54 His angry bellow carried across the water. He and his pal made no attempt to go after the boys, evidently realizing that they stood little chance against the Hai Hau's Hai Hau's husky and husky and determined crew.

"Wow! This is more excitement than I bargained for!" Jim Foy said. "Are you fellows sure those guys weren't real coastguardmen from the Bayport station?"

"We'll soon find out!" Biff declared.

He warmed up the transmitter again and tuned in the Coast Guard station frequency. All of the crew were much relieved when the base's radio operator a.s.sured them that no harbor patrol boats had been ordered to pick up unregistered craft. He also said that the lieutenant in charge would send out a launch at once to hunt for the troublemakers.

"I wonder where those fakers got their uniforms?" Tony mused.

Frank shrugged. "Stole them probably. What I'd like to know is why everyone's so anxious to get hold of this junk."

"Maybe all the guys we've had run-ins with are members of the same gang," Joe conjectured.

Biff offered another theory. He suggested that the two fake coastguardmen might be cronies of Clams Dagget. "Maybe Clams hired them to keep us from starting our boat business," Biff said. "You told us, Frank, that he sure was mad when he came to your house."

55 "That's right."

The Hai Hau Hai Hau returned to Bayport without further incident, and was tied up at the pier. returned to Bayport without further incident, and was tied up at the pier.

Jim Foy said he must leave as he had a job to do for his father. The other four boys remained for a while, talking over their plans. Tomorrow was to be the opening day of their pa.s.senger service to Rocky Isle.

"Let's keep our fingers crossed!" Tony said with a grin as the meeting broke up.

"Don't worry," Frank replied confidently. "I'll bet we get a full boatload every trip!"

Biff and Tony, who had ch.o.r.es to attend to, drove off in Biff's jeep. "See you tomorrow, fellows!"

"What'll we do now?" Joe asked his brother.

"Let's grab a hamburger," Frank said. "I'm starved."

"So am I. But first I want to phone the Coast Guard and find out if they've picked up those two fakers."

The brothers went into a nearby restaurant which had a pay telephone booth and made the call. The two men had not been caught.

As the Hardys perched themselves on stools, Joe suggested, "What say you and I try to trace those phony coastguardmen? Maybe we can spot their boat. After all, we got a good look at it."

"Smart idea! We'll take the Sleuth." Sleuth."

The boys finished their hamburgers and hur56 ried to the boathouse where they kept their motor boat. Minutes later, they were cruising along the sh.o.r.e of Barmet Bay. They went the full length of the three miles, first inspecting the north side, then the south. There was no sign of the speedboat anywhere.

"Let's try the ocean," Frank urged.

Leaving the harbor mouth, the Hardys turned northward along the coast. The ocean was as quiet as a pond. From time to time the brothers hailed fishing boats and other small craft to inquire about the speedboat. None of the skippers they questioned had sighted it, and the boys did not spot the craft hidden anywhere along the rocky, indented sh.o.r.eline.

"Looks as if we're out of luck," Joe grumbled.

Frank was keeping binoculars trained along the coast. "Let's try south of the bay," he suggested.

"Okay. Let's go!" Joe swung the Sleuth Sleuth around, leaving a frothing wake. around, leaving a frothing wake.

As it pa.s.sed Rocky Isle to starboard, a small cabin cruiser crossed their bow. The man at the wheel waved to them. Frank shouted a description of the speedboat and asked if he had seen it.

"Sure, about ten minutes ago," the yachtsman called back. "Heading over that wayl"

He indicated a sandy stretch of beach half a mile beyond the harbor mouth.

"Thanks!" The boys waved back.

57 "A break at last!" Joe muttered. He increased speed and the Sleuth Sleuth lunged ahead, its lunged ahead, its bow lifting clear of the water.

As they neared the beach which the yachtsman had pointed out, the boys switched places. Frank took the wheel.

"Hey, this is where Clams Dagget lives!" Joe remembered suddenly. He trained the binoculars on the sh.o.r.e, picking out Dagget's shack. "Frank!" he yelled excitedly. "I see those two men who pretended to be coastguardmen. They're standing in front of the shack, talking to Clams!"

Frank gunned the motorboat sh.o.r.eward. As it beached in the shallows of an inlet the boys leaped out and ran toward the shack.

At that instant their quarry sighted them. Breaking off the conversation with Clams, the two men dashed into the tall cattails behind the shack.

"After those fakers!" Joe shouted to Frank.

The marshy ground sloped upward into scrubby underbrush, willows, and sumac. Frank and Joe could hear the men plunging forward, but soon lost sight of them. The boys were finally forced to give up.

"What luck!" Joe growled. "We almost had 'em!"

"Let's see what Clams has to say about them," Frank suggested grimly.

Dagget was lounging in front of his shack, whit58 tling a piece of wood. He appeared unconcerned as the two boys walked up to him.

"Who were those guys?" Frank demanded.

"What guys?"

"The ones we were chasing."

Clams shrugged. "How should I know?" He be m m gan whistling airily as he continued work with his pocketknife.

