“Eureka!” Chet shouted. “I was right!”
“How about letting us in on whatever you've found?” Joe pleaded impatiently.
“The top of this overgrown trunk,” Chet explained, “is attached by false rivets.”
“False rivets?” Frank queried.
“Yes,” his chum replied. “Actually they're not solid rivets, but are cut through in the middle and threaded so the ends can be screwed together just like a regular nut and bolt.”
The Hardys looked at Chet in amazement. “How did you happen to know about this?” Frank asked.
“When I began to study magic,” Chet replied, “I read a book about famous magicians. A few, like Houdini, were also great escape artists. The book described false rivets as one of the tricks they used.”
Chet continued to pound his fist against the knife. Soon the rivet head was loose enough to turn by hand. After several twists, it came apart.
“This is the hard way of doing it,” Chet said. “The escape artist uses a special wrench which fits over the rivet head. That's why these are shinier than the others.”
“Boy, your interest in magic really paid off,” Frank remarked with a grin.
“But why would Hexton lock us up in something we could escape from?” Joe asked.
“He never expected any of us to figure it out,” Frank surmised.
By this time Chet had loosened three of the rivet heads. Frank and Joe each took a turn working with the knife. The job was hard and tedious. Several hours passed before the last of the false rivets was unfastened.
Grinning in satisfaction, the boys pushed up against the metal top. It broke free and toppled to the floor with a loud bang. Elated, they quickly scrambled out of the trunk and stretched their aching bodies.
“Great going, Chet,” murmured Joe.
Frank echoed this, then beckoned the others to the door. The lock was, indeed, defective and the boys had no difficulty opening it. They stepped outside into a small vestibule. There they saw the entrances to several passageways.
“Leaping hyenas!” Joe exclaimed. “Which way do we go?”
“Golly!” Chet gasped. “Do you fellows remember which passage Hexton and his men brought us through?”
“I didn't realize there was more than one,” Frank admitted. “It was too dark to see.”
“This is like a maze.” Joe shook his head in bewilderment.
Using his flashlight, Frank led the others through one of the passageways, up flights of stone steps, through places where the ceiling was so low that they almost had to crawl, then along several sharp turns that completely confused them.
“We're not getting anywhere,” Chet complained.
“This castle must be honeycombed with secret corridors,” Frank said.
He swept his flashlight beam ahead and saw that the passage branched off in three different directions. They went down the middle one for what seemed like an hour, but could only have been a few minutes. It came to an abrupt end. They were facing a blank wall.
“Now what?” Joe sighed.
“What I wouldn't give for a road map of this place!” Chet mumbled.
The boys backtracked, then turned down the left passageway. More stone steps led them deeper and deeper inside the cellar of the castle.
Presently Frank stopped short. “Wait a minute,” he ordered. “Do you fellows notice anything?”
“Not me,” Chet said.
“I don'tâSay!” Joe replied. “The air is getting real damp and clammy!”
“Right,” his brother agreed. “Just like it was in the passage to Hexton's storeroom. Maybe we're on the right track.”
The boys continued on and made several sharp turns. Frank pointed his flashlight ahead and uttered a cry of dismay. They stood before the iron door to the storeroom, the very same place from which they had started!
At that moment they heard muffled footsteps. Frank snapped off his flash. From a distance, beams of light played across the iron door. The trio flattened themselves against the wall where it angled away from a little alcove.
Frank leaned closer to Joe and Chet. “It must be a couple of UGLI's to check on us,” he whispered. “Watch where they come from. It'll have to be the passageway that will lead us out of here.”
The men drew near. Would they see the escaped prisoners? Fortunately the men failed to notice the Hardys and Chet in the darkness and entered the storeroom.
“Hey!” came a shout almost immediately. “They're gone!”
By this time the boys had dashed down the corridor, along which the men had come.
“There they go!” one of Hexton's pals yelled. “After 'em!”
