"If only we knew where to start looking!" Joe said worriedly. "But we haven't a single clue to go on."

"The State Police are searching, too," Mr. Hardy told them. "A lead may turn up before the day is over. I hate to mention it," he added, "but the boys might have been kidnaped. So, to be on the safe side, there'll be absolutely no publicity."

"Good idea," Frank agreed.

For a minute he and Joe sat in glum silence. "What about the Sleuth?" Joe asked finally.

"The Coast Guard hasn't found it yet," Mr. Hardy replied, "and there are no leads on the bank robbery, either."

"How about the stolen car?" Frank queried. "Who owns it?"

"A man living up the coast," his father answered. "It disappeared day before yesterday while he was at a boat regatta in Northport."

"A boat regatta-" Joe murmured. "Where have we heard of one lately?"

"At the Coast Guard station," Frank prompted.

"That's it! Seaman Thompson thought the boat that tried to ram us might have come down from the regatta in Northport."

"Looks like Northport might furnish a lead to more than one mystery," Frank declared. "Let's take a run up there and see if we can pick up a due."

"If I go up the coast, I want to go in the Sleuth!" Joe answered firmly. "We must find her!"

At this point, Mrs. Hardy brought the discussion to an end by setting before each boy a stack of steaming, golden-brown pancakes.

Aunt Gertrude came in behind her with a block of yellow b.u.t.ter and a tall pitcher of maple syrup. "There are more cakes on the griddle," she said.

"You need your strength. And for goodness' sake, find those poor lost boys!"

"If we can help-" Mrs. Hardy began.

"Thanks," Frank said.

After breakfast the brothers hurried to the garage. "The bank robbers must have beached the Sleuth somewhere," Joe reasoned. "If we follow the sh.o.r.e, we're sure to find her."

The black-and-silver motorcycles backfired like pistol shots, then roared from the drive and down High Street. The riders headed out Sh.o.r.e Road, past the private docks.

The fog of the night before had given way to a bright-blue summer morning. As the boys sped along in a cool, salty breeze they watched the white sand of the beach on their right. There was no sign of the Sleuth.

Finally they reached the head of the bay and turned sharply, following the seacoast northward. For a while Frank and Joe saw only the big green rollers of the Atlantic as they broke into foaming white along the sand and rocks.

The brothers spotted the squatters' colony of slapped-together board dwellings ahead.

The cycles chugged up Sh.o.r.e Road, which rose and twisted along the top of high, rocky cliffs along the sea.

"Look down there!" Joe called out suddenly. He had caught the glint of sunshine on a familiar hull. The Sleuth! It was stranded on the beach!

"Yippee!" exclaimed Frank. "The robbers must have floated her in at high tide." The boys parked their motorcycles and hurried to the edge of the bluff. Below them, the rocky cliff fell straight down to the boulders bordering the sand.

"I don't see a path," Frank said. "Wait! Here's a place we can go down."

As he leaned over the edge, a ma.s.s of loose sod and stone gave way at his feet. With a startled cry Frank slid downward. Desperately he grasped for a hold, his clawing fingers closing on a sharp slab jutting out just below the lip of the bluff. His body hung a hundred feet above the rocks and sand below.

"Hang on!" Joe shouted, and whipped his extra-long leather belt from its loops. Lying flat, he inched downward over the cliff edge until he could pa.s.s the leather under Frank's armpits. He slid the end through the buckle and pulled the belt tight.

Joe squirmed back again, braced himself, and hauled. For one sickening moment Frank swung like a pendulum beneath the cliff. With all his strength, Joe jerked the belt again and a moment later helped Frank clamber to safety.

"Whew! That was close!" Frank said, gasping. "If it hadn't been for you-"

"Better leave the boat," Joe panted, retrieving his belt. "We can come by sea with the Coast Guard and get her." Still shaking from fright, Frank agreed.

The brothers went at once to the Coast Guard station on the pier. When Lieutenant Parker heard Frank's story, he called two men and led the way to a patrol boat. The powerful craft headed straight out the mouth of the bay and turned sharply up the coast.

