“It could be a prank,” Frank said.
“You might be right,” their father replied. “But I suggest we all be very careful.”
As the boys took comfortable chairs in their father's study, Mr. Hardy filed the mysterious warning and turned his attention to a thick dossier on his desk.
“I've been going over the information given me concerning the stock-fraud case,” he said. “Very interesting. I'm sure you boys would like me to fill you in.”
“We sure wouldl” Frank answered quickly as he and Joe pulled their chairs closer.
“I've already told you,” the detective went on, “that the worthless stock was sold in the name of the Costa QuÃmico Compañia.”
The boys nodded.
“According to this information, the plan to start the chemical firm was the idea of Señor José Marcheta, a retired chemical engineer and a highly respected resident of Vivira, Mexico.”
“What made a man with his reputation go wrong?” Joe queried.
“That's just it!” the detective answered. “The facts indicate that Marcheta is not really part of the fraud.”
He explained that the engineer was sincere in his efforts to create a firm for the refining of chemicals. His principal aim was not only to develop one of Mexico's great natural resources, but to bring work to the people of the area. It appeared, however, that Marcheta had become the target of extremely clever swindlers, who used his efforts as a front for a stock fraud.
“What does Senor Marcheta have to say about all this?” Frank asked.
“He was questioned by the United States consul in Guadalajara, Mexico,” Mr. Hardy explained. “He denied knowing anything about the scheme, or any of those involved.”
“But he must know something about the men behind the plot,” Joe insisted.
“I'm sure he does,” Mr. Hardy agreed. “Nevertheless, Marcheta isn't saying anything. And it's obvious why. The consul's report states that he appeared badly frightened. Whoever's behind the fraud must have come up with a strong enough threat to keep him from talking.”
Frank and Joe mulled over the situation until bedtime. The next morning, Sunday, was chilly and rainy. The boys planned to do nothing more that day than to attend church, catch up on their reading, and ponder the mysterious events of Friday and Saturday.
After a leisurely dinner, the Hardys began to skim through the voluminous Sunday newspaper. Joe burst out laughing when he saw that Chet's water-kite escapade, complete with pictures, had made page two.
Frank was scanning another section when he suddenly sat bolt upright. “Wow!” he exclaimed, and quickly tore out a small news item. “Take a look at this!”
Joe's eyes widened in amazement at what he saw. The news story, datelined Mazatlan, Mexico, read:
A local fisherman has reported sighting an unknown submarine off the Sinaloa coast, approximately 140 miles northwest of Mazat-Ian. The sighting, according to police here, took place on Friday, but the report was not released at that time, pending an investigation by the Mexican Coast Guard.
Questioned by the authorities, the fisherman described an insignia painted on the conning tower of the craft. In his words, it “appeared to be flames issuing from a bundle of sticks, with the letter P in the center.”
A spokesman for the Coast Guard said that a search revealed no evidence of a submarine in the area.
“It sounds impossible!” Joe said as Frank dashed to get the broken ring he had found in Cardillo's car. The boys showed it to their father, along with the clipping.
The detective was amazed as he examined the ring. “Why, the design is similar to the one the fisherman described!”
“Exactlyl” Joe exclaimed. “There must be some connection between Cardillo and the sub. Maybe he escaped in the one we saw in the bay.”
“Now hold on a moment,” Frank said. “If Cardillo did escape from Barmet Bay by submarine, it couldn't possibly be the same craft the fisherman spotted. It would take weeks for it to sail there!”
“You're right,” Joe agreed. “But there could be more than one. What if Cardillo is a member of a gang that uses submarines?”
“Intriguing theory,” Mr. Hardy mused.
As they continued to discuss the mystery, the telephone rang. Frank scooped up the receiver. “Oh, hello, Chief Collig.... What's that you say?” Frank listened for a few seconds, his expression taut with excitement. “Okay, Chief. I'll tell him. Good-by.”
