“Yes, about a year ago. He hadn’t stolen anything since he left Europe, and the police thought that he had given up, or perhaps even died. But when the diamonds were stolen we knew at once that Schmidt was the thief. The way it was done, it could have been no one else.”
“The modus operandi, or method of operation is very important,” agreed Jupiter. “That is how most criminals are caught, especially professional thieves. A thief can never really change his way of committing a theft except in minor details.”
“That’s right, Jupiter,” Reston acknowledged. “The theft was obviously the work of Laslo Schmidt, and we realized that he had been simply biding his time. It became clear that he had spent his years in this country establishing a new identity. So now he is actually two men: Schmidt the thief, and some other person who is perfectly normal and above suspicion.”
“And you don’t know what this other identity is,” Bob put in quickly. “It could be anyone around here.”
Reston nodded. “Exactly, Bob. I traced him through the sale of two of the diamonds. First to Reno, Nevada, and then here.”
“Nevada!” Pete and Bob both exclaimed at once.
“Gosh,” Pete added, “we thought you were driving that Nevada car that forced us over the cliff.”
“No, boys,” Reston explained. “I was on my way to Moaning Valley when I saw your bikes at the edge of the pass. I stopped to see what was wrong, and would have rescued you, but then I saw those other people coming and knew you’d be okay. At that time I didn’t want to reveal my presence here. You see, I think Schmidt spotted me in Nevada. I tried to fool him by putting on this eye patch and pasting a false scar on my face before coming to Santa Carla. I’m not sure my disguise was successful, though.”
“That’s why you’ve been sort of hiding?” Bob asked.
“That’s right. I didn’t want Schmidt to know I was still on his trail.”
While Reston had been talking, Jupiter had been staring off into the dark spaces of the cavern and biting his lip. Now an eager gleam came into his eyes.
“The diamonds he stole,” Jupiter said slowly. “There is something special about them, isn’t there, Mr. Reston?”
Reston looked at him in astonishment. “Why, yes, Jupiter, there is. You see, they weren’t stolen from any jewellery company or store. They were taken from a special display at a museum in San Francisco. They — ”
“—are rough diamonds!” Jupiter completed the sentence for him. “They are uncut, exactly as they came from the diamond mine, correct? They are also industrial diamonds.”
“I don’t understand how you know,” Reston said, “but you’re right about their being rough diamonds. Only a few are just industrial stones, though. You see, the display was made up of diamonds from all over the world, just as they came out of the ground. Because they look like ordinary rocks, and because they were in a museum, they were not very well-guarded. Schmidt had no trouble stealing them. Most of them are gemstones, very valuable and just about unidentifiable since they are rough. But how did you know, Jupiter?”
“Because I found a rough diamond here in the cave,” Jupiter said, “and because I think Old Ben and Waldo have found the rest of them!”
“Then the stones really are in the cave!” Reston exclaimed.
Jupiter nodded solemnly. “I think your Laslo Schmidt hid them here right after he stole them. He probably planned to keep them hidden until everyone gave up the chase. Only Old Ben and Waldo, prospecting secretly in the cave as they have probably been doing for years, found them and thought that they had uncovered a diamond mine!”
“But there are no diamond mines in this area,” Reston pointed out.
“No, sir, but Old Ben and Waldo have always believed that there are diamonds here. I remember Mr. Dalton said they have been looking for precious stones as well as gold and silver. The diamonds Schmidt stole look exactly as they would if they had just been dug up, don’t they?”
“Yes, they do,” Reston admitted, “but wouldn’t Ben and Waldo have suspected something odd when they found all the diamonds hidden in one place?”
Jupiter nodded eagerly. “Yes, but I don’t think Old Ben found them that way! We are right on top of the San Andreas Fault here, as you know. The cave is filled with the debris of large earthquakes that occurred some years ago. We haven’t had a large quake for many years, but small ones are always happening.”
“You mean you think there was an earthquake here just recently?” Pete asked.
“Yes, I do. I think that a small earthquake about a month ago disturbed the hiding place of the diamonds. Old Ben and Waldo, digging as usual, found the diamonds scattered in the dirt and thought that they had found a mine!”
“Wow!” Pete exclaimed.
Reston nodded. “Yes, it’s quite possible. However, boys, you must remember that a detective has to consider all possible explanations, and there is another possibility. Old Ben or Waldo may have stolen the diamonds themselves, and are now only recovering them after the earthquake buried them.”
Jupiter reddened. “Of course, I should have considered that.”
“But, Mr. Reston,” Bob said, “Old Ben and Waldo have been here a long time! They’re local characters. They couldn’t have come from Europe only five years ago.”
Reston smiled. “Remember, Bob, that I said Laslo Schmidt is a master of disguise and impersonation! He could be impersonating one of them.”
“Gosh, of course,” Bob agreed.
“However, I think there is only one way to find out,” said Reston. “We’ll go back to that cavern where Ben and Waldo were digging and see if we can find out where they went. But first, I think one of you boys had better go back to the ranch and call the sheriff. We’re going to have evidence to show him.”
Jupiter nodded. “I think Pete had better go.”
Pete’s face fell. “Just when we’re going to finish the case!” he protested.
“Jupiter is right,” Reston said. “Bob’s leg isn’t in good shape, and I want Jupiter with me. Besides, I can see that you’re the fastest, Pete. On a team, each man has to do what he does best.”
Still reluctant, but pleased with the tribute to his athletic prowess, Pete obeyed. He slipped quietly out of the cave, and began to run at a steady pace towards The Crooked-Y ranch house.
Inside the cave, Jupiter, Bob and Sam Reston walked quickly through the tunnels until they stood in front of Old Ben’s secret cavern. Reston moved the boulder, and stepped into the cavern.
The little room was empty. But in the far wall, they found Old Ben and Waldo’s exit tunnel. It was another man-made mine shaft, and it angled sharply upward. With Sam Reston in the lead, his pistol ready, they started through the tunnel. Jupiter marked another trail of chalk question marks.
“We’re heading towards the north ridge of the mountain,” Bob said as they advanced. “That’s where the book says Old Ben and Waldo have their cabin.”
“That is to be expected, Bob,” Jupiter observed. “They opened an old mine shaft close to their cabin so there would be less chance of being observed.”
Reston suddenly stopped. Ahead, the shaft ended in a wall of rocks. Bob noticed footprints on the ground that seemed to go straight into the wall of stones. Reston bent close. He leaned against a boulder and moved it out of the way. Then he moved two more large stones until there was a small passage.
The detective crawled into the passage. For a moment his feet were visible to the boys, and then they vanished. Bob and Jupiter peered into the hole, then quickly scrambled through.
They stood in the clear night behind a thick cover of trees and bushes on the north ridge of Devil Mountain.