The beach was a whitish line on their left. Soon it broadened, and the tumble-down buildings of Shantytown came into view.

"Wait! Wait a minute!" Frank called out. "Can we slow down? What's that white thing floating in the water?"

"A dead fish," suggested a Coast Guardman.

The patrol boat throttled down and slid nearer the object. Leaning far over the side, Joe lunged and scooped it from the sea.

"This isn't a fish!" he cried out excitedly. "It's a rubber mask turned inside out!"

As he spoke, his fingers moved nimbly. In an instant a limp gorilla face appeared.

"This belongs to Chet!" Frank exclaimed.

CHAPTER VII.

Dangerous Beachcombing FRANK took the mask from Joe and examined it carefully. "You're right. Here's the place where Chet ripped it at the party."

"But what's it doing floating in the bay?" asked Joe in great concern. "He and Biff must have gone out in a boat after all."

"But whose?" Frank queried.

"And why would they go out in the fog?" Joe added. Then he voiced the question uppermost in both their minds. "You don't think they could have drowned?"

Frank's face was grim. "Chet and Biff are excellent swimmers. Maybe, for a reason we don't know yet, they're hiding somewhere-perhaps Shantytown!" Frank gazed intently across the water at the squatter colony, now falling astern.

"Could be," Joe said. "They knew about our case. Maybe they picked up a clue and landed in Shantytown. We'd better find out as soon as we get the Sleuth."

The boys lapsed into worried silence until the Coast Guard boat came within sight of rocky cliffs towering high above the white beach.

A seaman scanned the sh.o.r.e with binoculars and sang out, "There she is, sir! It's the Sleuth, all right. I can read her name."

The engines of the cutter shuddered as it swung in toward the beached motorboat. The Hardys whipped off their shoes and leaped overboard into thigh-deep water as the craft crunched against the sandy bottom. Joe was the first to reach the derelict Sleuth.

"She looks okay," he called out to his brother.

"Yes, but high and dry," Frank said as he waded ash.o.r.e.

"We'll help you float her," a seaman offered.

Quickly gathering large pieces of driftwood, the boys improvised a crude skidway. Then, with the Coast Guardmen helping, they slid the boat down to the water. A towline was secured and the Sleuth bobbed toward Bayport in the wake of the Coast Guard patrol boat.

"Let's tow her straight to the boatyard," Frank suggested. "Maybe they have the new part by now."

His guess proved correct. While the patrol boat waited, the young mechanic quickly examined the Sleuth.

"Have you been using her?" he asked the Hardys.

"Well-somebody has, Charlie," Joe replied.

The mechanic nodded. "Hm-thought so. The temporary repair I made didn't last. But if you keep turning the wheel, you can make her steer a little-enough to get by."

"That's how the bandits slipped away in the fog last night," Frank whispered to his brother.

"I'll be finished in an hour," Charlie said. "Shall I have her taken to your boathouse?"

"Righto," Frank replied. "We'll pick her up there."

The Hardys rode on the patrol boat to the Coast Guard pier, thanked Lieutenant Parker and his men for their help, and hastened to their motorcycles.

"I wish the Sleuth were ready now," Joe said impatiently, "so we could go right to Shanty-town."

"But first we have to round up beachcomber disguises," Frank reminded him.

The boys rode home and changed into dry clothes. While Mrs. Hardy and Aunt Gertrude were preparing lunch for them, Joe called police headquarters. He learned that there were no new leads on their friends or the bank robbers.

Chief Collig was amazed to hear about the discovery of Chet's mask. "The boys may be nearer than I thought. I've already sent out a seventeen-state missing-persons alarm."

"We might find more clues in Shantytown," Joe told him. "We're going there next."

Directly after lunch, Frank and Joe bounded upstairs, pulled out some old shirts and pants, and hurried down again. As they pa.s.sed through the hall carrying the clothes, their mother and aunt looked out from the living room in surprise.

"Where are you going?" Aunt Gertrude inquired.

Mrs. