“Hey, neat!” Benny cried after he squeezed inside. “This is like a skinny doorway instead of a hole in the ground.”

  “I’m just going to tie this bandana to a branch outside,” Jessie said before joining the others. “Just in case. We won’t go in too far since we don’t have any of our caving equipment with us.”

  “Except for one flashlight,” Henry said, patting his backpack.

  The Aldens found themselves inside a large cave with a high ceiling and plenty of space to move around. Enough light came in from the entrance, so no one was too worried about getting lost.

  “There’s a passageway that goes off to the side,” Henry said when he discovered a tunnel leading from the cave. “We’ll come back another time when we have our tape and rope.”

  “I wonder if anybody else knows about this section of the caves,” Jessie said, looking around. “I forgot to check for footprints before we covered up everything with our own footprints.”

  “Never mind footprints,” Henry said, bending down to get a closer look at the cavern floor. “Look at these holes.”

  The other three children came over to see what Henry was talking about. When Jessie shone the flashlight on the ground, they saw one, two, three huge holes. Each one was surrounded by a mound of mud, small rocks, and dirt.

  Suddenly, Jessie grabbed Henry’s arm. “Did you say something?” she whispered. “I just heard a voice.”

  “I hear two voices,” Violet whispered. “They’re getting closer.”

  Henry pointed to the wall. “Move over there into that crawl space. I’ll turn off my flashlight until we find out who’s down here.”

  In the dark, the Aldens squeezed themselves into a tight space carved into the cave wall. The next thing they heard were footsteps squishing through the nearby tunnel.

  “You and your stupid ideas,” a man’s angry voice said, just a few feet away. “Do you know how many tunnels are down here?”

  The Aldens recognized the second voice they heard. It belonged to Randall Pitt. “Don’t worry, Ed, we’ll find it. He said it’s down here. We just have to be patient.”

  “Patient? After you lost our other shovel and then got us lost, too? What if somebody else finds it first?” Mr. Lyme shouted. “These caves are crawling with people.”

  “Nobody’s looking for what we’re looking for,” Randall Pitt said. “So don’t worry.”

  Before Ed Lyme could answer, Benny felt his nose tickle. He tried not to think about the tickle. “Go away, go away,” he whispered to himself.

  “What did you say, Benny?” Violet whispered.

  “Ah—ah—ah-choo!” Benny cried when he couldn’t hold his sneeze in any longer.

  “What was that?” Mr. Lyme shouted just a few feet away from the Aldens. “Who’s there?”

  The children squeezed together as close as they could and prayed Benny wouldn’t sneeze again.

  “It can’t be those snoopy kids. I figure they were scared off after we pulled up all their tape, cut the rope on the oldest one, and made up that story about a cave-in,” one of the men said, shining his flashlight into the cavern.

  Luckily for the Aldens, the men didn’t see the crawl space the children were hiding in.

  “Come on. Let’s go down to the other end,” Mr. Pitt said. “We already dug here and didn’t find anything.”

  Then the men walked down the tunnel, dragging and scraping a shovel behind them. The Aldens waited several minutes before moving from their hiding space.

  “Whew,” Henry said, stepping out from the crawl space. “They’re gone.”

  “So Mr. Pitt was the one who took down our tape,” Violet said.

  “That was Mr. Pitt all right. And you know who else that was?” Henry pointed his flashlight on the cave floor.

  “Our monster!” Benny answered. “Their big wading boots made the footprints, and the shovel they were dragging made the tail prints.”

  “Good detective work!” Jessie said. “I hope you’re not disappointed. You were hoping there was a monster.”

  “Disappointed? Not me,” Benny said.

  But he was—just a little.

  CHAPTER 8

  Violet Finds a Treasure

  The Aldens wriggled out of the cave to have lunch in a warm, sunny spot.

  “Let’s put down our picnic blanket right here,” Henry said. “That way we can keep an eye on this cave.”

  Jessie set out the sandwiches. “What is it about these caves?” she wanted to know. “Every time we go inside, somebody wants us out of there. First it was Crystal Hollowell. Now it’s Mr. Pitt and Mr. Lyme.”

