THE SECRET OF THE CAVES.

FRANKLIN W. DIXON.

CHAPTER I.

Telescope Hill Trouble.

DON'T kid me, fellows," chubby Chet Morton said, moving his metal detector about the Hardys' front lawn. "You can find all kinds of swell things on the beaches with this gadget."

"Like what?" blond-haired Joe asked, winking at his brother Frank.

"Lost jewelry, money, gold-plated pens-"

Chet was interrupted by the arrival of a tall, broad-shouldered youth.

"Hi, Biff!" Frank called out. "Chet's trying to find a treasure."

Biff Hooper examined the new device and raised his eyebrows. "I know just where you can use this, Chet. You might find a lot of valuable stuff."

"Where?"

"At the Honeycomb Caves. My grandfather told me a freighter was sunk off the point during a hurricane.

Lots of stuff was washed up."

"Just what I told you," Chet said with a supercilious glance at the Hardy brothers.

Frank, eighteen, and Joe, a year younger, looked skeptically at their enthusiastic friends.

"There are a lot of important things to be found!" Chet burbled. "How about the four of us going on a trip together?"

"To the Honeycomb Caves?" Joe asked. "Sure. Why not? It's only fifty miles down the coast. Good swimming and fishing there, too."

"I'll explore the caves for hidden jewels," Joe said dryly, "while you and Biff pick up a million dollars'

worth of rusty nails."

"It's a deal," Biff said, laughing. "Let me try that gimmick, Chet."

The stout boy removed the earphones from his head and handed Biff the long, thin tube with a metal disk at the end.

"When you hear a loud clicking," Chet said, "you know that something metallic is under the ground."

His face intent, big Biff moved about the gra.s.s with the detector. Suddenly a voice from inside the house called, "Frank! Joel"

"Okay, Dad, we're coming," Joe answered. He leaped up the front steps three at a time, with Frank at his heels.

Inside, Mr. Hardy, a tall athletic man, motioned his sons into his study.

Fenton Hardy's reputation as a sleuth was worldwide. A former crack New York City police officer, he had moved to Bayport to become a private detective. Now his sons seemed destined to follow in their father's footsteps.

"What's cooking, Dad?" Frank asked as the two boys sank into comfortable seats.

"Another mystery?" queried Joe.

Mr. Hardy flashed a smile, then became serious and opened a dossier before him on the desk. "I've got important news," he said.

"About what, Dad?" Joe asked.

"Telescope Hill."

"Where the U. S. is erecting the Coastal Radar Station?" asked Frank.

"Exactly."

"What's going on there?" Joe asked.

"Trouble. That's all I know so far," Mr. Hardy replied. He told his sons that he had been deputized by the U. S. Government to aid in security at the gigantic installation designed to protect the coast of North America.

"To hunt out spies?" Joe asked.

"More likely saboteurs. There have been some strange, unexplained accidents at the site."

"Attack from within?" Frank queried.

"Yes. Perhaps a guard. That's my guess. So I'm going to reorganize the guard security system and nip any trouble in the bud. I thought you boys might like to help."

"Sure, Dad!" Frank said. "Will we need disguises or anything?"

"Not exactly."

"But," Joe began, "Chet wants us to-"

"That can wait," Frank interrupted impatiently. "Can't you see, Joe, we might be heading into a dilly of a mystery?"

Just then the quiet of the balmy June afternoon was shattered by a wild shriek in front of the Hardys'

home. Frank and Joe jumped up, startled.

"Good grief, something's happened!" Frank exclaimed.

Both boys dashed out of the house, followed by Mr. Hardy. Chet was jumping up and down on the front lawn, while Biff, looking excited, made the metal disk hover above a spot on the lawn.

"He's found a treasure!" Chet cried out. "This thing's clicking like fury. We've really got something, Frank!"

Several cars pa.s.sing the Hardy home slowed down as the drivers watched Chet's antics. Then a huge trailer truck, carrying a load of construction steel, came to a halt while the driver honked for the cars to move on.

"More material for the radar installation," Frank thought as the long vehicle rumbled out of sight down the street.

"Look, it's right about here," Biff said. He took off his earphones and marked an X on the gra.s.s.

"Do you expect us to dig up this fine lawn to satisfy your tomfoolery?" Joe said in mock seriousness.

"We just can't let it lie there," Chet protested. "Suppose it's an old coin worth hundreds and hundreds of dollars."

