“When properly organized,” Frank put in, “it's a fine sport.”
“I call it utter nonsense!” Aunt Gertrude retorted. She hurried out of the room before her nephews could argue the point.
The next day the boys rose late. After eating a hearty breakfast and attending church services, they settled down to read the voluminous Sunday newspapers. Shortly the telephone rang. Frank scooped up the receiver. The caller was Iola Morton, Chet's sister.
“Chet won't be able to see you later,” she sobbed. “He's had an accident!”
Frank and Joe leaped into their convertible and drove to the Morton farm. They arrived to find the entire family standing on the front porch of the house. Chet was seated on the steps, exclaiming that he was all right. His face was blackened with soot.
“I don't need a doctor!” the chubby youth insisted.
“What happened?” Frank asked worriedly.
Mr. Morton, a good-looking, normally jolly man, turned to the Hardys. “Chet was experimenting with a highly volatile fuel on the engine of that old car I keep in the barn. He was pouring some into the carburetor when it suddenly blew up.”
“It seems the racing bug has bitten him,” said Iola, a slim, pretty girl. She was a witty, light-hearted person and was a school chum of the Hardys. Iola was Joe's favorite date.
“I was afraid something like this would happen,” Frank remarked. “However, I didn't expect it so soon.”
Mrs. Morton, an attractive, dark-haired woman, hurried to meet Dr. Mills, a Bayport physician, as he drove up to the house. He examined Chet, then left after saying that fortunately the boy had not been injured.
“You'd better call off your experiments,” Joe advised his friend.
“I'll make sure he does,” Mr. Morton said. “I'm getting rid of that old car right away.”
“But you can't!” Chet protested. “I'm on the threshold of producing the Morton super-duty racing car!”
Frank and Joe helped to convince him that such experiments should be left to the experts. Chet was crestfallen for a moment, then his face suddenly brightened.
“I'll drop the race-car project in favor of another idea,” he said. “A rocket-propelled bicycle!” The Hardys shook their heads in despair and returned home.
Monday morning found Mr. Hardy and his sons in Keith Alden's office. The company president was seated comfortably behind his desk, ready to discuss the case with them.
Frank was the first to speak. “Dad says that you suspect someone is trying to steal your experimental motor. Why?”
“My motor,” Alden replied, “uses a valve of a very unusual design. In fact, we're not equipped here at the plant to make one. However, I learned of a company on the West Coast that specializes in valve manufacturing. They said they could do the job, so I gave them the green light.”
He went on to say that one day Mr. Dillon, president of the valve company, had telephoned him excitedly. A stranger, who refused to identify himself, had appeared with the specifications of a valve exactly like the one to be used in Alden's experimental motor.
Keith Alden rubbed the back of his neck. “Beats me how the fellow got hold of my design.”
“What's the name of the company, sir?” Joe asked.
“Exeter Valve. It s a small outfit and, lucky for me, very reputable. Mr. Dillon told the guy he'd like to study the specifications further before agreeing to handle the job. The stranger refused and scooted off.”
“Did you get a description of him?” Frank asked.
“Yes,” Alden replied. “He was tall, wore black rimmed glasses, and had a beard and mustache that looked phony.”
“Obviously a disguise,” Mr. Hardy commented.
“I'm certain it was by sheer accident that the stranger went to the same company I was dealing with,” Alden declared. “And I'm also sure that his valve sketch was a direct copy of my own design.”
“Leaping lizards!” Joe interjected. “Maybe the stranger has the plans to your whole motor!”
“We doubt that,” Mr. Hardy said.
Alden grinned. “Your father is referring to the precautions I have taken to prevent the plans from being stolen.”
“What kind of precautions?” Frank asked.
Alden explained that there were only two sets of plans in existence. “One set, the original, is safely hidden. The other is recorded on film slides.
“The work is divided among the technicians here,” the man continued. “No one worker knows what the other is doing. Each receives his assignment in the form of a slide, which is placed in a burglarproof projector. He displays it on a small screen and uses it for his job.”
“Sounds foolproof,” Joe commented.
“That's what I thought,” Alden said. “Yet somehow specifications for my motor must be leaking out of the plant.”
“So far,” Mr. Hardy told his sons, “only half of the slides have ever been seen by anyone other than Mr. Alden. That's why we doubt that the entire design has fallen into the wrong hands.”
The boys asked Alden if he had the slightest reason to suspect any of his workers.
“No,” he replied. “And just to be sure, I had them all double-checked.”
“What about ex-employees?” Joe suggested. “Have you had any trouble in the past?”
Alden rubbed his chin dubiously. “Come to think of it, I did. But that was several months ago.”
He stated that Vilno Sigor, an engineer and designer, had worked in his research department. The man had created a number of small, but clever inventions which were used by the company.
“Then one day Vilno came to my office and accused me of picking his brain,” Alden said. “I told him that was what I was paying him for, and reminded him of the generous bonuses he received for his ideas. Vilno wanted more. He demanded a partnership in my firm. When I refused, he became furious and left. I haven't seen him since.”
“Too bad,” Frank muttered. “He might have been our man.”
“Now take his twin brother Barto,” Alden remarked. “He's still employed in my research department as a sheet-metal worker. An excellent craftsman. His job is to fabricate the bodies of our experimental race cars.”
“A twin brother?” Frank exclaimed. “That's a lead. Barto could be in cahoots with Vilno!”
Alden grinned. “You'd be wasting your time investigating him. He's the direct opposite of Vilno in engineering knowledge and in temperament. Even if he got a look at the plans of my motor, he'd never be able to understand them.”
Despite Alden's opinion of Barto, the boys were determined to list the sheet-metal worker as a prime suspect.
The young detectives asked about the two experimental cars that had met with accidents after their windshields had been mysteriously crazed. Alden told them that each of the vehicles was powered by a prototype of his motor.
