The boys barely had time to take cover as the large rocks began falling around them. Within seconds, the entire area where they had been standing was completely covered in fallen debris.

"Is everybody all right?" asked Frank, as he got to his feet and began dusting himself off. He, along with Jerry and Chet, had managed to take cover in a large crevice in the side of the mountain.

"I'm all right," replied Jerry, in a shaken voice. "What about you Chet?"

"I think so," replied the plump youth. "I don't think there’s anything broken." Then he reached into his backpack and produced a large candy bar that he had brought along. After a careful examination, Chet smiled and said, "Nope, everything’s fine!"

"Joe, How about you?" Frank gasped as he turned to face his brother. Neither Joe nor Biff was anywhere to be seen! "Joe!" He shouted. "Biff!" There was no response.

In the meantime, as the boys were beginning to panic over the missing hikers, Mrs. Hardy and Aunt Gertrude had just arrived at the Advantage Falls Livery Stable.

"That’s the boys' car." Laura Hardy breathed a sigh of relief as soon as she spotted the familiar looking sporty convertible setting in front of the old wooden barn. "They must have made it this far without any problems."

"What were they doing here?" asked Gertrude. "Better yet, what are we doing here?" By now, the old woman had overcome her terrifying experience with Cedar Ravine. "You don't expect me to go on horse back do you?" She peered over the rim of her glasses.

"It's the only way," smiled Laura, parking Chet's jalopy next to the boys' car.

"I'll just wait here for a taxi," Gertrude remarked as the two ladies walked inside of the building.

"I'm afraid you'll never get a cab to go out there where your nephews are," the owner of the stable spoke up, as he began to saddle up two horses. "It's much too rough for an automobile."

"I guess we don't have any choice then," the old woman finally conceded to the notion of traveling by horseback. She then glanced up at the sky, which was clouding up again. "It looks like another storm," she remarked. "I hope those boys are satisfied. We'll probably all catch pneumonia!"

"Well then, you ladies need to be on your way," the stableman remarked as he helped Mrs. Hardy up onto her horse, "before the weather gets too rough." When he turned to help Aunt Gertrude onto her horse, he was surprised to find that she was already up there.

Miss Hardy then gave her horse a nudge and it took off at a gallop. "Come on Laura!" she shouted. "Let's not have any lollygagging!"

Laura sat there for a moment a little shocked over the way Gertrude handled her horse. It was like watching an old pro, which was something truly surprising. In the past, Miss Hardy had expressed a great deal of distaste for the beasts. Nudging her own horse, Mrs. Hardy fell in behind her sister-n-law.

As the two ladies continued on their journey, Frank and the others were still busily searching for their missing friends.

"Wait a minute!" said Jerry, as he leaned over a huge pile of rocks. "I thought I heard something," he whispered.

"Help!" A muffled voice was heard coming from behind the rocks.

"Joe!" shouted Frank. "It's that you?"

"We're trapped!" the voice replied.

When the avalanche had first begun, like Frank and the other two boys, Joe and Biff both lunged for a hollowed out place in the side of the mountain. Unfortunately, the place they dove into had become completely barricaded by a large pile of rocks and small boulders.

"What are we going to do?" asked Jerry, nervously.

"We'll have to dig them out," replied Frank, determinedly.

"But those rocks must weigh a ton," groaned Chet. "It will take us forever!"

"Do you have any other ideas?" asked Frank, curtly, as he removed his backpack and placed it on the ground.

"Joe, can you and Biff breathe?" asked Jerry Gilroy. The boys had been carrying rocks away for about an hour now.

"Yes," replied Joe, whose voice could be heard much clearer now. "There's a slight breeze coming in from somewhere."

"Just hang on," Frank spoke up. "We're almost there."

"Yeah, don't go anywhere!" grinned Chet.

Frank and Jerry each gave Chet an annoyed glance. They didn’t see any humor in the situation at all.

Twenty minutes later, there remained only one boulder between the lost boys and freedom. Frank, Jerry and Chet heaved on it with all of their might, but it wouldn't budge.

"Try pushing on it from inside," suggested Frank.

Again, all of the boys struggled trying to remove the huge rock, but it still didn't move. Joe and Biff even tried bracing themselves against the side of the cliff and pushing the rock with their legs, but that didn’t work either.

