The white-jacketed proprietor bustled forward to bar the way. He was a rather sinister-looking man with a heavy beard.

  “You wish something to eat, senores?”

  “We’re looking for a man who’s wanted by the police,” Frank told him. “He came in here a few minutes ago.”

  “What did he look like?”

  “A big fellow in a striped jersey.”

  The proprietor bared his teeth in a wide smile. “You are wrong, señores. No one of that description has entered the restaurant.”

  “Suppose we look in the kitchen, just in case,” Frank suggested.

  The owner hesitated, then raised his voice slightly and said in Spanish, “Visitors coming to the kitchen.” To the boys he added, “Muy bien, señores. You may go in, if you wish.”

  He gestured toward the swinging doors that led to the kitchen.

  “Thanks,” Frank said crisply, and strode forward, ahead of Joe.

  But as Frank pushed the doors open, his face suddenly blanched in alarm.

  CHAPTER XIV

  The Unseen Enemy

  “LOOK out, Joe!” Frank yelled as he ducked to the floor of the restaurant’s kitchen.

  A sheet of boiling water flew at the boys, just as Joe dropped to his knees. Both boys barely avoided being scalded, as the water passed harmlessly over their heads.

  The burly cook who had thrown the water stood holding a huge empty kettle in both hands. Joe was white-faced with anger. He jumped to his feet, ready to fly at the man with both fists.

  “Why, you big—!” he exploded.

  Frank interrupted with a shout, “Look! There goes Abdul!”

  The man was darting out the back door. Frank and Joe started after him, but the stout chef blocked their way, saying, “Ah, I am so sorry about the water, amigos!”

  He stepped back with a look of dismay as he spied the tattoo of indelible pencil still visible on Joe’s arm.

  “Please, Beppo!” he trembled. “I did not mean to—”

  “Shut up, you fool!” the proprietor snarled.

  The chef’s words ended in a gulp, but he kept on staring at Joe with a strange look.

  “Who’s Beppo?” Frank demanded.

  The cook said nothing, pretending not to understand.

  “Maybe he’s my double,” said Joe.

  Once more the owner assumed his pleasant expression. “He is confused, señor. I fear this little accident has greatly upset him. And now if you will kindly leave—”

  “Not yet!” snapped Frank. “You two are mixed up in some kind of racket and we intend to find out what it’s all about. If you don’t want to tell us, maybe you’d rather talk to the police.”

  “The police!” Obviously dismayed by Frank’s threat, the proprietor suddenly became nervously polite.

  “I will tell you everything. That big man—he rushed in here and said he wanted to hide. And if we told someone called Beppo, who has a pineapple tattoo, or anyone else that he was here, he would kill us. So I gave you a lie. I am so sorry.”

  “But what about that hot water?” Joe asked.

  The cook spoke up. “The big man made me throw it. He held me at gunpoint—otherwise I would not do such a terrible thing!”

  Frank and Joe did not know whether to believe the story, but they could not refute it. Finally Frank said, “Okay. We’ll go now.”

  Both the cook and the proprietor looked relieved.

  Outside, Tony and Chet were waiting eagerly. The Hardys related what had happened.

  “You fellows should have crowned ’em both with that empty kettle!” Chet exploded indignantly.

  “What now?” said Tony. “Go to the police?”

  Frank shook his head. “Those men in there just might be telling the truth. Anyhow, we have plenty of other leads to keep us busy.”

  “How about that motorboat Abdul might have been signaling from El Morro?” Joe asked.

  “I’d say it was worth checking up on. With that blue color, it should be easy to spot, if it’s still in this area.”

  “Let me handle that end of it,” Tony suggested. “I’m really aching for a chance to do some power-cruising in these waters!”

  Back in Bayport, Tony owned a boat called the Napoli II, in which he spent most of his spare time.

  The boys took a taxi to the oceanfront. It was a beautiful day and the sea sparkled in the sunshine. The four sleuths ate lunch at a restaurant specializing in seafood, then Frank rented a trim little speedboat.