  “They’re searching for something, that’s for sure, ” Henry said. “But what could be under all that mud and dirt?”

  “Real diamonds!” Benny answered, very sure of that. “Those bad guys made big holes with that shovel. And know what? Maybe Joe Caveman is their partner, too. He had a book that said Treasure on it. Diamonds are treasure.”

  “Now don’t get your hopes up,” Violet said, looking up from Benny’s rock guide. “Your book says nearly all diamonds are found in South Africa. I don’t think diamonds are the treasure everyone’s looking for in the caves.”

  Jessie borrowed the rock book. “I’m going to read about the Rockville diamonds again to see if we can’t find our own treasure. Now where’s that page with the—hey, wait! Look at the photographer’s name under the picture of this rock.”

  Henry studied the photo Jessie was pointing to. “It says: ‘photograph by Crystal Hollowell.’ ”

  “Crystal Hollowell!” Jessie cried. “It can’t be the same person. She said she studied animals.”

  Violet looked over Jessie’s shoulder. “That’s what she said, but when we saw her in the cave, she was doing something with rocks.”

  Jessie flipped through the pages of the rock book. “Listen! It says here that sometimes streaks of silver are found inside a special kind of lead. And, listen to this: ‘Such lead deposits can be found in certain types of limestone.’ These caves are made of limestone! I bet that’s what Miss Hollowell and everybody else is looking for—silver!”

  “I bet for sure that Miss Hollowell took this picture,” Benny said. “Maybe if we don’t find our Rockville diamonds, we’ll find silver instead. Then we’ll be rich.”

  Jessie laughed. “It’s hard to find the kind of silver they’re talking about in this book, Benny. You have to be a rock expert to know what to look for. Those men were searching for something, and so was Miss Hollowell. But maybe it’s not silver, maybe it’s something else.”

  “But what?” Violet asked.

  “Don’t forget Joe Caveman!” Benny cried.

  “How can we forget Joe Caveman?” Jessie said with a laugh. “You won’t let us!”

  “Can we go back into this cave?” Benny begged. “Can we?”

  “I’d like to go back, too,” Violet added, forgetting all her worries about getting lost.

  Henry nodded. “Sure thing! I’m glad you changed your minds. I’d sure like to snoop around in there. But first let’s go back to the cabin and get our safety gear. Oh, one other thing. We have to let Mr. Howe know we’ll be caving here this afternoon.”

  After gathering up their things, the Aldens waited by the side of the road for the traffic to go by.

  Suddenly, a truck that was driving by slowed down in front of the Aldens. But a second later, it sped up again and disappeared.

  “Did you see who that was?” Henry asked.

  “Crystal Hollowell,” Jessie answered. “She took off like a rocket when she saw who we were.”

  Jessie checked down the road. “If we run, maybe we can see if she went to the other cave. It’s not far from here.”

  “Good idea,” Henry said. “Let’s go.”

  Jessie was right. After racing down a ways, the Aldens spotted Crystal Hollowell’s truck. Then they saw her, right by the sinkhole entrance.

  “Let’s try to catch up with her,” Jessie said. “Oh, Miss Ho
llowell, Miss Hollowell!”

  Hearing her name, Crystal Hollowell whirled around to see who was shouting for her. When she saw the Aldens, she marched back to her truck and threw her big duffel bag inside.

  Jessie ran over to the truck. “Wait up. We wanted to ask you something. Benny, hand me your rock book.”

  By the time Benny pulled his book from his backpack, Crystal Hollowell had started up her truck. “I’m in a hurry, so step back.”

  But Jessie Alden was much too fast for Crystal Hollowell. She opened the rock book and stuck it through the truck window. “Did you take this photo, Miss Hollowell? It has your name underneath it.”

  “I have no idea what you’re talking about!” Miss Hollowell answered without even looking at the book. “I’ve got to go.” With that, the young woman stepped on the gas and sped away.

  The Aldens hurried back to the cabin to get their safety gear.

  When they came down from the Little Nose Cliff again, they had everything they needed to go caving—except time.

