The Secret of Skull Mountain

by Franklin W. Dixon

  Instantly the boys flattened themselves on the ground behind some blueberry bushes. In the moonlight the man looked like a scarecrow.

  “There’s your hermit, Frank!” exclaimed Joe.

  He crossed the clearing and dumped his armful of fresh-cut firewood. After glancing cautiously around, he hurried to the top of the trail and looked down.

  Satisfied, the fellow returned to the load of wood he had dropped. He bent and tugged at something nearby, then lifted aside a large, squarish slab of rock.

  A narrow cleft showed black in the moonlight! Cradling the wood in his arms, the hermit stepped into the fissure and disappeared!

  CHAPTER XV

  The Escaping Stream

  FRANK AND JOE ran to the spot where the hermit had disappeared. They peered down the dark cleft in the mountaintop. There was no sign of the man.

  “This must be the source of the smoke!” Frank declared. “The rock is like a chimney cover.”

  The two examined the slab and saw that there was a handhold chiseled into the underface so that it could be moved from the inside to close the crevice.

  “This made a convenient escape hatch for Hawkins and his pal today!” Frank said.

  “It seems to be a tunnel,” Joe mused. “Wonder where it goes.”

  Frank lowered himself to the floor of the cleft. As Joe watched, he tested the slab to see how well it concealed the opening.

  “It’s perfect!” Joe told him.

  Frank seemed puzzled. “But for the smoke to come out, the crack has to be open—and then the cleft could be spotted easily.”

  “Sure,” his brother said. “But who’s to see it? Bob and Dick have no business up here. That leaves us, maybe Potato Annie—”

  “And Kleng’s gang,” Frank finished for him.

  With his flashlight, Frank stepped down farther into the narrow fissure and shot the beam ahead, A low passage sloped downward into darkness. “You’re right! It’s a real tunnel!” he declared.

  “Let’s have a look,” Joe said, dropping in beside his brother. He borrowed Frank’s light and played it on the irregular walls of the fissure. They were grimy with smoke smudges.

  “Let’s explore it!” Joe urged.

  “Okay. And find out where that hermit went.”

  One behind the other, the boys crept into the tunnel and crawled slowly downward into the darkness. Here and there the passage turned sharply.

  Suddenly Joe’s palm came down on a smooth cold object which rolled under his weight. With a startled gasp, he jerked back. The flashlight beam probed ahead, then shone directly on the object. It was a human skull!

  Joe let out a sigh of relief. “The hermit’s trademark!” he whispered.

  Frank chuckled softly, and the boys crawled on, with still no sight of the mountain man.

  Soon the long, narrow shaft turned sharply again. Joe shot the light ahead, then exclaimed in relief as he inched a few feet forward and stood upright. The passage had become large enough to allow the boys to walk side by side. They did not go far, however, before they were forced to stop.

  “The tunnel forks!” Joe said. “Now what do we do? And which way did that hermit go?”

  “Let’s try the left.”

  The broad passageway sloped downward, until the Hardys felt sure they had reached the very heart of the mountain. The air was damp but pure, and they breathed it gratefully.

  “Wonder where it comes from,” Joe thought.

  Down and down they went. Suddenly the tunnel leveled off, forming a small landing. Beyond, they could see that the shaft dropped sharply. The boys felt a swift current of air.

  Suddenly Joe grabbed Frank’s arm. “Listen!” he whispered.

  From the depth below came the rush of running water! The boys stepped to the edge of the landing and Joe aimed his light downward.

  Flowing through a channel at the foot of the shaft was a swift, bubbling stream. “It’s the water from the reservoir!” Frank exclaimed.

  “How do you know?”

  “It has to be!” Frank told him. “It’s flowing from the direction of the valley!”

  “Directions don’t mean much inside of a mountain,” Joe said doubtfully. “When we crawled through that passage, I lost track of which way is which.”

  “Well, it’ll be easy to check,” his brother declared. “We’ll come back here during the day. If the water isn’t flowing then, we’ll be pretty certain that the channel runs from the reservoir!”