“But whether the accidents were the result of sabotage, I can't say,” he added.
Mr. Hardy spoke up. “Right now let's tackle this case one step at a time,” he advised his sons. “We have to assume that somewhere in this plant there's a clever crook. He's managing to steal specifications of the experimental motor. Our first job is to find out who he is. And we'll have to find him fast!”
CHAPTER IV
Fingerprint Hunt
“So YOU want to work in my plant as undercover agents,” Alden said, when told about the boys' plan. “I like the idea.”
“Thanks,” Frank replied. “When do we start?”
“Tomorrow, if that's all right with you fellows,” Alden said. He glanced at his wrist watch. “I see it's nearly lunchtime. Let's have some food.”
After a delicious meal in the company's cafeteria, Alden conducted the Hardys on a tour of the plant. The boys watched with interest as various machinists turned out parts for the experimental motor. Each of the men worked from a plan projected on a small screen.
The last item on the tour was a visit to the research department. There Alden introduced the boys and their father to Barto Sigor.
“I am pleased to meet you,” Barto said in a quiet voice. He was a short, stocky man with bushy eyebrows and dark, wavy hair. His steel-gray eyes were fixed on the young detectives.
“These two lads will be working here in the plant for a while,” Alden told him. “They're taking an automotive engineering course at school and would like to get a little practical experience.”
“Ah,” Barto responded. “So you want to learn the automobile business. That's good. Do not hesitate to call on me if you have any questions.”
“We won't,” Joe answered.
Later, while driving home to Bayport, Frank and Joe discussed the case with their father.
Then Joe said, “What's your opinion of Barto, Frank? He seems pleasant enough.”
“I agree he's a weak suspect, butâ”
“You have something on your mind, son,” Mr. Hardy guessed. “What is it?”
“Mr. Alden said that Barto would not understand the motor specifications even if he got a look at the plans,” Frank replied. “However, since Vilno and Barto are twins, it's possible that they could have switched identities.”
“There's only one flaw in your theory,” Mr. Hardy said. “Vilno is not a sheet-metal worker. How could he perform his brother's job at the plant?”
“I didn't think about that,” Frank admitted. “Still, I'd like to check it out.”
“There's one way of settling the question,” the older detective suggested. “Try to get Barto's fingerprints. But do it without his knowledge. We don't want Barto, or anyone else in the plant, to suspect you're working on a case.”
The boys retired early that night. The next morning they started for the Alden plant immediately after breakfast. Mr. Hardy, who had been supplied with a microfilm report of all the employees' records, remained at home to check the information against his files on criminals.
The boys spent the morning watching the skilled machinists perform their various tasks. Finally they positioned themselves so they could peer into the research department to observe Barto. The young detectives noticed that he wore a pair of thin rubber gloves constantly. Joe made a casual remark about this to another mechanic.
“Barto always keeps those gloves on,” the man said. “He uses certain acids in his work. Also, he says the gloves give him a better grip on his tools.”
Eager to discuss the situation, the young detectives retreated to a secluded corner of the plant.
“Those gloves of Barto's make it impossible to get his fingerprints,” Joe commented.
“He'll have to take them off sometime,” Frank pointed out. “Maybe when he has his lunch.”
At noon most of the workers went to the cafeteria. Barto, however, did not leave the shop. Instead, he walked to a clothes rack in one corner of the room and pulled a sandwich, wrapped in wax paper, from the pocket of his jacket. He then sat down on a bench, removed his gloves, and unwrapped the sandwich. The boys watched from a distance.
“We might get a good print from that wax paper,” Joe whispered.
“Right,” his brother agreed. “Let's see what he does with it.”
After Barto finished eating, he crumpled up the wax paper, put his gloves back on, and strolled out of the shop through an exit door. The young detectives rushed to a window and peered outside. There they spotted the suspect walking toward a flaming incinerator. The man tossed the wax paper into it and returned to the shop.
“Well, that's that,” Joe muttered disappointedly.
“We can't waste too much time trying to get Barto's prints,” Frank said. “Let's follow him when he quits work for the day.”
A few minutes before five o'clock the boys hurried to the parking lot to pick up their car. Then they posted themselves outside the main gate. Workers began to spill out of the plant.
“There's Barto!” Joe said.
The boys watched their suspect walk to a street corner and wait. Soon a bus came along and Barto climbed aboard. The boys followed the vehicle. Eventually the trail led them to the center of Clayton. The bus stopped and Barto got off.
“We'll park the car and follow him on foot,” Frank declared.
They shadowed their suspect in the best detective fashion. Barto bought a newspaper. Then he stopped at a refreshment stand and ordered a glass of orange juice. When he had finished and walked off, Joe rushed to the stand to seize the glass. But before he could do so, a counter-man swept up the tumbler and plunged it into a sink filled with soapy water.
“Out of luck again,” Joe grumbled.
Finally Barto led the boys to a small, red-brick apartment house off the main street and entered the building. Frank and Joe waited a few minutes, then dashed into the lobby. They quickly checked the mailboxes and found that Barto lived in apartment 6B.
“Well, there's nothing more we can do today.” Frank sighed. “We may as well go home. Maybe we'll come up with an idea before tomorrow.”
After supper the young detectives joined their father in his study.
“Sorry to hear you haven't had any luck with your investigation today,” Mr. Hardy said. “Neither have I. So far, none of Alden's employees show up in my criminal files.”
“Did you check on Barto and his brother?” Frank queried.
“Yes, I have.”
Mr. Hardy said that according to their records, the twins had been born in a small Midwest community. When they were still very young, their father had moved the family to Switzerland, where he accepted a job as an engineer. It was there that Vilno attended a university, and Barto had learned the sheet-metal trade.