  “Oh, boy, I can hardly wait to take her out!” Tony gloated as he warmed up the motor.

  “We should stick in pairs to be on the safe side,” Joe said thoughtfully. Chet would accompany Tony.

  A few moments later the two boys put-putted out across the water. Frank and Joe returned to the hotel, eager to work further on the clue of the pineapple tattoo, and, if possible, to link it with the word Cabezona. While there Joe scrubbed the indelible mark from his arm.

  “Let’s talk to the hotel manager,” Frank suggested. They found him in his office and engaged him in conversation.

  “Does the word Cabezona mean anything to you?” Frank inquired.

  “It means a large head,” the manager responded. He looked at the boys quizzically. “Why do you ask?”

  “Is Cabezona ever used to mean a pineapple?” Joe questioned.

  The manager scratched his head in thought for a moment. “I don’t know,” he said. “But I suppose the word could be used when referring to a large pineapple. If you are interested in pineapples, a friend of mine could give you information on the subject. He is Juan Delgado and owns a pineapple plantation at Manati.”

  “We’d sure appreciate it if you could arrange for us to make a visit,” said Frank.

  “I will call him at once.”

  The manager put through the call and carried on a rapid, pleasant conversation in Spanish. When he hung up, he turned to the boys with a smile.

  “It is all arranged. He will expect you early this afternoon.”

  “Thank you,” said Frank. “You’ve been a great help.”

  The brothers went to a car-rental agency, and made arrangements for hiring a coupé.

  The attendant provided them with a road map of the island, saying, “Just follow the directions I have marked, senores.”

  The drive was thoroughly enjoyable, with a cool trade wind steadily blowing in from the sea. On their left, the blue-green mountains rose toward the cloudless sky.

  The lush coastal plain was dotted with waving seas of sugar cane, interspersed here and there with fields of pineapple planted in orderly rows.

  In places the road became hilly, with shade trees arching overhead. Some were flamboyantes, the flame trees with gorgeous red blossoms.

  “Things really grow here!” Joe said admiringly.

  “Like living in a flower garden!” Frank remarked. “Mother and Aunt Gertrude would love this.”

  Arriving in Manati, the boys inquired the way to the Delgado plantation and were told it was located a mile north of town. When they reached it, Senor Delgado greeted them cordially on the steps of his long, low white bungalow.

  “Welcome, amigos! I understand you have come to learn about pineapples.”

  “Yes, Senor Delgado,” Frank said as he and Joe shook hands with the man. “Cabezona pineapples.”

  The plantation owner drove the boys around, pointing out the fields of spiked plants in various stages of growth. Men were busy in one section cutting off huge pineapples with long, sharp knives. Then, after showing Frank and Joe the huge cannery, he took them into his office. A white-jacketed Puerto Rican boy brought glasses and a pitcher of iced pineapple juice on a tray.

  “And now, perhaps you would like to ask me some questions,” said Senor Delgado as they all sipped the fruit juice.

  Shooting a quick glance at his brother, Frank decided to take the plantation owner into their confidence. When the servant left, he explained that they were trying to solve a mystery.

  “We have an idea,” Frank said, “that a certain dangerous group in Puerto Rico may use a pineapple as a sort of insignia. Have you ever heard of anyone wearing a pineapple tattoo on his left forearm?”

  Senor Delgado shook his head. “I have never heard of such a thing, señores, but it is certainly possible.”

  Joe inquired if Cabezona were the name of a place somewhere in Puerto Rico. Again Senor Delgado replied in the negative.

  But the native servant, returning just in time to hear the question, interrupted politely, “Excuse me, senores, but I have heard of a small place called Punta Cabezona on the coast north of here. The people call it this because the land is thickly overgrown, and looks like a huge pineapple. It is near the La Palma sugar central.”

  “Sugar central?” Joe repeated as both boys tried hard to conceal their excitement.

  “A mill where the sugar cane is ground up and crushed,” Senor Delgado explained. “I have never heard of this Punta Cabezona, but I can at least give you a note of introduction to the owner of the central, and he can give you exact directions.”

