“We’ll omit Bo Jenkins for the time being,” Jupe agreed. “I imagine he was merely patrolling the property. Perhaps he was within his rights to chase off trespassers who might disturb the animals.”

“I don’t know about that,” Pete protested. “We weren’t exactly strangers there. He saw us earlier at the cage when Mr. Hall and Doc Dawson brought the escaped gorilla back. He could have acted a lot nicer about it, if you want my opinion.”

“True,” Jupe said, “but it was dark. Perhaps he didn’t see us clearly, and thought we were just some kids who had broken in. I’m inclined to give Bo Jenkins the benefit of the doubt. I suggest we ignore him and get to the discussion between Mr. Olsen and Mr. Dobbsie.”

While Bob scribbled furiously, the boys reconstructed the conversation they had overheard and discussed what it might mean.

“What could be right under their feet?” asked Bob.

“It must be small,” Pete said. “Because he also said it was like looking for a needle in a haystack.”

“Not necessarily small,” Jupe said. “It would be difficult to find something that looked like all the other junk in that heap.”

“Like what?” asked Bob.

“I don’t know,” Jupe said. “But we have clues. Read back that part about rocks and X’s, Bob.”

“Okay,” Bob said. “It went something like this: ‘The information from Dora’s alarm tells us. DOX ROX NOX EX REX BOX.’ I assume all those words end in X because of the next bit. ‘Six X’s. Could be the code or six hundred K’s. That’s half a million dollars, Dobbsie. That’s a lot of rocks.’ ”

“More or less correct, I believe,” said Jupe. “Olsen also used the word ‘cable’. We don’t know who Dora is or what her alarm is, but Dora’s message sounds like a cable. It’s typical of what is called cablese — all the words are short and only important words are included. And, like many cables, this one seems to be in code. As a rule, parties who want to keep their business transactions secret establish a private code or cipher. Usually there’s a key letter or word that lets them decipher each other’s messages easily.”

“Well, we don’t have the key to the code,” said Pete.

“I don’t think we need one,” said Jupe. “All those words probably end in X, as Bob said. But most of those words translate easily into plain English. The message can be read DOCKS ROCKS KNOCKS EX WRECKS BOX.” He printed the decoded message for them on Bob’s pad.

“Great,” said Pete. “What’s that supposed to mean?”

“I’m not sure,” said Jupe, “but I’m getting an idea.” He straightened up excitedly. “I think ROCKS is the important word. Olsen said something was half a million dollars, and then he said that was a lot of rocks. Does that suggest anything to you?”

“Half a million dollars worth of rocks?” asked Pete. “Rocks out of the ground? How’s that possible? I mean, who’d want it?”

“ ‘Rocks’ has another meaning, Pete,” Jupe said. “It’s also slang for ‘money’. Olsen and Dobbsie are looking for money! Half a million dollars! My guess is that Olsen and Dobbsie are involved in some crooked scheme. They sound like gangsters, and that much money sounds like somebody’s loot!”

“That’s quite a guess,” said Bob dubiously. “But even if that’s true, what’s the rest of the message supposed to mean?”

Jupe frowned. “I don’t know, Bob. Apparently it tells where to find the money. Maybe the rest of the conversation will give us some clues.”

“What about that part about wrapping them both up?” Pete asked. “Who’s he talking about?”

Bob read from his notes. “ ‘If we can find the rocks first, we’ll wrap them both up.’ ”

Jupe shook his head. “They spoke about one man first. They said, ‘Why don’t we move in on him?’ Then later Hatchet-Face said, ‘He’ll give us an opening. Somebody got careless tonight.’ ”

“Who?” asked Pete.

Bob looked over his notes. “If being careless refers to letting the gorilla out, they think Eastland might have done it.”

Jupe scowled. “I don’t see why he would take such a risk. It’s true that according to the agreement Jim Hall would have to pay Eastland fifty thousand dollars as forfeit for an accident. But I don’t think Eastland would be foolish enough to take such a chance. That gorilla was dangerous! I’d sooner believe that Hank Morton was being spiteful again.”

“Fine, but that has nothing to do with rocks,” said Bob. “We’re not getting anywhere.”

Jupe tapped his fingers on the desk and thought awhile. “We’re forgetting the first thing we ever learned about Olsen,” he said finally. “He came here to the junkyard and wanted to buy cages. Then tonight he seemed to refer to me and the cages.” Jupe winced as he remembered Olsen’s calling him “the fat kid”.

“Maybe he thinks he’ll find his rocks in cages,” said Pete sarcastically.

“Don’t laugh,” said Jupe. “Look! BOX in the cable might mean cage! WRECKS BOX means pull apart the cage and you’ll find the money!”

“Your cages are already wrecked,” objected Pete, “and Olsen didn’t seem to think they were very valuable. He only offered you twenty dollars.”

“True, true,” said Jupe. “I can’t explain that. But perhaps Olsen’s really looking for another cage.”

“Sure. In the scrap yard. Blending right in with the cars,” said Pete. “I think we’re all tired and just going round in circles.”

Jupe stood up and stretched. “You’re probably right, Pete. I suggest we quit for tonight. We haven’t come to any definite conclusions — but at least we’re sure of one thing.”

“What’s that?” asked Bob.

“We’ve got a mystery to solve,” said Jupe with satisfaction.

The next morning Bob came downstairs to breakfast more puzzled than ever. So much had happened the day before, and so little of it made any sense. He wondered if Jupiter wasn’t grasping at straws in deducing the meaning of that crazy code.

Bob said good morning to his father, who grunted a reply from behind the morning newspaper. He was still on his first cup of coffee and obviously wasn’t ready to talk to anyone yet. Bob looked around for something to read himself. He had read all the cereal boxes, so he turned to the stack of out-of-town newspapers lying on a nearby bookcase. His father, a newspaperman, frequently brought home papers from other parts of the country. He had explained to Bob that no one newspaper could carry all the news, and that he liked to see what stories other papers considered newsworthy.

Bob leafed idly through a paper, reading the comics and checking the headlines. He picked up another, and an article caught his eye. It was a UPI dispatch from Koster, South Africa. It read:

With a whoop belying his 79 years, Pieter Bester leaped into the air, snatched his claim certificate, and took off running.

While 3,000 spectators cheered, he opened what could be the last official South African diamond rush, as 165 prospectors we returned loose Wednesday on the Swartrand alluvial diamond field.

Veteran prospector Hendrik Swanpoel, 72, who discovered the diamond field, had his usual luck. While staking out the first of his claims on the site, he unearthed a 48.12-carat diamond which he sold later for $42,000.

“I don’t want to discourage anybody,” Swanpoel said with a grin,“but I’ve already got most of the good stuff.”

The article went on to give details of the government-sponsored diamond rush. The region was 75 miles northwest of Johannesburg, once known as the “Land of the Diamonds”. In the uproarious boom days of 1927 and 1928, the article continued, 150,000 diggers scooped $28 million worth of high-quality gems from the Grasfontein and Bakerville diggings 50 miles west. The rules were, hopeful prospectors had their names put into a hat, and only the lucky ones whose names were drawn were permitted to the starting line. Each one was allowed three 45-square-yard claims. Veterans of earlier rushes hired local athletes for the sprint, or after careful coaching, had their sons run for them.