  “Wait till Bob and Dick hear about this!” Joe said. “They’ll want to see for themselves.”

  Frank nodded. “I think we’d better head for camp and tell them about it.”

  The boys retraced their steps rapidly. When they reached the fork, Joe paused and said, “I’d sure like to know where this right-hand tunnel leads.”

  “Let’s walk in a little way,” Frank suggested. “This must be where the hermit went.”

  About a dozen feet into the passageway, Joe stopped abruptly. “Look!” he said. With his light he pointed to a piece of bark which lay on the ground. “That proves he came this way with his armload of wood!”

  “The tunnel must lead to the place where the wood is burned—probably a cavern,” Frank said. “I’d be willing to bet that’s the gang’s headquarters!”

  Joe grinned. “Let’s pay ’em a surprise visit!”

  “The tunnel forks!” Joe said. “Which way did that hermit go?”

  “No,” Frank said. “The two of us would be no match for the whole bunch.”

  “But we could spy on them and find out what their game is,” Joe persisted. “We might even find Dr. Foster.”

  “That’s quite possible,” Frank agreed. “But if they caught us, it would wreck the whole rescue operation.”

  Joe saw the point and the boys returned to the place where the tunnel forked and resumed climbing. Soon they dropped to their hands and knees and crawled into the low tunnel which led to the mountaintop. Joe went ahead with the flashlight, Frank following a few feet behind.

  The air was thinner and their progress slower. The boys were still some distance from the top when Frank stopped and began to sniff. “Joe—” he called.

  “I know. I smell it too.”

  Rising from the passage below them was the odor of wood smoke !

  Joe groaned, remembering the open fissure at the top of the mountain. “We called this a chimney, but we forgot what that means!” he said to himself ruefully.

  “Hurry!” Frank urged. “We must get out of here!”

  As the boys scrambled upward, the smoke became thicker. It wreathed around them, stinging their eyes and making them cough and gasp for air.

  The two crawled on, hoping that each turn in the shaft would bring them to the opening.

  Smoke now began to stream through the passage in a dense cloud. The boys clutched at their throats and coughed until they felt their lungs would burst.

  Suddenly Frank collapsed. His hands clawed at the rock floor, but his limbs were too heavy to move. The walls of the low tunnel seemed to be closing in on him!

  “Keep going, Joe!” he called hoarsely. He heard his own voice as if it were coming from a great distance. “I can’t make it!”

  He saw Joe turn. Then the flashlight spun out of his brother’s hand and the smoke-filled tunnel was plunged into darkness!

  CHAPTER XVI

  A Night Light

  HOW LONG Frank had been unconscious, he did not know. As he revived, his eyes still smarted from the smoke, but above him he could see a starry sky. A hand tilted a canteen toward his lips and cool water dribbled into his parched mouth.

  “Take it easy,” a voice said. “You’ll be all right.”

  Frank’s eyes opened wide. The speaker was Bob.

  “Where—? What—?” Frank began, then remembered. “Joe,” he asked anxiously, raising himself on his elbows. “Is he—?”

  Bob pushed him down gently. “He’s safe, too.”

  Frank sank back, relieved.
“How did you find us?” he asked after a few moments.

  “We saw the smoke when you and Joe started up the slope,” Bob told him, “and figured you were going to investigate it.”

  Dick added, “When the smoke disappeared and you didn’t return, we came up on the ridge to look for you.”

  Bob nodded. “We saw the open crevice and crawled in, but didn’t go far before smoke started to come up.”

  “It was lucky we saw your light before it went out,” Dick went on. “You weren’t far from the mouth of the crevice.”

  Frank smiled gratefully. Then, as Bob and Dick gave their attention to Joe, Frank looked about him. A short distance away smoke was still pouring from the open fissure.

  It was several minutes before Joe regained consciousness. By then Frank had gathered strength. He went to kneel beside his brother.

  “Oh, my aching head!” Joe mumbled.

  Frank nodded. “Guess that’s what happens to people who go exploring in chimneys!”