Now Mr. Hardy was interested. With a wink he said, "Okay, boys, dig it up. Let's see what good detectives Chet and Biff are."

Chet ran to the garage and returned with a shovel. With it he carefully cut the turf, placed it to one side, and probed the dirt with the point of his shovel. He hit something hard and metallic.

"What did I tell you?" Chet beamed. "This detector is the greatest. Oh boy, are we going to have fun at Honeycomb Caves!" He dug up a shovelful of dirt, which he deposited beside the hole.

From the soil fell the metallic object The Hardys recognized it as a tiny toy fire engine, rusted and corroded.

As the others crowded about, Joe picked up the toy and wiped off the crumbling earth which clung to the wheels. "Thanks, Chet," he said gravely, "I lost this fire engine seven years ago when I was ten."

"You were probably trying to hide it from me," said Frank, and laughed.

"Well," said Biff, "we've found Chet's Number One treasure. What's next? A ship's compa.s.s at Honeycomb Caves?"

Chuckling, Mr. Hardy excused himself, while the boys chatted about the trip.

"I'm afraid we can't go, fellows," Joe said.

"Not at this time, anyhow," Frank chimed in. "We have to work on a case with Dad."

"Say, what is going on?" Biff demanded.

"We can't tell," Frank replied. "It's confidential."

"Whatever it is," Chet said, "count me out of any dangerous stuff." Their stout friend bemoaned the fact that every time they were about to have fun, some sort of detective work had to come up.

Chet already had been involved in some deep mysteries which the Hardy boys had solved. But in each case, although reluctant at first, their staunch friend had joined in the sleuthing as an invaluable ally.

"When can you come with us?" asked Biff, evidently as eager as Chet to explore around Honeycomb Caves.

"That depends," said Frank, "on-" His eyes were suddenly diverted by someone walking up the street.

The other three boys turned to see an attractive girl, about their age, hurrying along the sidewalk. She had wavy jet-black hair, flashing brown eyes, and a gait that told the world she was in a hurry.

"A new neighbor?" Biff whispered, grinning.

"I've never seen her before," Joe said.

The girl, heels clicking, hastened to the Hardys' front walk. There she stopped suddenly, turned toward the boys, and took a few steps forward.

Chet gave a low whistle and rolled his eyes. The girl, although she had a pretty face, wore a sad, worried look. "I would like to speak to the detective," she said nervously.

Joe's face brightened. "My brother Frank and I are detectives," he replied. "May we help you?"

"Don't mock me," said the girl, and her lower lip quivered.

Frank and Joe were taken aback. But they were even more nonplused when their caller suddenly burst into tears!

CHAPTER II.

Over the Fence.

"HEY, wait a minute!" Joe blurted. "Don't cry!" But tears continued to course down the girl's face.

As the boys looked on in embarra.s.sed silence, Mrs. Hardy hurried out of the door, followed by her husband.

"Goodness gracious!" exclaimed Laura Hardy, a slim, good-looking woman. She hastened to the girl and put an arm about her shoulder. "Come inside, dear. Perhaps we can help you."

Frank whispered to Chet and Biff, "Wait here until we find what this is all about."

Mrs. Hardy sat on the living-room sofa beside the young caller. The girl dried her eyes and announced that her name was Mary Todd. She sobbed once more and said, "My father was a friend of yours, Mr.

Hardy."

"Oh, yes. George Todd of the Redding Machine Company. A fine man. I haven't seen him for years."

"Well, Dad pa.s.sed away, and Mother, too," the girl said.

The Hardys all expressed sympathy. Then Mary explained, "That's not why I'm crying, though. It's about my brother."

Mr. Hardy leaned forward in his chair and said, "His name is Morgan, isn't it? As I recall, a very bright boy. A little older than my sons."

Bravely fighting back tears, Mary told the Hardys that her brother, Morgan Thomas Todd, an instructor of foreign affairs at Kenworthy College, had disappeared.

"And I want you to find him, Mr. Hardy," Mary said pleadingly. "The police are working on the case, but have discovered no leads."

The girl explained that she was a freshman at Kenworthy College, which had just ended the spring semester. Her plan had been to spend the summer with relatives on the West Coast, but since her brother had disappeared several days before, she had canceled her trip and come to Bayport.

"I just don't know what to do, Mr. Hardy," she said. "Please help me."

Frank and Joe looked at their father. What would his decision be? He thought for a moment before speaking. "As I recall, your brother spent some time studying political methods in a foreign country."