Frank, Joe, and Chet had a good head start. They ran as fast as the narrow, winding passageway would permit. Behind them swept the beams from the flashlights of their pursuers.
Ahead, the tunnel forked out into two flights of steps. “Oh no!” Joe cried despairingly. “Which way?”
Frank searched the steps with his flashlight. The ones on the left were more worn. “This way,” he said as the sound of the pounding feet behind them grew louder.
The three boys raced up the long flight of steps and down another corridor, but soon realized that their choice was wrong. The passage ended in a blank wooden wall!
“There
must
be a way out!” Frank declared. He picked up a loose stone and hammered against the wall. “Listen!” he said. “This wall doesn't sound solid. It must have a secret panel. Quick! Help me get it open.”
Joe and Chet pushed against the wall with all their strength.
“It won't budge!” Joe gasped.
The sounds of their pursuers' approach pounded in their ears. As the trio braced themselves for the oncoming struggle, there was a sudden grinding noise in the wall. They turned to see a panel slowly opening. A man, holding a flashlight, poked his head from behind the secret door. The boys' eyes widened in astonishment.
Kenneth Dell!
CHAPTER XIX
“Prepare to Ditch!”
“FRANK! Joe! Chet!” Great Circle's security chief exclaimed.
Behind him in a hallway stood Inspector Clyde. “I say!” he exclaimed. “What are you chaps doing in there?”
Before the three startled boys could reply, their pursuers rushed up. They almost collided as they came to an abrupt halt. Bug-eyed, Hexton's pals gazed at the lawmen, reinforced by other police. The UGLI's whirled about and ran back through the passageway.
“Come on!” Frank shouted. “After them!”
The boys rapidly gained on the men. Frank, in the lead, caught the nearest one with a flying tackle. He fell against the pair ahead, causing them to topple like a row of dominoes. There was a brief struggle while Inspector Clyde and several Scottish police officers rushed up to help the boys subdue their captives.
The UGLI men were handcuffed and led away by the police, while Frank, Joe, and Chet followed Dell and the inspector through the open panel into the main hall of the castle. They noticed it was already daylight, and Chet yawned sleepily as the group went to sit down in a huge library.
“We're amazed to see you, Mr. Dellâand you, Inspector,” Frank said. “How did you get in without being caught?”
“First, let me tell you why I came here,” Dell said. “SKOOL's work is paying off at last. Frank and Joe, your father has almost single-handedly cracked UGLI's operations in all European countries except the British Isles, and in the United States.”
“That's great!” Frank exclaimed.
“It sure is,” Joe added. “And the mystery of the undercover work here isâwell, half solved.”
Clyde said that shortly after dawn McHugh had telephoned him, fearful something must have happened to the boys. “I gathered a few constables together and came straight here.”
“Lucky break for us!” Joe remarked.
“At the castle gate,” Clyde continued, “we met a most unsavory-looking character. One of the constables recognized him as a thief wanted by the police in Glasgow. He resisted arrest and ran into the castle. We chased him.”
Clyde told the boys that inside he and the constables had encountered four other men who also resisted arrest. They were Arnold, Ross, and the twins.
“I questioned them,” he said, “but they refused to talk.”
“What about Hexton, Vordo, and Bleeker?” Frank asked.
“Apparently all three got away,” the inspector said. “Tell us, what happened to you?”
Joe briefed the men, then said, “I'll bet Hexton and the others are on their way to Edinburgh. Last night we overheard them discussing plans to steal the jewels at Nairn Loch Manor before it's opened to the pubâ”
Joe stopped speaking at the sound of a faint hissing and turned abruptly. Then he burst out laughing and pointed to Chet, who had fallen asleep in an easy chair. His hands were folded on his stomach and he snored lightly.
“You all deserve a good sleep,” Dell suggested, but the Hardys were too excited to accept the idea. There were still many questions to be asked.
“How did you find the entrance to the secret passageway?” Frank wanted to know.