  Soon both boys declared they felt strong enough to make the descent to the camp. They moved slowly, their knees still weak. When the four reached the shack, Frank and Joe told the engineers what they had discovered.

  “You’ve found the channel!” Bob exclaimed. “That’s terrific!”

  “I think so,” said Frank, “and we’re pretty sure the gang has headquarters inside that mountain!”

  “It sounds possible,” Bob agreed. “But why do they want the water to run out of the reservoir?”

  “I don’t know yet,” Frank replied. “But at least we can make sure tomorrow whether the channel is the right one.”

  “Dick and I will go with you,” Bob said promptly. “But first we ought to get gas masks. We don’t want to be smoked out in that chimney!”

  “There are some gas masks in your office in Bayport,” Dick told him. “I stowed ’em there after our last field trip. Guess I’d better drive down and get them.”

  “We’ll do it!” Joe said. He explained that Fenton Hardy must be told of their suspicions about the hideout in the mountain.

  Bob gave the boys his office key. “How about hitting the trail first thing in the morning?” he asked.

  “Make it at sunup,” Frank said. “Joe and I will meet you at the top of the mountain!”

  Later, as the boys spun along the highway in their convertible, the cool night air cleared their lungs of the last bit of smoke.

  They stopped at Bob’s office to pick up oxygen masks, then drove through the streets of Bayport. The usually bustling business section was silent and deserted. It was almost midnight.

  As they approached Kleng’s shop, Frank slowed the car and the two looked through the plate-glass window. Swiftly Frank brought the convertible to a stop a few feet beyond the store.

  A light shone in the rear of the shop! The boys walked stealthily back to the window and saw that the gleam came from a transom over the door of Kleng’s office.

  Cautiously Joe tried the door of the shop. It was unlocked. He started to open it, but his brother seized his arm.

  “Hold it!” he whispered.

  Frank looked along the deserted street. In front of a fruit store a few doors away some empty crates had been piled at the curb to be picked up by the rubbish collectors.

  He carried the largest crate to the door and stood it on end. Then he climbed onto the box and pushed open the door a few inches with one hand. With the other he stuffed his handkerchief up into the bell, which tinkled every time someone entered the shop.

  “It can’t give us away now,” he whispered to Joe, and pushed the door wide.

  After quickly replacing the crate at the curb, the boys slipped into the shop, closing the door quietly behind them.

  The door to Kleng’s office was closed, but the transom was slightly ajar. The boys could hear a faint murmur of voices.

  Frank gestured to Joe, and they tiptoed toward the office. As they came to the end of the counter, they suddenly heard a muffled thumping.

  “What was that?” Joe whispered, startled.

  The noise came again. The boys leaned over the counter and looked down. Someone was lying on the floor, bound and gagged!

  Joe ran around the counter and turned on his flashlight. A pair of eyes looked at him appealingly. The prisoner was Chet Morton!

  CHAPTER XVII

  The Rear Room

  JOE UNTIED the rope which bound Chet’s hands and feet, while Frank removed the plump boy’s gag.

  Chet gasped. “Am I glad—”

  “Not so loud!” Frank cautioned him in a low voice, glancing toward the office.

  “How did this happen?” Joe asked softly.

  In a whisper Chet said that while returning from a late movie, he had decided to pass the plumbing shop to see if everything was in order.

  “I saw the light—thought I ought to investigate,” he went on. “The bell tinkled when I stepped into the shop and two guys came out of the back room and jumped me.”

  He looked at the Hardys quizzically. “How come the bell didn’t give you away?”

  Joe showed his handkerchief and Chet nodded understandingly.

  “Who are they?” Frank queried, nodding toward the rear room.

  “Sweeper and Limpy.”

  The three boys looked at the light in the transom over the closed door. Although they could hear voices, the sound was too faint for them to distinguish the words.

  Suddenly they became aware of a strange, hissing noise.

  Frank tiptoed to the door and looked through the keyhole, but the key was in it. Quietly he placed a chair beside the door, climbed up, and gently pushed open the transom a few more inches.

