“Adding paleo means that the burrow was built by an extinct creature,” Dr. Iris explained.

  “So you think this tunnel is thousands of years old?” Violet asked. “Wouldn’t it have fallen in?”

  “Exactly!” Nigel said. “I think this burrow is much more recent.”

  “We tried to build a snow tunnel last winter,” said Benny. “But it fell in.”

  “Tunnels have to be made of just the right stuff,” Dr. Iris said. “The ground here is very compact.”

  “Maybe that’s why our tunnel didn’t work,” Benny said.

  “That, and Watch jumped on it before it was ready.” Henry chuckled.

  Benny nodded. “I don’t think he likes tunnels.”

  Jessie looked around the entrance. “How was this tunnel found?” Jessie asked.

  Kwini spoke up. “A woman from a bird expedition told Nigel about it. The area had been cleared by illegal loggers. According to the woman, when the loggers found the tunnel, they packed up and left.”

  “I would too,” said Jessie, “if I didn’t know about the giant ground sloths.”

  The group followed Nigel a little farther into the tunnel. It became dark very quickly. Nigel turned on his flashlight.

  “What if a mapinguary is hiding in here?” said Benny.

  “Or anything else,” Violet added. She remembered what Captain Souza had said about being good guests in the rain forest. She didn’t think a good guest would walk into an animal’s home.

  “It makes it more exciting that way!” Nigel called over his shoulder.

  He turned on a camera attached to his vest and began to move down the tunnel. “It is believed these amazing structures were made by giant sloths,” he said for the camera, “but there is no way of dating them. They may very well have been made more recently by the ferocious mapinguary that roams the forest. We have to go quietly.”

  Dr. Iris, Kwini, and the children followed at a distance. “I disagree with Nigel,” Dr. Iris said. “I do think it is a paleoburrow and was made a very long time ago. I think we are fine to go farther in.”

  They all switched on their flashlights and followed after Nigel. The tunnel was so large no one had to duck their heads.

  “We think it goes several hundred feet into the hill,” Nigel said from up ahead.

  Henry’s fingers brushed the wall as he walked. There were rough ridges carved into the wall.

  “The ridges are a clue,” said Dr. Iris. “Scientists think they were made by an animal with large claws scraping the soil away. The ridges would then be the spaces between the claws.”

  “The claws on the giant sloth skeleton were long enough and big enough to be able to dig,” Jessie said.

  “So were the ones on that scary statue,” Violet added.

  Henry stopped and looked around. “But when you dig a long tunnel, you have to put the soil somewhere,” he said. “How would an animal carry it all out of here?”

  “A very good question,” said Dr. Iris. “They would have to keep scooping it backward as they backed out of the tunnel. It would be a tremendous amount of work.”

  “They must have figured out a way,” Jessie said. “I’ve seen pictures of how prairie dogs have a whole network of tunnels.”

  “This would be one big prairie dog,” said Benny.

  The group continued down the tunnel. Nigel was so far ahead they could see only his silhouette and the light from his flashlight bobbing up and down.

  “I don’t hear anything,” Benny said. “That means there is probably nothing in here, right?”

  “Right,” Jessie said. “I think we are safe.”

  Suddenly, Nigel stopped narrating for the camera ahead, and his light swept back and forth across the tunnel. “I think there’s something here!” he called.

  The next thing the Aldens knew, Nigel’s light went out, and he let out a shriek.

  Dr. Iris took off running toward him, and the children followed with Kwini. When they reached him, they shined their flashlights around the tunnel. They had reached the end. “Nigel, there’s nothing here,” Dr. Iris said. “Are you hurt?”

  There was silence for a moment. Then Nigel said, “Why did you have to say that? I was making a good video!”

  “We thought you were in trouble,” said Jessie.

  “No, no. But now I need to do another take. Everything was going so well too!”

