“Aaaaaahhhhhhhhh — oooo — ”
But this time the spooky sound stopped before it was finished. Old Ben had rolled a large boulder into the opening, using the bar as a lever. With the rock in place there was no trace of the opening. And the moaning stopped abruptly!
“Gosh, Jupe,” Pete said. “That’s what you meant! No one could tell there was a hole in that wall.”
The large boulder fitted tightly into the gap as if it had always been there.
“Right,” Jupiter whispered, “and the blocking of the hole stops the moaning right away. That bell must be the signal from whoever is watching up on the mountain. I think it means someone is coming into the cave.”
“Maybe Bob got scared and went for help,” Pete said. “I hope.”
Old Ben was pacing up and down in the mine shaft, muttering to himself. He didn’t even glance towards the rocks where the boys were hiding. Then, suddenly, the old man switched off his lantern. For a moment there was no sound in the dark mine shaft; then the boys heard the pacing and muttering begin again. They waited tensely in their hiding place.
In the darkness, Pete tried to sort out everything he had learned that evening. There were still questions he wanted to ask Jupiter, but Pete thought he understood most of the answers to the mystery of Moaning Valley.
Old Ben was digging secretly in the cave. Up on the mountain someone was on guard. The moaning sound was produced by the wind blowing through the narrow opening of the prospector’s secret cavern. When someone came to the cave, the guard signalled with the bell and Old Ben closed up the hole. The moaning sound stopped and there was no clue to what caused the moaning.
Pete felt quite pleased with himself for figuring it all out. He had answered all the questions himself… or had he? Who, for instance, was the fake El Diablo who had captured them? And how did he fit into the puzzle? Was that what Jupe had been referring to when he said something was still unexplained?
“Pete!” Jupiter’s voice whispered in his ear. “Someone is coming!”
Pete was so startled he almost lost his balance. He grabbed at the big rock in front of him, and a small stone rolled to the ground. Had Old Ben heard the noise? Pete held his breath.
A moment later he saw a bobbing light approaching.
“Waldo?” Old Ben’s voice said from somewhere nearby.
“Yup,” a voice replied from behind the bobbing light. “They’s two of ’em coming in the cave, Ben. We best skedaddle.”
Old Ben’s lantern came on, and Jupiter and Pete could see the tall, thin figure of Waldo Turner. The boys crouched as low behind the rocks as they could get. The two old men stood less than ten feet from them now.
“You sure they’re comin’ in?” Old Ben asked.
“I’m sure. Too dang many people foolin’ around this cave the last couple days,” Waldo replied.
“Jumping bobcats!” Old Ben exclaimed. “And I figure not more’n a few more days’ work ’fore we’re finished. Well, no sense gettin’ careless now. We better get on out.”
“We better,” Waldo agreed.
It was clear that Waldo Turner was the man on watch on top of Devil Mountain. After giving the alarm, he had come down by some secret passage from the top.
The boys watched the two old prospectors move the boulder away from the hole, pass quickly through, and lever the rock back into the hole from the inside. Then there was silence in the pitch-black mine shaft.
“Where did they go, Jupe?” Pete whispered.
“There must be an exit from that cavern to the outside of the mountain. There would have to be. The wind wouldn’t be able to make that moaning sound if it couldn’t blow through from the other side. It’s probably one of those old mine shafts that are supposed to be sealed up. I’ll bet Old Ben and Waldo knew just where those shafts were and unsealed one.”
“How come the sheriff and Mr. Dalton don’t know it’s there?” Pete asked.
“It’s probably concealed,” guessed Jupiter. “There has to be another entrance up high on the mountain, too, for Waldo to get down here so fast. There are probably quite a few hidden entrances. However, I think it’s time we went for help.”
“Let’s go!” Pete agreed fervently.
The boys switched on their flashlights and walked rapidly back along the mine shaft. By retracing their steps, they soon reached the first large cavern they had entered the previous night.
As they hurried towards the tunnel that would lead them outside, two figures leaped out of the shadows. Strong hands closed on Pete’s arm.
“Got you!” a harsh voice grunted.
Pete gulped in fright as his light shone up into the long, scarred face of the man with the eye patch.
“Run, Jupe!” Pete cried.
At the same instant, a flashlight was suddenly beamed on Jupiter by the second man.
16
A Tale of Diamonds
“Just stay where you are,” the man with the eye patch commanded. “If you start running around in the dark you’ll get hurt.”
Jupiter braved it out. “I doubt that you would care if I were hurt. I suggest you let us go. We have friends here.”
The man laughed. “Spunky, aren’t you?… Why don’t you come over here where we can have a talk.”
“Don’t, Jupe!” Pete cried.
And then a familiar voice spoke from behind the flashlight of the second man.
“It’s okay, fellows. Mr. Reston is a detective!”
The voice was Bob’s and his face was one big grin when he came out into the light and saw the astonished looks of his partners.
“I started for the ranch to get help after I saw that the man in the Nevada car was going into the cave,” Bob explained. He went on to describe his sudden hunch that Old Ben and Waldo were involved in the mystery of Moaning Valley. “After the Nevada car passed me I was scared and ran right into Mr. Reston here.”
“Sam Reston,” the man with the eye patch, introduced himself. “I’m a detective, boys, working for an insurance company. When your friend here told me of his suspicions about Old Ben, I decided to come back to the cave with him instead of going all the way to the ranch for help.”
“Mr. Reston thought you might need help right away,” Bob explained.
“I did,” Reston said, “because the man I’m after is very dangerous. Bob and I tried to get into the cave unseen. It took us some time, and I think we were seen anyway.”
“You were, Mr. Reston,” Jupiter said, suddenly recovering his voice. The First Investigator told Bob and Mr. Reston about everything he and Pete had seen in the cave.
Reston nodded. “I was afraid we’d been spotted. But they can’t have gone far, and that bag you saw probably contains the diamonds I’m after.”
“What diamonds?” Pete burst out.
“That’s the job I’m on, boys,” Reston explained. “I’m trying to find a very clever jewel thief who stole a fortune in diamonds. His name is Laslo Schmidt, and he is known all over Europe. I followed his trail here to Santa Carla just a week ago. Then I heard about Moaning Valley and El Diablo’s Cave, and I had the idea that the cave would be a good place for Schmidt to hide. Only I haven’t found a trace of him.”
“Gosh,” Pete said, “if you followed his trail here, why couldn’t you spot him?”
“Because I have no idea what he looks like now,” Reston told them. “You see, boys, about five years ago Schmidt left Europe in a hurry. The International Police, Interpol, learned that he had come to America and assumed a new identity. But that was all they could find out. Schmidt is a master of disguise and impersonation. He could act the part of almost anyone and make you believe it.”
Jupiter had his faraway thoughtful expression. “And he stole some diamonds insured by your company, Mr. Reston?”