Their theory was quickly borne out as the sounds came in clearly, then faded again. The scrambler broadcast was evidently being transmitted more or less along the line which Frank had penciled.
“So far so good,” Joe concluded. “But how do we zero in on the source? All we know is that the beam runs between Bayport and the Willow River.”
“The Willow River!” Frank suddenly braked the car and reached for the map. “Joe, we’re a couple of dummies! Look here on the map. The answer’s staring us right in the face!”
“What do you mean?”
“Don’t you see where the beam intersects the river?” Frank jabbed the spot with his pencil. “That’s where the Lektrex plant is located!”
Joe’s lips puckered into an excited whistle. “Good night! Someone must be broadcasting from inside the plant! The spy who’s been spilling technical secrets to the gang!”
“Looks that way. But let’s check it out and make sure.”
After a quick scrutiny of roads on the map, Frank steered the car on a zigzag route that gradually brought them closer to the electronics company. Although there were slight pauses now and then in the transmission, as if two or more speakers were conducting a conversation, the boys managed to pick up the gibberish sounds almost every time their route crossed the beam.
At last they reached the River Road which ran directly past the plant buildings. Once again they were unable to hear the scrambler. Frank pulled off the road, near the main gate, and the two young radio sleuths listened for several minutes, but their transceiver remained silent.
Joe gave his brother a quizzical look. “The spy must have signed off.”
“I guess so.” Frank heaved a sigh of disappointment. “What a tough break, just when we had a chance of nailing him!”
“I’d better call Chet,” said Joe, “and let him know how we made out.”
He started to tune the transceiver back to their test frequency on a different band. But his fingers, twirling the knob, suddenly stiffened as a familiar voice came in faintly:
“This list covers all the engineers and technical employees working in the new wing, does it?”
“That’s Dad!” Joe gasped.
Jason Warner’s voice was replying:
“Yes. Of course there are the regular production workers to consider, but I think we can assume that none of them would have enough knowledge of the overall product to betray much to the spy ring.”
Frank stared in amazement as the radio conversation continued. “Straight voice now—without the scrambler. I don’t get it, Joe.”
“Maybe someone switched off the scrambler.”
“But this is over a different frequency!”
“Right! I’m goofing off again.” Joe scratched his head, utterly mystified. “Let’s backtrack and try farther away from the plant again.”
“Okay. Good idea.” Frank started the car, and after turning around, swung back up the dirt lane by which they had approached the River Road. The faint radio voices quickly faded.
As they angled across the path of the beam, Frank stopped the car and said, “Switch back to the 2-meter.”
Joe did so. Once more the gibberish sounds of the scrambler could be heard! Frank opened the door abruptly and got out of the car.
“Where are you going?” Joe asked.
“I have an idea.”
The dirt lane traversed an area of uncultivated field, overgrown with clumps of brush and occasional trees. By line of sight the distance from their present position to the spot where they had parked on the River Road across from the plant was only a few hundred yards.
Frank aligned his gaze approximately with the path of the radio beam. Then he strode across the field, cutting straight toward the plant. Joe watched and saw his brother finally come to a halt facing a gnarled old oak tree. Nearby it were several younger trees, still clad in withered brown leaves.
With mounting excitement, Joe saw Frank leap up and hook his fingers into a hollow opening in the trunk, to hoist himself off the ground.
Moments later, Frank lowered himself again and shouted through cupped hands:
“Come quick, Joe! I’ve solved the mystery!”
CHAPTER XVII
Window Bug
IN response to Frank’s call, Joe dashed across the brush-strewn field. “What did you find?” he asked eagerly.
“There’s some kind of radio rig inside this hollow oak. Here! I’ll boost you up so you can see.”
Frank held out clasped hands to form a stirrup for Joe’s foot. Putting one hand on his brother’s shoulder, Joe was hoisted up until his face was level with the hollow opening in the trunk.