  The group walked out of the tunnel. When they got to the entrance, Nigel turned on his camera and began again. “It is believed these amazing structures were made by giant sloths, but they have been made by the ferocious mapinguary that roams the forest. There may be one inside…”

  “Why is he saying that?” Benny asked. “He knows there isn’t anything in the tunnel. We walked all the way to the end.”

  “He’s just pretending for the film,” Henry said.

  “That doesn’t seem right,” said Violet.

  Dr. Iris shook her head. “No, but it’s very common, I’m afraid. Often what you see on television is staged to make something seem more frightening than it really is.”

  “Not your program though,” said Violet. “Right?”

  Dr. Iris shook her head. “Our show is to learn about the legends and examine the evidence.”

  “Is there any evidence to prove the tunnel was made by giant sloths?” Jessie asked.

  “That is a very good question,” Dr. Iris said. “It would be very difficult to say.”

  “What if someone found a skeleton in one?” Benny asked.

  “Or a fossil claw stuck in the wall?” Violet suggested.

  “A skeleton or a fossil claw found like that would be excellent proof,” Dr. Iris said. “But the conditions in the rain forest aren’t right to turn something into a fossil. Remember, the best way a bone becomes a fossil is when it is covered up with dirt. A claw stuck in a tunnel wall like this would just break down and disappear.”

  Henry looked at one of the walls near the entrance. “That’s too bad,” he said. “It really does seem like an animal made this tunnel. I wish we could find some real evidence.”

  The children were quiet for a moment. Then Jessie spoke up. “We did find evidence in one way,” she said. “No matter what made this tunnel, we learned that the legend of the mapinguary kept the loggers away.”

  “Excellent point,” said Dr. Iris. “Yes, the power of stories can be very strong. I have a feeling that will be an important part of our research.”

  The trip back seemed to take longer than it had to get to the tunnel. It was almost dusk by the time they tied the boats up. As they ate dinner around the campfire, the Aldens were happy to relax after a long day of travel.

  However, Nigel was restless. He walked around the camp with night-vision goggles, looking for footprints. “Take a look at this beauty!” he called.

  Everyone hurried over, and Nigel pointed down to a large leaf.

  Violet got close enough to see and then jerked back. “Is that a big spider?”

  “It is!” Nigel said. “It’s a pink-toed tarantula. Isn’t it fantastic? Look at its toes. They really are pink. I used to want a tarantula as a pet, but my father hates spiders.”

  “Aren’t they dangerous?” Jessie asked.

  “Not if you are careful,” Nigel said. “They can even be held if you don’t startle them.”

  “I thought…” Henry began. “Professor Cardoso said you hate spiders.”

  Nigel frowned. “No, I don’t hate spiders. He must be confused. I’m going to get my camera and film this. It will go great with the bits about the dangers of the Amazon.”

  After Nigel was done filming, he got out his audio recording device. It contained the audio recording he had sent to Dr. Iris early in the trip. “I’m going to play it, and maybe one will answer back.” He played the roaring noise, and everyone sat quietly and listened for a response.

  “I just hear the regular sounds,” Violet said finally. She was relieved nothing had roared back.

  “Nigel, I’ve been wondering, where did you get the recording?” Dr. Iris asked.

  “A man in Manaus,” Nigel replied. “People there know I’m looking for the mapinguary and that I’ll pay for good information. The man came to me with the recording and the location where he heard it. He swore he’d never heard anything like it before.”

  “It could be a jaguar,” said Dr. Iris. “Did you compare the sound you have to the sound of a jaguar roaring?”

  “No, the man who gave it to me knows this area,” Nigel said. “He wouldn’t claim it was a mapinguary if he knew it was a jaguar.”

  “Maybe he just wanted to be paid,” Kwini suggested.

  “It’s too bad we can’t get a signal on a cell phone,” Henry said. “It would be easy to find a recording of a jaguar on the Internet.”

  Nigel put the equipment away. “Well, we can’t. I’ll try again tomorrow night. I have something else I need to work on.” He got out one of the laptops he had brought. “Want to help me with a ghost story I recorded? I put a new one up on the Internet every month, and I’m going to need to upload this one as soon as I get back to Manaus to keep on schedule.”

  “What do you want us to do?” Violet asked.

  “I need some sound effects. I tell the stories, but then I add in extra touches. Here, I’ll show you what I mean.”

  They listened to a spooky story about a haunted house that had sound effects added in.

  “Did you write that story?” Jessie asked. “It’s really good and scary.”

  “I did, and I’m glad you thought it was scary,” Nigel said. “The one I’m working on now is about a family of ghosts.”

  The children agreed to help Nigel make sound effects for his story. Henry and Jessie played the parts of the older ghosts, and Violet and Benny played the parts of the two younger ghosts. When they were done, the children laughed as they went into their shelter to go to sleep for the night. Making sound effects was a fun distraction from thinking about scary monsters.

  But as Henry laid in his hammock, he wondered: Why was a scientist so interested in making stories?

  A CLOSE CALL

  The next morning, Nigel was up first. By the time they had all finished eating, he was ready to go. “We’re going to hike to our site today. I think it’s a perfect spot for a mapinguary to live,” he told them. “Even if we don’t see one, we might find footprints!”

  Dr. Iris helped pack up the right supplies, and they started to hike on an old trail through the rain forest. They had traveled almost two hours before Henry spotted something unusual. The path appeared to end at a wall of vines.

  “Is that a building up ahead?” he asked. “I can see stone blocks underneath the vines.”

  “Yes,” Kwini said as they drew closer. “There must have been a town here a long time ago.”

  “This is it!” Nigel said.

  At the end of the wall, the path turned into an overgrown street. Small trees sprouted between paving stones, and vines trailed across it. Nigel went down the street and spent time filming the area.

  “What is this place?” Jessie asked.

  Parts of buildings, mostly collapsed, lined both sides of the street. The roofs of the buildings were gone. Plants and trees were growing out of the floors.

  “I do not know its name,” Kwini said. “But there are abandoned towns like this in many places in the Amazon.”

  “It’s strange to think people abandon whole towns,” Henry said.

  “They were built when farming for rubber was legal here,” said Kwini. “After farmers started growing rubber trees in other parts of the world, people slowly moved out of towns like these.”

  “I thought more of the buildings would be intact,” Nigel said, filming as he went. “An old building would be a perfect lair for a mapinguary.”

  “The trees grow quickly here,” said Dr. Iris. She scanned the old buildings. Some of the trees were quite tall. “I would guess that this town has been abandoned for at least ten years.”

  “It’s closer to five,” said Kwini.

  “Wow,” said Jessie. “That’s amazing.”

  Dr. Iris reached out and grabbed a branch extending through an empty window. “Remember how we talked about how everything in the rain forest changes over time?” she said.

  Jessie nodded.

  “The plants and trees do too,” she said. “Every plant in the forest has adapted to grow quickly. If it doesn’t, it will be overtaken by those that do, and it will not receive the water and sunlight it needs. That’s one of the reasons things grow so quickly here.”

  “So each plant is like a master grower,” said Benny.

  Dr. Iris smiled. “That’s one way of putting it.”

  Violet looked at the beautiful plants growing in the old town. She liked the idea of the rain forest growing back after people were gone.

  After a few minutes, Nigel returned to the group.

  “I want to look for footprints behind the buildings,” he said. “It’s possible mapinguaries do come here. Maybe they are waiting for the humans to come back! I need to record that idea.”

  He went back to recording himself talking about mapinguary lairs and humans walking into danger. When he was finished, he moved to the back of the buildings.

  Benny looked around the abandoned town. “His video is going to be scary! What if one really is waiting here?”

  “This village has been abandoned for a long time,” said Henry. “Even if there was a creature, it wouldn’t wait around for someone to show up. But it is a spooky idea.”

  “I found a footprint!” Nigel called.

  The group hurried around a building to where Nigel was pointing at the ground. There was a mark in the soil that looked like no footprint the Aldens had ever seen before. At the back there was a deep print that looked like a heel mark and four long prints that looked like claws.

  “Maybe someone created it,” said Violet. “Like the bigfoot prints we found that were made-up.”

  Everyone turned to Nigel.

  “Hey, don’t look at me!” he said. “I didn’t have the time to make this.”

  It was true: unless Nigel had created the footprint some other time, there was no way he could have made it.

  Kwini looked around. “I don’t recognize this footprint,” he said. “But I can tell that it’s fresh.”

  “What do you think, Dr. Iris?” Henry asked.

  She bent down to examine it. “I’m not familiar enough with the rain forest to tell. It could be a footprint, or it could have been caused by something else, like an animal stepping on a branch.”

  Nigel scouted the area and then called out, “This might be another one! I need to take a cast of both of these.”

  “A cast?” Violet asked. “What does that mean?”

  “A cast is a way of taking a record of a footprint,” said Dr. Iris.

  Nigel set down his backpack and pulled out a bag of white powder. “Kwini, can I have some water? The instructions say to cut the top off the bag and pour the water in, then mix it around.”

  “It’s much easier to mix in a bucket,” Dr. Iris said. “I’ve taken hundreds of casts, if you’d like me to do the mixing. I can get the consistency just right.”

  “All right.” Nigel handed over the supplies to Dr. Iris.

  “You need to get the water out of the impression first,” she said. “Clear all the leaves and twigs out of it. Then use the paper towels to soak up the water.”

  When the powder was mixed, she said, “It’s tempting to pour a lot in the center and let it spread out, but that can change the shape. We’ll pour it slowly around the edges and it will fill in.” She did so, then she pulled out a ruler from her pack. “Now, we smooth it down so no air bubbles remain. It will take a while to dry. We’ll have to leave them here and come back.”

  “That’s okay. We can look around some more,” Nigel said.

  While the casts were drying, the group explored the area. They hadn’t gone far when Nigel stopped. He grabbed Kwini’s arm. “I saw something move! Let’s follow it!”

  “Wait,” Kwini said. “We can’t just run after it. If there is an animal out there, it will run away.”

  “Whatever it is, it probably knows we are here already,” Jessie said. “Almost all animals can smell better than humans.”

  “I think I smell something,” said Violet, scrunching up her face. “And whatever it is, it’s not good.”

  “We have to follow it,” Nigel said. “No one will believe me unless I get something on film. Kwini, get out the net, and Henry, be ready. The two of you run around the creature, one on either side until its trapped in the net. I’ll film it all.”

  Kwini and Henry looked at each other. Kwini shrugged and then got out the net, handing one side of it to Henry.

  “You don’t really think you can catch whatever it is!” Dr. Iris said to Nigel.

  “We can try,” Nigel said. “It’s why we are here, after all.”

  “We’re here to see how the legend could have come about, not to actually try to capture a large animal!” Dr. Iris said.

  Nigel ignored her and switched on the camera. He held up his hand for everyone to be quiet. “We’re here, deep in the Amazon jungle,” he said into the camera, “on the trail of what may be the amazing discovery of the century! An actual monster of the Amazon, the legendary mapinguary is a creature so fearsome that people who live here tremble at its mere mention.”

  He motioned for everyone to move forward as he began to walk. After a few minutes, they came to a clearing. Nigel motioned for everyone to stop. Ahead, a large, hairy creature was hunched over something on the ground. The creature reared up and put its front legs on the tree. Then it turned its head toward them.

  Benny grabbed onto Jessie’s hand. Violet clapped her hand over her mouth.

  “Back up,” Kwini said. “It’s not going to attack us. It’s just warning us off.”

  But instead of letting out a roar, the creature let out a small squeak. Then it put its front paws back onto the ground and waddled off into the forest.

  “Did you see its long snout?” Jessie said. “That was definitely not a monster.”

  “It was an anteater!” said Benny. “We saw one at the zoo!”