  “I guess we should just look around the big cave we found this morning,” Henry said. “There’s not enough time to go back to the sinkhole cave, too. Besides, I left a note to Mr. Howe telling him where we’d be and that we marked the place with a bandana.”

  “The bandana!” Violet cried when the Aldens started searching for the cave entrance. “It’s gone!”

  The children walked along slowly, checking along the rock for the opening they had entered just hours before.

  “This is strange. I don’t see the entrance we dug out,” Henry said. He ran his hand along the rock to feel for the cool spot. “It should be easy to find since we scooped out all that rock and dirt.”

  Benny ran ahead to look for the spot. “I’ll find it! I’ll find it!” But he found no bandana sticking out and no cave opening.

  “A cave can’t just disappear,” Jessie said, walking up and down. “Let’s think. This morning when we crossed the road, we were standing next to that road sign. The cave opening has to be right near there.”

  “Hey, the entrance has been covered up! That’s why we didn’t see it,” Henry shouted when he checked the rock. “Somebody took the dirt and rock we dug out and pushed it back into the entrance!”

  It didn’t take long for the Aldens to dig out the entrance again. Soon, they were inside the cave. Now that they had four flashlights, there was plenty of light inside.

  “Hey, there are those bootmarks again—the ones with the heels,” Jessie said, aiming her flashlight at the cave floor. “Those aren’t our footprints, and they’re not big enough to belong to Mr. Pitt or Mr. Lyme. Let’s follow them.”

  Henry cut up many pieces of reflective tape. “This time we’ll put lots of tape high and low. Benny, take this stick and drag it along the floor as we walk. Whenever we get to a turn, make an ‘X’ in the mud. If we leave enough markers, there’s no way anyone can erase every single one.”

  With their safety rules all set, the Aldens walked through the tunnel that branched off from the first room of the cave.

  “Wow!” Benny yelled a few minutes later, running ahead. “You won’t believe what I just found.”

  Benny’s voice was coming from a room-sized space off the side of the tunnel. Squeezing in behind, Henry, Jessie, and Violet beamed their flashlights into the space.

  “It’s like a small living room,” Violet said. “There’s a folding stool, some books—even a sleeping bag.”

  “Whom could this belong to?” Jessie said.

  “Not to the person we’re trailing, that’s for sure,” Henry said, aiming his flashlight at the floor. “There’s only one set of footprints in here, and they’re way bigger than the ones we were following.”

  Violet picked up a book lying on the stool. “Look what I found.”

  The other children’s eyes grew huge. Soon everyone was laughing very hard.

  “It’s—it’s . . . ” Henry started to say before he burst into laughter again.

  “Treasure Island,” Jessie finally managed to say between fits of laughter. “It’s the book Joe Caveman was carrying the day we saw him. He wasn’t looking for a treasure at all. He was just reading—”

  “Treasure Island!” Benny cried. “That’s the book you read me last summer about a shipwreck.”

  Jessie put her arm around Benny. “Remember how much you liked it?”

  Benny nodded. “Not as much as I like real treasures. That’s a funny joke on us.”

  The next thing the children heard wasn’t a funny joke at all. Loud, stomping footsteps echoed in the cave.

  “Quick!” Henry whispered. “Turn off your flashlights. Maybe we can see who’s going by.”

  “Or coming in,” Violet whispered when a bright spotlight suddenly lit up the chamber.

  “Who’s in here?” a man’s voice boomed.

  There was no use hiding. The Aldens came out from the shadows.

  “Joe Caveman!” the children yelled all at once.

  “I guess you found my hideout,” the tall stranger said.

  Benny burst out with a question. “What are you hiding in your hideout?”

  Joe Caveman pointed to himself. “Me. I’m hiding me.”

  Violet swallowed hard. “Is someone looking for you?”

  For the first time, Joe Caveman smiled. “Everybody’s looking for me, young lady. My five children, my wife, my boss. I never get a second to myself. I come down here for some peace and quiet on my days off to do a little reading and some exploring. I’m a spelunker.”