“Wow! What a setup!” As Joe lifted his gaze, he gave another excited gasp. He had just noticed a cable protruding from another opening farther up the trunk. His eyes followed the cable upward.
“Frank, look!” Joe pointed to a small, square-horn antenna, positioned in a crotch of the tree and almost unnoticeable against the bark. “That’s what’s transmitting the beam!”
Joe dropped to the ground and faced his brother tensely. “The assembly in this tree must be a relay setup to catch the voice broadcast from the plant. Right?”
“Sure, the plant’s bugged with a hidden mike and transmitter,” Frank reasoned. “It broadcasts conversations from somewhere inside the buildings. I’ll bet this rig in the tree picks up the voice broadcast, amplifies and scrambles it, then beams it out at a higher frequency.”
Joe gave a quick nod. “So what’s our next move?”
“Dad must be at the plant right now,” Frank said. “We’d better go warn him and Mr. Warner pronto!”
The boys drove to the Lektrex Company and told the receptionist in the lobby that they must see their father. It was urgent. A guard took them to the executive conference room, where Mr. Hardy had been reporting to Jason Warner and his personnel manager the results of the lie-detector tests.
“What’s wrong, sons?” the detective asked.
For answer Frank put a finger to his lips, then wrote on a pad, “There’s plenty wrong. How long have you and Mr. Warner been talking in this room?”
Mr. Hardy wrote, “For the past hour. Why?”
“The room’s bugged!” Frank wrote. “We could hear your voices on the convertible’s short-wave!”
“What’s wrong, sons?” Mr. Hardy asked
Warner gaped in consternation as the Hardy boys took turns in writing their check on the scrambler and their discovery in the hollow oak.
“This is outrageous!” the president spluttered. He buzzed his secretary on the intercom. Before the Hardys could caution him to lower his voice, Warner ordered her to have an engineer bring detection equipment at once.
Within minutes the concealed “bug” had been located. Using a sensitive electronic probe, the engineer quickly traced it to a wooden valance across the top of the picture-window drapery. The bug had been mounted on a small rack screwed to the inside of the valance.
“It’s no amateur job, that’s a cinch,” the engineer said admiringly. “It’s one of the cleverest devices I’ve ever seen.”
He pointed out the delicate electronic components, nestled in a small crystal-plastic block. “This monosyllabic detector responds only to human voice frequencies. In other words, it turns the bug on only when someone is speaking—and a delay circuit turns it off again when the conversation ceases.”
“That’s to prevent power draining from the batteries?” Fenton Hardy asked.
“Partly that, and it lessens the danger of detection, too. If the bug were on all the time, there’d be too much risk of its being traced.”
Taking along a ladder, the engineer accompanied Frank and Joe to the oak tree in the field across the plant. He removed the radio assembly from the tree and they carried it back to the conference room. Battery-powered, it consisted of a receiver-transmitter, a compact frequency flip-flop type scrambler, and the small directional horn antenna which Joe had spotted, connected to the tra
nsmitter by coaxial cable.
“The bug itself is fairly weak,” the engineer explained. “It probably broadcasts only for a short distance outside the plant. This rig extends the broadcast range maybe up to four or five miles.”
Fenton Hardy nodded thoughtfully. “And I suppose by transmitting the signal in a fairly narrow beam they cut down the chance of it being monitored by the FCC.”
“FCC or hams, either one,” the engineer replied. “Of course this conference room’s used mostly at night. But if anyone did overhear the broadcast, as your sons did, the scrambler would keep them from guessing where it came from.”
“I can’t understand it.” Still flustered and mystified, Jason Warner paced about the room with a frown. “If this was the source of the leak, how did our Hong Kong rival get into production so fast? The bug can only have been here for a couple of weeks.”
“How do you know that, sir?” Joe questioned.
“I remember the drapes were dry-cleaned late in October and the valance was repainted at the same time. If the bug was here before, it would have been discovered.”
“Wait a moment!” Mr. Hardy put in tensely. “We’re forgetting the raid on the plant Saturday night. The bug may have been planted then, under cover of the robbery.”