"I'm exhausted!" Jerry finally was forced to admit that he couldn’t strain himself any longer on the giant rock. He then turned on his heel and flopped down on the ground. Frank and Chet, who were just as equally tired, collapsed next to him.

By now all of the boys’ hopes were at an all time low. Chet, who hadn't eaten in almost an hour, reached into his backpack and produced a sandwich. As he removed the sandwich, an apple accidentally fell out of the pack and landed onto the ground. It rolled across the rocky ground and into a small opening between the boulder and a dirt embankment.

"We’re done for," remarked Biff. He had about given up hope on Joe and himself being rescued.

"Maybe not," Joe replied hopefully. "If worse comes to worse, the others will simply leave us here and go for help."

"I'm getting kind of hungry." Biff slumped down on the ground.

"I know," replied Joe, as he sat down next to his friend. "I am too." As he said this, he glanced over at an object that had just rolled up next to his foot. He then picked it up and casually asked the other captive, "Do you want to split this apple?"

Suddenly, it dawned on Biff and Joe at the same time!

"Frank!" Joe shouted. "We've found a way out!"

After the others were informed of the situation, they removed the small shovels from their backpacks and began digging into the dirt embankment. The dirt was pretty easy to dig into because of all the rain from the previous day. It had softened the earth up nicely, so it didn't take very long before they had dug out an opening big enough for Joe and Biff both to crawl through. As soon as the two boys were safe and sound, Chet gave each of them a sandwich, and they all ate heartily.

"That was no accident!" remarked Frank, glumly. He had just finished his second sandwich and was looking back up towards the face of the mountain. "Whoever I saw up on that ledge must have set off a small charge of dynamite."

"You're right," agreed Joe. "But what was their motive?"

"I don't know," replied Frank. "But evidently the fiends that we're dealing with are more than just litter bugs."

"I knew it!" Chet blurted out. "We can't go anywhere without the two of you running into a mystery." He paused to frown. "This was supposed to be a pleasant trip with no worries, no cares, and no MYSTERIES!"

"It wouldn't be so bad," Jerry piped in, "If they just didn't drag us into it!"

"You said it!" shouted Biff.

Frank and Joe glanced at each other, each trying to hold back a grin. "Well if that's the way you feel about it, then the three of you can stay back at the camp while we conduct our investigation. Of course, whatever reward money we might get, we’ll naturally just be splitting between ourselves."

"What!" the others replied in unison.

"No way!" said Biff.

"Not a chance!" said Jerry.

"And miss out on all of the excitement?" Chet laughed. "We wouldn’t think about it!" The boys all howled with laughter. Frank and Joe knew that no matter how their friends complained, they enjoyed being a part of their adventures.

Just then, above their heads, came the sound of an enormous clap of thunder. "But," Frank spoke up, "It’ll have to wait until tomorrow. We need to hurry back to camp."

The boys didn't waste any time making it back to their campground. It was a good thing too, because they had barely made it into their tent before the heavy rain started coming down in sheets. This storm only lasted a couple of hours, but by the time the rain had stopped, it was too late to go back up on the mountain. About eight o'clock, the boys made another campfire, hoping it would help dry out the ground around them.

"Who do you think is up there?" asked Jerry, as he sat down on a log by the fire.

"Yeah, who could want to hurt us?" asked Chet.

"I don't know," replied Frank. "But whoever it is wants us out of the game permanently, that’s for sure."

"I think we should take turns standing guard again tonight," suggested Joe, as he placed another piece of wood onto the fire.

"This time I'll take the first watch," stated Biff.

It was agreed, and they divided the night into five shifts, Biff taking the first one. About an hour later, they decided to turn in. When Biff's shift ended, Chet took over.

Chet brought his sleeping bag with him and set it up underneath a tree. Shortly after midnight, his eyes began to get heavy, and despite his efforts to stay awake, he slowly dozed off. As the plump youth lay there sleeping, completely unaware of his surroundings, a strange man slowly emerged from the woods and began to creep up on him. Every now and then, he would step on a twig and would wait to make sure he wasn't heard.

The stranger was only a few feet away when Chet suddenly woke up. At first, he didn't realize what was going on and before he could utter a single word, the man suddenly let out a yelp of pain. He then fell forward, landing on the ground with a loud thud!