  He quickly wrote the note, then the boys drove off. Some time later the mill came into view, in the midst of vast fields of sugar cane. A tall stack, jutting up from the mill’s corrugated iron roof, belched a steady plume of smoke.

  “The whole air smells sweet around here,” Joe observed.

  Frank stopped the car and they got out at a small building with a sign marked Office. Inside, they found the manager and gave him Senor Delgad’s note. After reading it, the man rubbed his chin and looked puzzled.

  “I am sorry, but I myself am new in this district. However, I am sure that my foreman, Rodriguez, could direct you to this Punta Cabezona. You will find him working the cane crusher in the mill.”

  The boys walked over to the main central building. Trucks and tractor-trains loaded with cane were drawn up outside. Huge cranes lifted the stalks and dumped them into a chute.

  Frank and Joe entered and found themselves in a dark bedlam of noise. Giant rollers ground the cane into juice, which was then pumped into hot, spinning kettles to be granulated into sugar.

  A flight of steel steps led up to a narrow catwalk. At the far end was an enclosed cab, where the operator controlled the crushers.

  “That must be Rodriguez up there.” Frank had to shout to make himself heard.

  The boys climbed the stairs and made their way along the catwalk, clinging to a slender handrail. They were fascinated by the scene below. On their left were the huge rollers. On the right there was a steep drop past the giant flywheel into a pit of churning machinery.

  Suddenly Frank and Joe were shoved from behind. Taken off guard, they lost their balance. With wild yells, the boys toppled over the left rail!

  CHAPTER XV

  Atomic Cargo

  As FRANK went over the railing, he managed to clutch an iron upright with one hand. Joe grabbed his brother’s belt. White with fear, the two boys hung dangling above the pit of sugar-crushing machinery!

  “Help! Help!” they shouted. But the thundering machinery drowned out their voices.

  Would Señor Rodriguez hear their cries in time to save them from a horrible fate?

  Joe reached up, and by stretching was able to grasp a bar and let go the belt. The boys’ last ounce of strength was ebbing fast when Frank saw a figure in tan work clothes running along the catwalk toward them.

  “Hang on, Joe!” he gasped. “Someone’s coming!”

  An instant later Frank’s wrist was seized in a strong grip, while another brawny arm reached down to grab Joe’s. Singlehanded, the foreman hauled the boys across the rail.

  By the time the Hardys were dropping weakly onto the catwalk, two other workmen arrived on the scene to lend a hand.

  “Santa Maria!” gasped the boys’ rescuer, who had turned pale himself. “Never have I seen such a narrow escape!”

  The men helped Frank and Joe down the iron steps and out into the fresh air.

  “Thank you. Thank you very much,” Frank said to the man who had saved their lives. “Are you Señor Rodriguez?”

  “Sí, I am Rodriguez,” the foreman replied. “And now do you mind telling me the reason why you came so close to killing yourselves?”

  Joe explained what had happened, adding that the boys had not seen the person who had shoved them. The brawny foreman exploded with anger. “If I get my hands on that killer, I will wring his neck!”

  Turning to the workers, he asked in Spanish if any of them had witnessed the incident. One man told of having seen a man run down from the catwalk and flee out the door. Through the mill window, he had seen him drive off in a car.

  Rodriguez said to the boys, “I can assure you none of my men would try such a hideous trick!”

  “I believe you,” Frank said quietly, then after a pause, he asked, “We came here to get directions to a place called Punta Cabezona.”

  “Ah, sí,” said Rodriguez. “It is about five or six miles from here, but the road there is rather rough.” He gave the boys careful directions, and expressed the hope they would meet again under pleasanter circumstances.

  Frank and Joe thanked him, then walked back to the central office. As they entered, the manager looked up.

  “Did your friend find you, senores?” he inquired.

  “What friend?” Joe asked in surprise.

  “I did not catch his name, but he was a very tall man with a large head. I told him you had just gone over to the mill.”

  Frank and Joe exchanged knowing glances. Abdul! But how did he know they were here?

