“There’s nae a mon to do decent work these days,” the Scotsman grumbled. “Kept me waiting a’ afternoon for the repairs!”

“Rory,” Mrs. Gunn said, “do you remember anything built here out of stone? A whole ton of stone? Aside from the house and shed?”

“Stone?” Rory frowned. “A ton o’ it?”

Bob and Pete repeated what Mr. Ortega had told them.

“I dinna recall anything,” Rory said. “Ye say the quarry might tell ye more o’ the size ‘n shape o’ the stones?”

Bob nodded. “But it’s getting late. We’d never make it on our bikes before dark.”

“Then I’ll drive ye there,” Rory said. “I ha’ another trip I could make in that direction. I’ll drop ye on my way, and ye can ride yer bikes back.”

Bob put his bike in the boot of the Ford, and Pete squeezed his in along the back seat. They jumped in the front beside Rory and drove off.

There was still light when they reached the entrance to the old quarry. Rory dropped them and their bikes, and drove away.

The old quarry was a deep, vast pit at least two hundred yards across, with some water at the bottom. Stone jutted everywhere, glowing in the sunset. The whole mountainside had been gouged out in a series of encircling terraces, like steps. Far across, the quarry opened out away from the mountain and was only a few terraces deep. Here, near the bottom, a sturdy shack stood on a stone terrace that gave directly on to a low shoulder of the mountain. There was light in the shack, and a truck parked by it.

“The caretaker’s still here!” Pete said.

They scrambled down into the quarry and made their way along a terrace. They were less than halfway to the shack when the light went out. A man came out and got into the truck.

They shouted, “Hey!.. Mister!.. ”

The man was too far away, and the truck engine drowned their voices. They ran, but the truck drove off on a back road and was gone. When they reached the shack, it was dark and padlocked.

“Too late,” Pete moaned.

Bob studied the shack. Its four windows were shuttered and locked outside by heavy boards in slots.” Maybe we can get in and find the records ourselves. Mr. Ortega knows we’re here.”

Pete unbarred a shutter. “Bob! This window’s not locked!”

“We’re in luck,” Bob said. “Come on.”

They climbed inside. The shack was an office with old wooden files and furniture. Pete found a cabinet labelled “1870–1900”. He opened it, flipped through the files, and took out a folder marked “1872”. He carried it to a desk. Bob leaned over his shoulder.

Light footsteps sounded outside the shack.

“What’s that?” Bob whirled.

The open shutter banged closed. They heard the board slide in place to lock it. Footsteps hurried away.

They were prisoners!

The late sun slanted across the ragged opening in the hatch. Jupiter and Cluny had shouted themselves hoarse. Now they sat against the dank wall at the upper end of the barge and watched the tide rising steadily towards them.

“How long do you think we have, Jupiter?” Cluny said quietly.

“Perhaps two hours more,” Jupiter said. “Someone will find us soon.”

“No one’s heard us yet,” Cluny said in a low voice.

“They will. Hans must have missed us long ago.”

“But he doesn’t know we’re in this barge. He’ll never look here!”

“In a few minutes we’ll start yelling again. Someone will hear us.”

“Sure, of course they will,” Cluny said doubtfully.

But after a few more minutes, Jupiter didn’t start to shout. Instead, his eyes seemed to stare at something.

“Cluny,” the First Investigator said, “that locker over there. It’s attached to the wall, but maybe we can pry it loose. The wood looks rotten.”

Cluny shook his head. “It’s too low to climb on and reach the hatch, Jupiter.”

“Not to climb on, to float on!” Jupiter said. “If we can get it loose, and it floats, we could hang on to it and float up with the tide!”

They both jumped up and sloshed through the rising water to the locker. It was built into the side of the hold and nailed to the floor. The boys looked about for anything to pry the locker up with.

A heavy tread sounded on the deck above. A slow step, as if wary and careful not to be heard.

“Jupiter!” Cluny cried, “someone’s up?”

“Shhhhh!” Jupiter warned. “No way of knowing who it is, Cluny. We haven’t been yelling for a while. No one could have heard us and come looking.”

Cluny nodded nervously. Both boys held their breath and listened. The heavy tread moved on cautiously across the deck towards the broken boards of the hatch. Then the steps stopped. There was a silence.

“Jupiter?” a deep voice called down. “Cluny?”

It was Hans!

“Hans!” Jupiter yelled. “Down here!”

The boys waded over to stand under the jagged opening in the hatch.

“Get us out of here!” Cluny called up.

“I get you out. Wait,” Hans said from above.

They heard him walk across the deck, and then there was a ripping of wood. Moments later the ladder from the side of the barge was lowered down. Jupe and Cluny scrambled up to the deck.

“Boy,” Cluny said, “are we glad to see you, Hans!”

“I look everywhere for you when you are missing from store,” Hans said solemnly. “You should not go off without me.”

“How did you find us?” Jupiter asked.

“I look through streets, ice cream places, everywhere,” Hans said. “When I go back to chandler shop, a boy is there who tells me he saw you on barge so, I come here.”

“A boy saw us?” Jupiter said, frowning.

“Why didn’t he help us himself, then?” Cluny wondered.

“Yes,” Jupiter said thoughtfully. “Is he still at the shop?”

“No, he has left. He showed me barge, and ran off,” Hans said. “I forgot. Mr. Wright have a message for you. He went to talk to his father, very old man. Old Mr. Wright says no way to tell what Angus Gunn bought in 1872, but there is one way back at Gunn Lodge.”

“What way?” Jupiter asked eagerly.

“Old man say all things sold from store in those days have brass plate on them with name of Wright and Sons,” Hans said. “You must look for brass plate on something.”

“Jupiter,” Cluny urged, “let’s get home and look!”

“And fast,” Jupiter said. “I forgot something, too. Stebbins knows where Pete and Bob went! They may be in danger!”

Christmas tree lights were shining through the windows of the lodge into the early night as Hans parked the truck in the drive. Cluny and Jupiter jumped out and ran inside. Hans followed more slowly, and went to phone Uncle Titus and report. Mrs. Gunn was standing in the living-room. She was alone with a roaring fire against the night chill.

“Mum!” Cluny blurted out as they ran in. “Do we have anything with a brass plate on it marked ‘Wright and Sons’?” He told her what they’d learned in Santa Barbara.

“You couldn’t find out what old Angus bought?” Mrs. Gunn said, knitting her brows. “A brass plate? Well, many of Angus’s old things have brass plates — it was common in those days. But I don’t recall anything labelled ‘Wright and Sons’.”

“Think, Mum, please!” Cluny urged.

Jupiter asked, “Have Bob and Pete come back?”

“Yes. They returned here to tell me about old Angus buying a ton of granite stones from the Ortegas,” Mrs. Gunn said. “But they didn’t know what kind of stone, or what size and shape, so Rory drove them to the old Ortega quarry, and then went off on some errand. But — ”

“They’re not back yet?” Jupiter said, and glanced at the grandfather clock. It was almost seven o’clock.

“No, and neither is Rory,” Mrs. Gunn said. “But — ”

A strange sound came suddenly through the night. From somewhere outside, behind the house, far away. Hans came into the large living-room and stopped to listen with the others.

It was a sound like distant hammering. With a hollow ring, like metal against stone.