Young Jones here is about to tell us a story.”

Jupiter’s voice was calm. “That won’t be necessary now, Sheriff. I suggest you search Professor Walsh for the diamonds. I don’t believe he would have abandoned them again, especially since he is sure we don’t suspect that he is really Laslo Schmidt.”

“Schmidt!” Sam Reston cried, staring at the professor.

“I think the diamonds will be under the bandage,” Jupiter added.

With a cry, Professor Walsh turned and ran. In a second everyone was in pursuit. All except the boys and Mrs. Dalton. They turned and stared at Jupiter.

The First Investigator just stood there and grinned.

“So, young Master Jones, the diamonds were indeed found under the bandage on Professor Walsh’s leg?” Alfred Hitchcock asked.

“Yes, sir,” Jupiter said. “They captured the professor just as he reached his car, the one with the Nevada licence. It turned out that he had two cars. The one with the Nevada licence he kept hidden in a concealed gully in Moaning Valley. The El Diablo costume and rubber mask were in the car. He had not disposed of them because he was confident that no one had guessed he was Laslo Schmidt.”

“Ah, the over-confidence of the master criminal,” the famous director observed solemnly. “Well done, lads.”

It was a week after the capture of Professor Walsh, alias Laslo Schmidt. The boys had just returned home after a well-earned week’s vacation on The Crooked-Y Ranch, swimming, riding and learning about ranch operations. Now they sat in the office of the famous motion picture director and reported on The Mystery of the Moaning Cave from Bob’s notes.

“I believe I understand the secret of the cave’s moaning,” Mr. Hitchcock continued, “and the activities of Old Ben and Waldo. Incidentally, what happened to those two old rascals in the end?”

Bob grinned. “The sheriff finally decided that they hadn’t really had a chance to be guilty of any wrongdoing. He preferred to believe that they would eventually have had sense enough to turn in the diamonds. Mr. and Mrs. Dalton even forgave them for scaring everyone.”

Mr. Hitchcock nodded behind his big desk, “I see. Yes, I suppose they were merely carried away by their dreams of a rich strike.”

“Then you’ll introduce our report on this case, sir?” Pete put in eagerly.

“Wait!” Mr. Hitchcock thundered. “I have not yet said that. I have agreed to introduce any of your adventures that are worthy of my attention, and I understand the matters of the moaning and the old prospectors. However, I have not yet learned how young Jones came to his sudden conclusion that El Diablo and Professor Walsh were really Laslo Schmidt.”

Jupiter leaned forward in his chair. “Well, sir, I began to wonder about Professor Walsh possibly being the false El Diablo. Then it became clear that he was the most logical person to be Laslo Schmidt. He was the only real stranger at The Crooked-Y, and his past history was the most easily falsified.”

Mr. Hitchcock nodded. “I see that. He was in the area only for a year, and it is easier to pretend to be a professor than an ex-rodeo rider or a ranch foreman. But what led you to consider him at all?”

Jupiter frowned. “Actually, sir, I should have considered him sooner. But I admit it did not strike me until we were all captured in Old Ben’s cabin. It was what he said after he tied us up that revealed it all to me.”

Mr. Hitchcock leafed through Bob’s notes. “He doesn’t appear to have said much,” the director finally observed.

“Not much, but enough,” said Jupiter. “First, he mentioned having seen our scuba tanks. Only someone at the ranch could have seen those tanks. Second, there was his voice. Although it was muffled and disguised so that we could not recognize it by its sound, he could not disguise his pattern of speech. And when I thought about my other clues, I suddenly realized the pattern was obviously that of Professor Walsh.”

Mr. Hitchcock’s eyes sparkled. “I see. Yes, the speech pattern of a person can be a real give-away.”

“Then,” Jupiter went on, “he said that he became nervous when he realized that Reston was close behind him again. That gave me two clues. First, that the false El Diablo knew who Mr. Reston was, and second that he knew that Mr. Reston was getting close to him!”

“Of course!” Mr. Hitchcock exclaimed. “Reston had told you that Laslo Schmidt knew him by sight. And no one had seen Reston except you boys. You described Reston to the others. So it was clear that your false El Diablo was a man who had recognized Reston from your description, even with the addition of the eye patch and the scar.”