“There!” Mrs. Gunn said. “That’s what I’ve been trying to, tell you, boys. I’ve been hearing that sound in the night for over an hour. It frightens me. What could it be?”

“Sounds like someone knocking down a wall,” Hans said.

“A wall? But no one lives that close to us. There’s nothing in that direction except?” Mrs. Gunn stopped.

“Except what, Mum?” Cluny asked. “I don’t know anything out that way.”

“Perhaps you’ve never seen it. There’s an old smokehouse out back. It hasn’t been used since your father was a boy. I’d forgotten all about it.”

“A smokehouse?” Jupiter said. “A stone smokehouse?”

“Why, I suppose it could be stone. It was covered with vines when I first saw it, and I never looked closely.”

“Hans!” Jupiter cried. “Get the lantern from the truck.”

Hans got the electric lantern, and Mrs. Gunn led them back through the brush along an old, overgrown path. The December night was cold for Southern California. The path went on for almost half a mile, finally passing an old wooden cabin.

“A worker’s cabin from Grandfather Gunn’s day,” Mrs. Gunn explained. “That’s why the smokehouse was out here.”

“Did old Angus build the smokehouse, ma’am?” Jupiter asked.

“I’m not sure. I rather thought Grandfather Gunn did — Angus’s son.” She peered into the dark. “It should be just about here.”

The sound of hammering had ceased. Mrs. Gunn led the others off the path into the heavy brush — brush that was all torn and trampled. They pushed through to the smokehouse — and found nothing but a pile of stones!

“Someone’s knocked it down!” Mrs. Gunn said.

“Looking for the treasure!” Cluny exclaimed.

“I suppose we have Stebbins to thank for this,” said Jupiter. “Maybe Java Jim, too. Both of them could have returned from Santa Barbara hours ago. Though how they could have known about this smokehouse…?”

Hans picked up a sledge hammer. “Handle is still warm from hands.”

They listened hard, but there was no sound in the night. Jupiter examined the remains of the smokehouse closely in the light of the lantern.

“The walls were apparently solid stone,” he said slowly. “And from the looks of the firebrick inside, I don’t think anything was hidden inside the firebox. Spiders all over, too.” He looked all around. “No sign of anything dragged off.”

Cluny was pawing among the scattered stones. “Jupe! Here’s a stone with writing on it!”

Hans carried the lantern over. Jupiter brushed dirt away from the stone and read, “C. Gunn, 1883.”

“Grandfather Gunn — His name was Cluny, too,” Mrs. Gunn said.

Jupiter grinned. “Then old Angus didn’t build the smokehouse. The treasure couldn’t have been in it. Let’s go back to the house.”

When they reached the lodge, Professor Shay’s station wagon was parked in front next to the truck. The professor himself was shivering on the steps, blue from cold in his light suit.

“Too cold for California,” the professor said, and then grinned. “I came to see what you found out today, boys. Tell me now, quickly.”

In the warm living-room with its roaring fire and Christmas tree, Jupiter told the professor what they had learned in Santa Barbara.

“A brass plate? And Java Jim and Stebbins were both there?” The professor pondered. “Have you found the brass plate here?”

“Not yet, sir,” Cluny said. “We haven’t really looked.”

“We’re waiting for Bob and Pete,” Jupiter explained. He related Bob and Pete’s trip to the Ortega yard and the quarry, and looked uneasily at the clock. “Rory drove them, but… Wait, here they are now!”

The Ford drove up outside. Rory got out and strode into the house rubbing his hands. He was alone. “Where are Bob and Pete?” Mrs. Gunn wanted to know.

“Where I left them at the quarry, I’ve nae doubt,” Rory snapped. He looked at Cluny. “And what did ye find on yer wild-goose chase to Santa Barbara?”

Cluny told him hurriedly. “We haven’t looked for the brass plate here yet because Bob and Pete aren’t back, and because someone knocked down the old smokehouse at the back.”

“Smokehouse?” Rory scowled. “Ay, I’d forgot about that.” Now Rory looked at the clock. “Those boys aren’t back yet? They should ha’ been back o’er an hour ago.”

“A stone smokehouse?” Professor Shay said alarmed. “But how would someone know about Old Angus’s load of stones unless — ”

“They talked to Pete and Bob,” Cluny said.

“Or visited the Ortega yard,” Jupiter added. He explained how he had tipped off Stebbins. “What worries me now,” he went on grimly, “is that Stebbins and Java Jim could have learned about the old quarry, too. One of them might have followed Pete and Bob there!”

“What!” Professor Shay started for the door. “Then Bob and Pete may be in trouble, boys — even hurt somewhere! Hurry!”

The men and boys ran to the cars.

The old quarry gleamed faintly silver in the cold starlight, its depths fading into bottomless dark. They parked at the entrance where Rory had left Bob and Pete. There was no light anywhere in the quarry.

“Look for some trail!” Jupiter said.

They fanned out at the top of the quarry. Rory soon found the bikes.

“Just where I left ‘em,” the Scotsman said grimly. “They must ha’ gone down into the quarry. Anywhere else, they’d ha’ taken ‘em.”

Carefully they all clambered down into the quarry. Their flashlights made the terraces look like some giant’s stairs. The water in the bottom eerily reflected the flashlight beams. Professor Shay looked at the dank water far below.

“If they slipped,” the professor said with a shudder. “All the way down—?”

“Don’t even talk about it. Professor,” Cluny quavered.

Jupiter looked along the high stone sides of the terraces for chalked question-mark signs. There were none he could see.

“If they were being followed,” Jupiter said, “they didn’t know it. If they had, they would have left question-mark signs to show me their escape route. We always carry our chalk.”

“I’m not sure that’s good, Jupiter,” Professor Shay said. “It could mean they were taken by surprise.”

No one said anything to that grim thought. In silence, they continued on along a terrace halfway down the old quarry. They played their flashlights and lanterns up and down. All they saw were the stone terraces, twisted old trees clinging to the walls in crevices, and piles of fallen rock.

Small animals scurried in the dark, and twice snakes slithered across their path and under piles of stone. Far off coyotes bayed. Some large bird flew heavily through the trees up at the rim of the quarry. A hunting bird, a horned owl, searching for prey.

Still there was no sign of Bob or Pete, and no sounds in the night except the animals. They had almost completely circled the quarry to the far side when they heard the sudden noise!

“Listen!” Hans whispered.

Something metal had jangled not far ahead.

“Can you see?” Cluny whispered.

“No,” Professor Shay muttered.

Wood scraped against wood and metal.

“There!” Jupiter exclaimed softly. “A shack is down there!”

In his excitement his voice rose higher than he had intended. There was a clatter down by the shack, and someone ran. Rory shone his flashlight.

The beam picked out a thin figure running towards a small car parked near the shack.

“It’s Stebbins!” Professor Shay cried. “Stop him this time!”

“Bob! Pete!” Jupiter called.

“Head him off, ye fools!” Rory raged.

“Stebbins! Halt!” Professor Shay yelled.

The slender young man reached his green Volkswagen, jumped in, and roared off down a back dirt road before they could even reach the dark shack. “He escaped!” Professor Shay cried bitterly. “The villain!”

Jupiter wasn’t worried about Stebbins. “But where are Bob and Pete? What’s he done to them?”