Frank shook his head. “We know the bug was already in operation then. The first time Joe and I heard the scrambler broadcast was more than a week before the robbery.”
“Hmm.” The detective’s face took on a puzzled scowl. “In that case, there may be another bug that we haven’t found yet. Jason, you’d better have your engineers check over the whole plant-especially the new wing.”
The Lektrex president nodded. “I’ll attend to it right away. Meantime, I’d like you to run lie-detector tests on all our employees. Start with our custodial crew—janitors, maintenance men, and so on. One of them may have been bribed to plant the bug.”
Next day in the school lunchroom Frank and Joe were startled to hear their names called over the public-address system. The boys hastily finished their meal and hurried toward the principal’s office.
“Wonder what’s up,” Joe murmured uneasily.
“Don’t know. I sure hope everything’s all right at home.”
To their surprise, Fenton Hardy was waiting to see them.
“Dad!” Frank exclaimed. “Is anything wrong?”
“Yes and no.” Mr. Hardy gave a quick, reassuring smile. “How would you two like to handle an out-of-town job for me?”
“Great!” the boys chorused, and Joe added, “What’s it all about?”
“Tell you on the way. Get your things and let’s go. I’ve already taken the liberty of having you excused from the rest of your classes.”
As the three strode through the hall, the investigator said he had had a sudden call frcm the Noltan Medical Company, a drug firm in Philadelphia. “The formula for a new wonder drug they’re producing has leaked out. A German firm has just put an identical product on the market.”
“Another Aardvark spy job?” Joe blurted.
“Looks very much that way,” said Mr. Hardy, “though, of course, there’s always an outside chance that it’s pure coincidence. I told John Noltan, the president, that my regular operatives and I were tied up here, but that I’d send you two to get the facts from him.”
Frank flushed with pleasure at his father’s confidence, but asked a bit uncertainly, “Did he object? To your sending us, I mean.”
“Not at all. He’s heard of you, and I told him you’d been working with me on a similar case here in Bayport.”
Mr. Hardy had already booked two seats on a one-thirty airline flight. The boys drove to the airport, left their convertible in the parking lot, and were soon boarding a sleek jet. An hour later it landed at the Philadelphia airfield.
Frank and Joe caught a taxi to the modernistic plant of the Noltan Medical Company. Mr. Noltan, a burly man in a tweed suit, greeted them with a firm handshake.
“I assume your father has told you about our pirated drug formula,” he began. “Please sit down and I’ll—”
Noltan broke off abruptly in midsentence. “Is something wrong?” he queried.
The boys were staring past him, startled looks on their faces!
CHAPTER XVIII
The Shaggy Spy
“EXCUSE us for staring, sir,” Frank told Mr. Noltan. “I think my brother noticed the same thing I did—that head up on the wall.”
Frank gestured toward a huge, horned bison’s head mounted on a wall plaque. The animal’s glittering eyes seemed to stare out broodingly from under its dark furry topknot, and a woolly beard hung from its chin.
“You see, stuffed animals have kept cropping up in our investigation back in Bayport,” Joe explained. “It seems odd to find one here, too.”
“May we take the head down from the wall and examine it?” Frank asked.
Mr. Noltan gave the boys a puzzled smile. “Very well, if you think it’s important. I must say, I fail to see the point.”
The Hardys managed to unhook the plaque and lift down the heavy head. Then Frank pushed aside the bison’s beard and fingered the throat fur until he laid bare a row of stitches.
Joe gasped. “The same kind of workmanship we saw on the stuffed fox!”
Frank glanced up at the president of the drug firm and inquired, “Have you ever heard of a man named Elias Batter?”
Noltan shook his head. “Never.”
“Where did you get this bison, sir?” Joe put in.
“It was presented to me by a friend.”
“Was his name Afron?”
Noltan’s jaw dropped in astonishment. “That’s the man! Nils Afron. But how did you guess?”