"You'd better think hard!" Frank warned him. "Those fellows are-"

He broke off as a motor roared in the distance. A second later the boys saw their quarry's speedboat race from a nearby cove. It headed northward.

Joe clenched his fists in futile rage. "No hope of catching them with that kind of a start!

But I can notify the authorities on the Sleuth's Sleuth's radio. Wait here," he told Frank, and dashed radio. Wait here," he told Frank, and dashed back to the motorboat.

The young detective pressed the b.u.t.ton for the Coastal Search

59.

Coast Guard frequency. He reported having seen the impersonators and that they had taken a northerly route in their escape.

Meanwhile, Frank had been quizzing Clams 60 Dagget. When he found him unwilling to talk, Frank flushed with anger.

"Listen, Clams-I'm warning you. Those two guys you were talking to just committed a federal offense."

"What!"

The old beachcomber's mouth dropped open in a look of alarm.

"You heard me. They're impersonating members of the United States Coast Guard.

What's more, they tried to board our junk and take over," Frank added. "That could be attempted piracy."

"I don't know nothin' about "em," Clams Dag-get whined. "Never even seen 'em before.

That's the truth!"

"Then what were you talking to them about? You were sure acting chummy!"

"They said they wanted me to do a job for 'em," Clams replied. "I don't know what. You and your brother came along and scared 'em off before they got a chance to explain."

Presently Joe returned and questioned Clams further, but finally both boys decided he was telling the truth. Boarding the Sleuth, Sleuth, they returned to Bayport. they returned to Bayport.

It was almost seven o'clock when Frank and Joe arrived home. They found a note from Aunt Gertrude on the hall table. It said: I feel much better and am going out. Dr. Montrose is a good physician. He did not 61 talk about stocks and I had no chance to bring up the subject.

Phone Chet Morton's mother as soon as you get in. She has called twice. Frank Frank frowned. "I wonder what's up?" He dialed the Morton's number. A woman's voice answered almost immediately.

"This is Frank Hardy, Mrs. Morton. I-"

"Oh, thank goodness you got my message!"

Mrs. Morton sounded frantic. "Chet and the two girls haven't returned from their cave trip! They were due hours ago! Please help us find them!"

CHAPTER VII.

Missing Spelunkers.

frank tried to calm Chet's excited mother. "I'm sure there's nothing to be alarmed about, Mrs. Morton," he said soothingly. "Joe and I will start looking right away. Did Chet tell you where he and Gallic and lola were going?"

"That's just it-he didn't say exactly!" Mrs. Morton replied. "He did mention taking the West Road, but I don't know where. Oh dear, I never should have let them go!"

"Please don't worry," Frank said. "We'll find them."

As he hung up, Joe flashed him a questioning look. "What's wrong?"

"Chet and the girls are missing. Come on! We'll have to work fast before it gets too dark!"

The boys dashed out to their convertible and sped through the outskirts of town. Frank took the West Road. Outside Bayport, the road ran through a stretch of barren, rocky hillsides.

"Slow down," Joe said as they came to a turnoff. "Let's check this road. There might be a cave around here."

Frank braked the convertible and swung off onto the dirt shoulder. Joe leaped out, hoping to find the tire tracks of Chet's jalopy. He came back a moment later, shaking his head.

"No luck."

Most of the area was uncultivated, with scraggy brush and timber growing up the hillsides. As the boys rode along they pa.s.sed a rock quarry and several gravel pits. Here and there, dirt lanes branched off, leading to scattered farms or other roads.

The Hardys checked several of these rutted paths. On the fifth try, Joe shouted: "Hey! This may be it!"

Frank hurried to join him. His brother pointed out a set of narrow tire tracks with a worn, old-fashioned tread pattern.

"Those are Chet's, all right!" Frank confirmed. "I noticed the treads that time we helped him change one of his tires."

Hurrying back to their car, the boys turned up the lane. The convertible jounced and jolted so badly that Frank shifted into low gear.

Moments later, Joe gave a cry of relief. Chet's red jalopy was parked ahead. It had been pulled off the lane into a bordering clump of poplars. Beyond the trees, the ground rose steeply.

64 "There must be a cave entrance nearby," said Frank. "We'd better take our flashlights."

Joe grabbed them from the glove compartment and the brothers hopped out. Daylight was fading, but a clear trail of crushed undergrowth plainly showed which direction the spelunkers had taken.

The brush finally thinned out amid tumbled rocks and boulders. A few minutes' search, however, revealed an opening in the hillside.

Joe cupped his hands and yelled into the yawning darkness. "Hey, Chet! . . . lolal"

No answer.

"Let's go in!" Frank urged. "The cave probably runs in a long way. They can't hear us."

Crouching, the boys entered. Once inside, they were able to straighten up. Frank and Joe stabbed the darkness with their flashlights. The yellow glow revealed a fair-sized cavern, at least thirty feet in width. Straight ahead, the darkness closed in again beyond range of their flashlight beams.

"It's deep, all right," Joe muttered.

The boys pressed forward. Eventually the cave narrowed, then forked in two directions.

The right-hand opening dwindled into a crawlway of pitch blackness. The left-hand fork, though a cramped tunnel, was high enough for a person to walk through.