  “We’re ’lunkers, too,” Benny said. “But we don’t read books down here. We’re looking for diamonds and silver and two men who made us get lost.”

  “Whoa, young fella, slow down,” Joe Caveman said. “I hope you folks weren’t the ones who hammered the walls at the sinkhole entrance where I first ran into you. There were some rock chips over there.”

  “That wasn’t us,” Benny said. “That was a lady who tried to scare us. She said we’d get flooded even though it was sunny out.”

  “Never saw her,” Joe Caveman said. “As for the two men you mentioned, I wonder if they’re the pair I chased out of here after I caught them digging up the cave.”

  “We saw them, too,” Jessie said. “They took down all our reflective tape to scare us, and they cut our brother Henry’s rope. Everybody seems to want us out of here.”

  Violet looked up at the tall stranger. “Do you want us out of here, too?”

  Joe Caveman smiled at Violet. “Not at all. Sorry I was so gruff the other day. I’d just settled my things down in a good spot when those men came down making a racket with their digging and yelling. All these caves connect, so I moved on and found this hideout farther in. But caves are public places—wonderful places if you know what you’re up to. I can see you children are very careful cavers, so I don’t mind that you’re down here. Hope I didn’t scare you the other day.”

  “You did,” Benny said with a laugh. “But not for long.”

  “Good.” Joe Caveman picked up his belongings. “I guess I’ll be off. Half the fun is trying to discover a spot where nobody can find me.”

  With that, Joe Caveman was gone.

  Benny ran after him. “Hey, wait!” he said. “You forgot something.”

  Joe Caveman turned around. “What?”

  Benny handed Joe Caveman his book. “Your treasure.”

  CHAPTER 9

  Trapped Underground!

  After saying good-bye to Joe Caveman, the Aldens spent the rest of the afternoon exploring the new cave.

  “Know what?” Benny asked as he walked along with his brother and sisters. “Joe Caveman never told us his real name.”

  “I like the name you gave him way better than any real name,” Violet said. “Henry, why are you stopping?”

  “Because we hit a dead end,” Henry said when he came to a rock wall.

  Jessie checked her watch. “It’s four o’clock. We should get back before Mr. Howe worries abou
t us. And don’t forget. Grandfather will be back tonight. We have to pack for Greenfield.”

  “Nuts!” Benny said when they turned back. “I didn’t find a Rockville diamond or any silver or figure out any mysteries to tell Grandfather.”

  “We found out about Joe Caveman,” Henry said. “That was a mystery we solved.”

  “That wasn’t a real mystery. He was just a plain old person reading his book in a cave,” Benny complained.

  When the Aldens spotted the last piece of tape, Henry pulled it down. “Wait a minute. Is this where we started? I don’t see the exit. There’s no light in here except for our flashlights.”

  Jessie went over to the far wall of the cave. “The entrance is blocked!”

  Henry came over and began to dig out rocks and dirt from the opening.

  “What’s the matter, Henry?” Violet asked.

  Henry waited a long time before answering. “There’s a boulder or something very heavy pushed against the outside. It’s way too heavy for me to move.”

  “Are we trapped?” Benny asked, his voice cracking.

  Jessie tried not to sound scared. “I’ve got an idea. Let’s go back to where we saw Joe Caveman leave. He went out a different way. We’ll just follow his footprints, and I know we’ll get out.”

  The Aldens walked quickly back through the dark cave.

  “Benny, you stick up the tape this time,” Henry said. “And Violet can drag the stick along and mark our turns with an ‘X.’ Let’s get a move on.”

  Finally, they were back in Joe Caveman’s “living room.”

  “Okay,” Jessie said, “here are Joe Caveman’s footprints. Let’s just follow them until we see daylight.”

  “Wait, I think I hear something,” Henry said.

  “Stop! I hear water rushing near here,” said Jessie.

  “Is it a flood, Jessie?” Benny asked. “What if there’s a big thunderstorm outside?”

  “Let’s check where the sound is coming from,” Jessie said as calmly as she could. “Maybe it’s just an underground stream. That would be good because it could lead us out of here.”