Frank whirled around. “Dad! Joe! Listen to this! The chief said that one of his men from the crime lab examined Cardillo's car for fingerprints. It was clean except for one clear specimen on the handle of the right rear door. The print belongs to Elmer Tremmer!”
“That's a tremendous clue!” Mr. Hardy cried. “This means Cardillo might have had something to do with Tremmer's disappearance!”
“Which suggests,” Frank added, “that Cardillo could be mixed up in the stock fraud!”
“But what about the submarine angle?” Joe said. “There are faster and easier ways of escaping.”
Mr. Hardy rested back in his chair to think. “I'm beginning to believe there's more to all this than a missing bookkeeper and the peddling of worthless stock,” he said finally. “Also, the various bits of information we've collected so far have one thing in commonâtheir connection with Mexico!”
Joe sighed. “That's a long way off.”
“True,” Mr. Hardy said. “But it might prove worth while for us to go to Mazatlan.”
“Us?” Frank cried out. “You mean Joe and me?”
“Of course. This is an important case. How about it, Joe?”
“Roger, Dadl”
“Señor Marcheta's home in Vivira is not far from Mazatlan,” Mr. Hardy went on. “I'd like to take a crack at talking to him myself. Perhaps I could get Marcheta to give me some useful information.”
“And Joe and I can check on the fisherman's story,” Frank suggested. “If we can track down the sub, you can be certain the trail will lead us to Cardillo ...”
“And Tremmer!” Joe interjected.
“Exactly what I had in mind,” Mr. Hardy said. “Your lead is strong enough to make it worth the try. But since I'm working with the investigators of the Securities Exchange Commission, I'll have to get their okay.”
Next morning Mr. Hardy made a telephone call to a man in New York. He then joined his sons at breakfast to tell them that he had been given the green light to go to Mexico. Frank and Joe let out a loud cheer.
“Fiddlesticks!” Aunt Gertrude snapped as she placed a heaping platter of hot wheatcakes on the table. “Rushing off to the ends of the earth again! I just don't know what to make of this family.”
“They're certainly on the go,” Mrs. Hardy said, serving the griddlecakes.
Joe laughed. “Mexico isn't so far off.”
“But enough to cause your mother and me a lot of worry,” Aunt Gertrude retorted. “I should think there'd be plenty for detectives to do right around here.”
Mr. Hardy planned to use his own sleek, single-engine airplane for the trip. He instructed his sons, both fliers themselves, to contact Jack Wayne, their pilot, to make arrangements. “Let's try to get off today,” he said.
Joe rushed to the telephone. Soon he had Wayne on the line.
“Mazatlan, Mexico, you say? Hold on while I get my air charts.” There was a brief silence, then the pilot's voice came on again. “As I see it, we'll have to make two refueling stops. The first at Memphis, Tennessee, and the second at Brownsville, Texas.”
“How long do you estimate the entire trip will take?” Joe asked.
“Roughly, about fourteen hours of flight time to Mazatlan,” Jack replied. “If we leave within the next couple of hours, we can be in Brownsville by eleven or twelve oâclock tonight, Texas time. Then we'll hole up there till morning. It'll not only give us a chance to get some sleep, but also we won't have to tackle those Mexican mountain ranges in the dark.”
“Good! We'll see you at Bayport field as soon as we pack.”
“One more thing,” the pilot added in conclusion. “Mexico requires that everybody have a tourist card to visit the country. Also, I'll have to file a special flight plan to Mazatlan. But we can take care of all that in Brownsville.”
Frank rushed into the room just as Joe finished his telephone call. “Guess what?” he said. “Dad suggested we ask Chet to go along.”
“Great idea!”
Chet readily accepted and received permission from his father.
The Hardys began packing. Finally they were ready to leave for the airport. Mrs. Hardy kissed her husband and sons as they said good-by. She was aware of the dangers involved in their work, but seldom allowed her concern to be known to them.
Aunt Gertrude shook her head dolefully. “No good will come of this! Mark my words!” she prophesied. “But please be careful,” she added, pecking the embarrassed boys on their cheeks.
