The Sinister Signpost Read Free Page B

friend.
    â€œI’ll make sure he does,” Mr. Morton said. “I’m getting rid of that old car right away.”
    â€œBut 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.
    â€œI’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?”
    â€œMy 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.”
    â€œWhat’s the name of the company, sir?” Joe asked.
    â€œExeter 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.”
    â€œDid you get a description of him?” Frank asked.
    â€œYes,” Alden replied. “He was tall, wore black rimmed glasses, and had a beard and mustache that looked phony.”
    â€œObviously a disguise,” Mr. Hardy commented.
    â€œI’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.”
    â€œLeaping lizards!” Joe interjected. “Maybe the stranger has the plans to your whole motor!”
    â€œWe doubt that,” Mr. Hardy said.
    Alden grinned. “Your father is referring to the precautions I have taken to prevent the plans from being stolen.”
    â€œWhat 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.
    â€œThe 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.”
    â€œSounds foolproof,” Joe commented.
    â€œThat’s what I thought,” Alden said. “Yet somehow specifications for my motor must be leaking out of the plant.”
    â€œSo 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.
    â€œNo,” he replied. “And just to be sure, I had them all double-checked.”
    â€œWhat 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