  After telling briefly about their close brush with death, Frank asked if he might use the telephone to call Señor Delgado. The manager, distressed that he had unwittingly helped the would-be killer, hastily agreed.

  “I—I do not know what to say, señores!” he gasped.

  “It wasn’t your fault,” Frank assured him.

  The manager helped to put through the call, and Frank spoke to Senor Delgado.

  “This is Frank Hardy,” he told the plantation owner. “Did anyone come there looking for us after we left?”

  Joe saw his brother’s face tighten as he listened to the reply. When he hung up, Frank’s eyes were grim.

  “Well, that explains it,” he said. “Abdul must have trailed us to the pineapple plantation. He arrived there right after we left and said he had an urgent message for us. So of course Señor Delgado told him where we’d gone.”

  “He must be a bad enemy,” the manager commented.

  “We agree,” the Hardys chorused.

  Realizing that they were still in grave danger, the Hardys drove cautiously to Punta Cabezona. The dirt road twisted through palm groves and canopies of dense green vegetation. When the boys arrived, Frank stopped the car and they got out.

  “Easy to see how this place got its name,” he remarked, peering ahead.

  The spit of land, jutting out to sea, ended in a bulging mound. This was topped with bushy green foliage, which sprouted outward from the crown of the hill, giving the place the appearance of a huge pineapple.

  “But I wonder how it ties in with the gang,” Joe said with a puzzled frown. “The place appears to be deserted.”

  The boys strolled out on the tiny peninsula, and climbed the hill. Reaching the top, they poked about among the bushes and vegetation. But the thick underbrush showed no sign of having been trampled by human feet!

  The Hardys were baffled. “I was sure we were on to something,” Frank said, disappointed. “Let’s walk along the shore.”

  They encountered several natives on the way. When questioned, none of them could recall having seen anybody lurking around the point.

  “Why should a person go out there, señor?” said one old man in Spanish, shrugging his shoulders. “Without a machete to chop down brush, there is hardly even a place to sit down!”

  A few moments later a plane droned overhead. Frank looked up and noted that it was flying due north. Suddenly he snapped his fingers.

  “Cabezona N!” he whispered excitedly. “Say, Joe, that N might be a directional signal, meaning north of here. Maybe it leads to the gang’s hideout!”

  “In the middle of the ocean?” Joe questioned dubiously.

  “No! It could be some island north of Puerto Rico!” Frank explained.

  Joe was impressed by his brother’s theory. “Maybe you’ve hit it,” he admitted. “Well, locating it will be our next trip, I suppose.”

  Elated over the clue, the boys returned to San Juan. By the time they reached the hotel, it was seven o’clock. Tony and Chet had not returned yet.

  “They must be doing some real sleuthing,” Frank commented, a little worried.

  The Hardys waited a while, but finally went down to the hotel dining room. Frank and Joe, growing anxious about their friends, had little appetite for their meal. As they forced themselves to eat, they discussed the message which Abdul had flashed out to sea: “3-4-8-9-P-M-Skeleton.”

  “That ‘PM’ part sounds like a time signal to me,” Joe remarked.

  “Sure, but a signal for what?”

  Joe mulled over the problem. “Well, this is a shot in the dark,” he admitted, “but how about a rendezvous at the airport? After all, if the racket we’re investigating is the theft of air-freight shipments, there might be some flight coming in that the gang is watching for.”

  Frank nodded. “That makes sense.”

  After finishing their supper, the two boys sat in the lobby and waited another half hour for Chet and Tony, but they failed to appear.

  “I think I’ll phone the police,” Frank said.

  He put in a call and asked if any boat had been reported in trouble. The answer was No.

  “That’s a relief,” Frank told Joe. “But I’d feel better if Chet and Tony were here.”

  “I’m getting the creeps waiting,” said Joe. “Suppose we go out to the airport and look over cargo flights.”

  “Okay.”

  After leaving a message for their friends, they took a taxi to the field. On the schedule board inside the air-freight operations office all incoming flights were posted.