“There was a stuffed fox stolen from the Lektrex plant in Bayport,” Joe explained. “That animal was given to the president of the company by the same person, Nils Afron. Frank and I tried to check on him in New York but—”
“The Afron I know is an interior decorator,” Noltan broke in. “He specializes in business office work. Let me see—I have his card right here.” Noltan drew out a wallet, leafed through its contents, and handed a small business card to Joe. “There’s his address.”
“That was his address, sir,” Joe said. “Frank and I learned he went out of business.”
Noltan stared at the boys, utterly mystified.
“We’ve been working on the theory that one of these animals may have something valuable hidden inside it,” Frank said. He shot a quizzical look at his brother. “But I think now we both have a different hunch.”
“We sure do!” Joe said eagerly. “May we open up this bison head, Mr. Noltan?”
“By all means! I don’t know what you hope to find, but I’m just as curious as you are!” He handed Frank a pair of desk shears.
In a few minutes Frank had sliced through the stitching and the inner shell, and was probing inside the bison head. Suddenly his eyes flashed with excitement. When he withdrew his hand, he was clutching a compact electronic assembly! The boys’ hunch had been correct!
Noltan stifled an angry gasp. “Is that gadget what I think it is?”
“If you mean an electronic bug,” Frank replied, “you’re right. This bison has been eavesdropping on everything said in your office.”
“Where did you meet Afron, sir?” Joe queried.
“On a hunting trip in Northern Canada.”
“At the Lachine Hunting Lodge on Lake Okemow?”
Noltan nodded bitterly. “You seem to know the whole story.”
Frank said, “And later Afron came to visit you here and gave you the buffalo head?”
“Yes, he stopped in once when he was passing through Philadelphia.” Noltan’s face was red with rage at the way he had been tricked. “I assumed he was angling for a decorating job—but it seems he was after a bit more than that!”
“You’re not his only victim,” Frank said sympathetically. “The president of Lektrex was fooled the same way.”
�
��It’s probably Afron’s regular method of operation,” said Joe.
Noltan frowned. “But I thought you said a stuffed fox was stolen from Lektrex. If so, how do you know it was bugged?”
“We don’t, but it’s a pretty safe bet.” Frank told about the Saturday night raid on the Lektrex plant, and the finding of a newly planted bug behind the window valance. “Chances are the new bug was installed during the robbery to replace the old one inside the fox.”
Joe snapped his fingers. “And this makes better sense out of the code message, Frank!”
“How do you mean?”
“Don’t you see? The message said: Raid Lektrex plant new setup. We thought it was all one sentence, meaning to raid the new plant wing. Actually it was two sentences, meaning to raid Lektrex and to plant a new bug!”
“Wow! That must be it, all right!” Frank paced about, unable to control his excitement. “Mr. Noltan, may I use your phone? I’d like to report to Dad right away.”
Noltan smiled wryly and gestured toward his desk. “It’s the least I can do after the fast way you two have cracked this case!”
“We still don’t have Afron and his gang, sir, but I’d say we’re one step closer.”
Frank dialed the long-distance operator and succeeded in reaching his father at the Lektrex plant. Mr. Hardy was thrilled over his sons’ successful detective work.
“You and Joe have done a great job! I’m proud of you,” he told Frank. “The first scrambled broadcast you picked up must have come from the bug in the fox, and the code message confirms that the new bug was planted during the robbery—so we can call off the lie-detector tests.”
Mr. Hardy added that the boys should leave any search for a scrambler near the Noltan Medical Company to the Philadelphia police and the FBI.
“By the way, Dad,” Frank asked, “is Chief Collig taking any steps to find the gang’s listening post in Bayport?”
“Yes, he has squads of police out combing every block in town within the path of the radio beam. But as you know, that covers a lot of territory. The search may take days. I’m not too hopeful, especially since the gang must know we’ve discovered the bug.”
The Short-Wave Mystery Page 10