  Sweeper and the man with the limp were kneeling on the floor in front of a small iron safe. Sweeper was holding an acetylene torch, and its bluish flame was cutting a circle through the metal around the lock of the safe.

  Frank felt a tug at his trouser leg and looked down. Chet was eager to see what was going on.

  Frank stepped down and whispered, “Safe-cracking.”

  As Chet climbed onto the chair, both Hardys signaled him to be careful.

  Chet nodded reassuringly, then tried to peek through the transom. “I can’t reach!” he whispered. “Can you find me a couple of books to stand on?”

  Joe nodded reluctantly. He brought a few bound catalogs from the counter and Chet stacked them on the seat of the chair. He climbed onto them and teetered precariously.

  “Watch out!” Frank whispered sharply. He grabbed at the plump youth, but too late! Chet gave Frank a wild, despairing look as the catalogs skidded out from under his feet. He leaped to the floor, past the tumbling books.

  The boys heard exclamations from inside the office. The acetylene torch was shut off.

  Swiftly Frank lifted the chair away from the door, then he and Joe ducked behind the end of a far counter. Chet lay down where he had been before as if bound and jammed the gag into his mouth. The office door was flung open and Sweeper came straight to Chet.

  “Mmm. Okay. It wasn’t him.”

  “Then what was it?” asked Limpy from the doorway.

  Sweeper stared at the books sprawled near the upright chair. At that moment a large black cat walked into the rectangle of light which streamed through the open doorway. He stopped and looked at the two men, then meowed piteously.

  Sweeper laughed. “A snooping cat—that’s what it was!” he said, pointing. ‘Must’ve jumped on the chair and knocked ail those books off.”

  He picked up a book and threw it at the animal. The cat squalled and ran to another part of the shop.

  “Come on, Green!” Sweeper said impatiently. “We’ve got to finish this job.”

  Green limped after him and closed the door. Again there came the sound of the acetylene torch.

  Frank signaled a huddle, and the boys moved some distance from the door. “We must get word to Dad and Chief Collig.”

  But Chet shook his head. “Your dad’s in Chicago,” he whispe
red. “He got a phone call shortly after you left to pick up Joe at the grocery. He telephoned me and said to tell you he’d be back as soon as he could.”

  Joe groaned. “And we wanted to show him the tunnel and look for the hideout.”

  “We’ll have to handle it alone,” said Frank. He turned to Chet. “The convertible’s parked a few doors to the left of the shop. Drive to Chief Collig’s house and bring him here!”

  “Will do,” said Chet, and hurried out.

  The Hardys hastened back to the office door and Joe took up the watch. Several minutes later he saw the torch cut a complete circle through the metal of the safe. Its lock fell out onto the floor.

  Sweeper swung the heavy door open, reached into the safe, and took out a metal box. He snapped the lid up and dumped the contents on a desk.

  The thin man fumbled through some papers impatiently, then snatched an envelope. He drew out a roll of currency.

  “There it is!” he cried exultantly, flipping the bills with his thumb. “Five thousand bucks! Kleng’s promised me this cash ever since I started to do his dirty work, but he’s never delivered. Well, we’re square now, even if Kleng doesn’t know it!”

  Green wasn’t listening. He leafed nervously through the scattered papers, wetting his lips and muttering under his breath.

  Finally he drew out a bank check and stared at it. His fingers trembled. A look of triumph came over his face.

  “That it?” Sweeper asked.

  “Yes.” Green looked at Sweeper, his mouth quivering. “For years, Kleng’s been holding this against me,” he said. “I used to be a respectable accountant. I worked for Kleng. Then, to get more money for my family, I forged his name to this check.” He broke off and stared at the slip of paper. “Kleng threatened to have me sent to jail unless I helped him carry out his scheme. But now!” His voice was suddenly gleeful. “I’ll destroy the check and be free!”

  Sweeper laughed. “We’re both free, fella! You can forget Kleng and I’ll spend the five thousand!”

  Suddenly the boys heard a noise at the front door. Someone outside was fumbling with the handle. Quickly Joe stepped down, swung the chair aside, and ducked behind the counter with Frank.