Dell replied, “We were starting to search for you when a pounding sound came from the other side of the wall. All of us suspected it might be you signaling for help and hunted for a secret panel. I discovered that by moving the left gauntlet on one of the suits of armor in the main hall, a portion of the wall began to open!”
“And thank goodness,” said Joe. “We thought that wall was the end of the line for us.”
“Somewhere in this castle,” Frank spoke up, “there must be evidence of Hexton's espionage setup. Have you found it?”
“No,” Dell replied. “Haven't had time to look.”
“Let's see if we can find it,” Joe suggested.
No one had the heart to awaken Chet, so they left him. Inspector Clyde offered to investigate the library. Dell and the boys started down the adjoining hall to examine various other rooms.
The Hardys looked into several, but saw nothing to indicate espionage paraphernalia. At the end of the hall, they found themselves facing an enormous faded tapestry.
“Maybe this hides something,” Frank said.
He and Joe slipped behind the hanging and found a large double door which opened inward. As they entered, the Hardys were awed by the vastness of the room. The ceiling arched high above their heads, and lancet windows spilled bright sunlight onto the floor. At one end was a huge map of the world with colored pins stuck in various cities.
“UGLI's centers of operation!” Frank exclaimed. “If Dad missed any, this will tell him where else to look!”
In the center of the room stood two oak tables. There was an elaborate radio setup on one. Joe whistled. “Powerful baby!”
On the other table were several metal cases, sealed without any visible means of opening.
“Trick boxes,” said Frank. “One of Hexton's specialties.”
Dell walked in as the boys looked them over and tried pressure in several places. Nothing worked. Then Frank had an idea. He turned one box toward him and the side slowly opened.
Joe grinned. “Hardy, the magician!” “No,” said Frank. “Electric eye.” He moved the other two cases and each opened in the same way, revealing rows of drawers.
In the first one the boys found packages of microfilm and microtape, each labeled with a code tag.
“Tells where they came from and where they're going,” Frank guessed. “Hexton brings them here. UGLI operators make the pickup and take them to countries hostile to the United States and other democratic powers.”
Dell frowned. “These are probably films of secret plans and drawings of highly classified material.”
“Here's the roster of UGLI operators!” Joe exclaimed, riffling through a notebook. “Probably these names are in code.”
“Doesn't matter,” said Frank. He held up a red leather volume. “Here's the codebook!”
“Well,” said Inspector Clyde, entering the room, “that will come in handy when it's time to round up those UGLI blighters. I saw the tapestry hanging awry and guessed you might have found a hidden door.”
He stood in amazement at the boys' discovery. “What a treasure for Scotland Yard, the FBIâ”
“And SKOOL,” Joe spoke up. “UGLI, the biggest undercover subversive operation in the world, cracked wide open!”
Frank's enthusiasm was dampened by the fact that some of UGLI's top men were still at large. “Unless we catch them, they'll start a new operation somewhere else.”
“That's true,” Clyde said, and the others agreed.
“Then let's find them!” Joe cried.
At that moment a constable ushered in McHugh.
“I returned to Ianburgh to get my plane,” the pilot said, “and flew 'er back here. Thought I might be a wee bit o' help.” He had landed on an open field close to the castle, he told them.
“That's great!” Frank replied eagerly. “Will you fly us to Edinburgh?”
“Certainly.”
McHugh was introduced to Dell. The pilot grinned. “Man, ye got a couple o' fine detective lads here,” he said. “Well, I'm ready to start.”
Inspector Clyde decided to stay at the castle. “I'd better remain here in case something important pops up on this end.”
Frank and Joe roused Chet, who rubbed his eyes and stubbornly demanded breakfast.
“Come on!” Joe urged. “We'll grab a bite when we land. Chet, wait till you hear what we found!”
This roused the stout boy and he followed the Hardys and Dell to the plane. All the boys cat-napped during the flight, and later at Edinburgh Airport stoked up on bacon and eggs. Then, while McHugh stayed with the plane, the boys and Dell went to the local police office to reveal Hexton's daring scheme of robbery the next day.