“Come on,” said Jupiter, “I want to hear this.”

He pointed diagonally ahead to a clump of eucalyptus trees right by the fence. Their low-hanging branches would give good cover if the boys could get under them unobserved. Cautiously Jupiter wriggled forward, practically on his stomach. Pete and Bob slithered after him. Soon they were safely under the trees, enveloped by darkness and the oily, medicinal smell of the eucalyptus leaves. The boys peered out and found themselves staring at Olsen barely twenty feet away.

A metallic sputter came from Olsen’s walkie-talkie. He bent to speak into it, and this time the boys could hear him clearly.

“Come on over this way,” Hatchet-Face ordered.

His walkie-talkie crackled. “Okay,” came the answer.

A dark figure was making his way slowly across the huge, disorderly pile of scrap. He held a walkie-talkie, too, with its long antenna extended.

The hatchet-faced man spoke. “Any luck yet, Dobbsie?”

The other shook his head as he slowly advanced, peering closely at the scrap metal under his feet. “Not a thing,” he said, his voice filtering through Olsen’s walkie-talkie.

“Stay with it,” Hatchet-Face said. “It could be buried.”

Olsen stooped and tossed an old mudguard aside. It fell with a dull clank. He repeated the action with a bumper and a radiator grill, scrutinised the area closely, and shook his head.

The other man drew closer, also lifting and discarding objects in his path. At last he came close enough to join Olsen. He was dressed like Olsen, in a dark business suit.

Both men pushed down their walkie-talkie antennas. “It’s like looking for a needle in a haystack,” the other man complained wearily.

“I know,” Hatchet-Face said. “But we can’t take the risk of losing it now. It’s too big a haul to let get away.”

“What about the other place?”

“The junkyard? Probably clean, but we’ll have to keep an eye on it. The fat kid may be wise to something. We’ll get back to him later.”

Jupe and his companions exchanged glances. He was the only fat kid they knew of connected with a junkyard. Jupe swallowed. He didn’t like being called fat. And he liked even less the threat in Olsen’s last words.

The other grinned. His face was square and pale, centred by a flat, mashed nose under little beady eyes. “What about the two new ones Hall just got in? Shouldn’t we go for those?”

Olsen shook his head. He reached into his pocket for a scrap of paper and looked closely at it. “Not yet. It would be too risky and our birds might fly away.” He tapped the paper. “The information we got from Dora’s alarm spells it out for us. DOX ROX NOX EX REX BOX. Six X’s. It could be the cable code or else they’re talking about six hundred K’s. That’s about half a million dollars, Dobbsie — not bad, at all. That’s a lot of rocks.”

The beady-eyed man shrugged. “Sure it is, and we might blow the whole deal by waiting. Why don’t we just move in on him?”

Hatchet-Face replaced the paper in his pocket. “We wait,” he said firmly. “He’ll give us an opening. Somebody got careless tonight. If we can find the rocks first, we’ll wrap them both up.”

“Okay. You’re running the show.”

“You bet. I’m going up now to find out if Eastland has his finger in this. He’s desperate for money and maybe he let the gorilla out for his own reasons. Remember, he’d have Hall on the hook for fifty grand if anything were to happen.”

The other grinned and smacked his fists together. “I’d like a crack at Eastland. He ran me off the set.”

Hatchet-Face laughed. “He won’t bother me. Okay, Dobbsie, we check tomorrow same time.”

Olsen waved abruptly and turned away. The other moved off in the opposite direction, across the salvage yard.

Pete nudged Jupe and pointed along the wire fence. The section towards which Olsen was heading had been tampered with. Where earlier it had been erect, it now sagged nearly to the ground.

As they watched, the hatchet-faced man carefully stepped over the lowered wire. He found a metal post and pulled it up straight, raising the wire along with it. That done, he wheeled, dusted his hands, and headed up the slope in the direction of the Hall house. Darkness covered him as he moved into the jungle. His footsteps could be heard for a while longer, and then they faded into silence.

The Three Investigators waited and then slowly got to their feet. The salvage yard was quiet, as if closed down for the night. The beady-eyed man had disappeared from view, too. The boys started back up the hill.

Pete suddenly hissed a warning and they froze.

They heard a stealthy movement in the grass and, as their pulses quickened, the sound of soft footsteps. Peering into the darkness of the jungle, they backed off uncertainly.

A thick, shadowy shape detached itself from a tree and stepped towards them. With hearts leaping, the boys turned and ran. A hidden root caught Jupe’s foot and he fell heavily to the ground. His hand struck something hard and cold. He heard a growl behind him and grasped the hard object as he jumped to his feet. It was a length of metal pipe.

Pete grabbed Jupiter’s arm and started to pull him along. There was an angry bellow from the darkness, and they were suddenly caught in the gleam of a torch.

Heavy footsteps crashed through the undergrowth. Still holding on to his weapon, Jupe fled, propelled by Pete. Bob was just ahead of them, his feet flying across the slope. He lost his footing and as he fell, Jupe and Pete charged into him, carrying him up and along.

The torch beam stabbed at them again, and they heard a harsh voice yelling for them to stop. Instead, they ran faster.

Panting noisily, following Pete’s unerring sense of direction, the boys cut across the hillside. They burst out of the jungle on to the road to the Hall house. Just ahead was the gleaming Rolls-Royce. As they ran for it, its headlights flicked on.

Jupiter flung the door open and threw himself inside.

“Quick! Step on it, Worthington!”

Bob and Pete tumbled in beside him as the tall chauffeur calmly answered, “Very good, Master Jones.” The motor was already purring smoothly, and deftly he wheeled the big car round.

As they headed back for the exit gate, a man broke out of the jungle and leaped for the car. Worthington swerved instantly, and they had a brief glance at the contorted face of the man. He raised his fist and ran after them.

“Wow!” breathed Pete. “That’s Bo Jenkins, the new animal helper.”

Looking back through the glass, they saw Jenkins stop and shake his huge fist in a threatening gesture. It carried so much menace that they instinctively slumped low in the back seat of the car, although they were already safely away from their pursuer.

Pete jumped out as Worthington slowed down at the gate. He opened it, and after the car glided through, swung it closed again. Then Pete leaped back in and sat back, slowly shaking his head.

“What was that all about?” he asked.

Jupe had no reply. He could only scowl, puzzled as he gripped the weapon he had not used.

Pete, Bob, and Jupiter stood by the gates to The Jones Salvage Yard. Worthington had brought them back safely and had been thanked and dismissed.

“It’s late,” Jupiter said, “but I suggest we have a quick meeting. We have to put down what happened this evening between that man Olsen and the other, Dobbsie. It might contain clues we will need for solving this mystery.”

He led the way swiftly into Headquarters, tossing the metal bar he had found at Jungle Land on to his work-bench before stooping to enter Tunnel Two. Inside, the boys clustered around the office desk, and Bob drew out his notebook.

“I take it we can skip the last part with that big guy Jenkins chasing us,” said Bob. “There wasn’t any mystery about that — he was just plain mad.”