Chet was ready when the Hardys drove up, and soon the group arrived at Bayport field. They found Jack Wayne seated in the plane. Within minutes the craft took off. The weather was exceptionally clear, and the terrain below presented a vivid picture in the sparkling sunlight.
The refueling was made without incident, and it was nearly midnight when the Hardy plane touched down on the runway at Brownsville. Jack and the others wasted no time checking in at a nearby hotel.
After breakfast the next morning they went directly to the Mexican Tourist Bureau to obtain their tourist cards. Jack Wayne filed the necessary flight plan to Mazatlan and soon the travelers were winging off on the final leg of their flight.
Frank and Joe were particularly awed by the country over which they were flying. Beneath them was a mixture of open plains and bleached deserts. Mountains jutted up on all sides, and some of these seemed to Chet to be higher than their own altitude.
As they neared their destination the group gazed down on a solid layer of stratus clouds.
“Looks like bad weather rolling in from the coast,” Frank observed.
Jack agreed. “I've been watching it. I'd better contact Mazatlan and see what's up.”
The pilot switched on the radio. It crackled for an instant, then was silent. He turned on the stand-by radio. Nothing! Jack tapped the radio compass and other navigational equipment vigorously. “Oh, nol” he muttered.
“Trouble?” Mr. Hardy queried.
“All our radios have gone out!” the pilot replied anxiously. “We must have a short in the electrical system.”
“And we don't know what the visibility is like below that cloud layer!” Frank declared. “If it's zero-zero, we'd have to make an instrument approach. That's something we can't do without our radios!”
“At least we're west of the Sierra Madre Mountains,” Joe commented. “We don't have to worry about running into those.”
“What about turning around and going back?” Mr. Hardy suggested. “The weather is clear east of the mountains.”
Jack turned and scanned the area behind him. “I'm afraid that's out! Take a look yourselves!”
The Hardys and Chet turned to see a frightening sight. Towering cumulo-nimbus cloudsâthunderstormsâwere already developing along the windward side of the mountains.
“We could never climb high enough to get over those storms!” the pilot said. “And to fly through them would be suidde!”
“Then we're trapped!” Joe exclaimed.
CHAPTER IV
The Hostage
FRANK frantically tried to get the radios working, while Jack Wayne flew in a continuous circle to maintain their position over Mazatlan.
“No good!” Frank finally declared, “We'll have to do the best we can without the radios!”
Chet groaned and Mr. Hardy looked grim. Jack suddenly straightened the plane out on a westerly course. “I'm going to try something,” he said.
“What?” Joe questioned nervously.
“The cloud layer doesn't extend too far out to sea,” Jack answered. “I'm going to let down over the water in the clear. From there, we can see whether there's enough of a ceiling for us to get into Mazatlan.”
The boys stared ahead as the pilot began his descent. After they had passed beyond the edge of the cloud layer, he dived the plane as low as he dared, then turned east toward the coast.
“We're in luck!” Frank exclaimed. “There's a ceiling of at least two or three hundred feet!”
“Yes,” Jack agreed. “But the visibility isn't too good. However, if we're careful, we should be able to make it. Let's hope it doesn't get any worse.”
The plane was now flying just above the surface of the water. Frank and the others peered ahead into the mist.
Suddenly Joe pointed off to his left. “I see something out there! Or is it just a band of dark clouds?”
The pilot leaned forward in his seat. “That's the coast of Mexico!” he cried jubilantly.
As they flew closer, various features of the terrain became more clearly defined. Frank unfolded a chart and compared the coastline they were approaching with the map profile.
“That wide inlet directly ahead, with a peninsula of land jutting out from the left, matches the shape of the coastline on the map where Mazatlan is located!” he exclaimed.
Gradually a sprawling city began to appear out of the mist.
“It is!” Mr. Hardy shouted. “Congratulations, Jack! You've hit it right on the nose!”
“Lucky again,” the pilot said jokingly. He rolled the plane into a left turn. “The airport should be a couple of miles north of the city.”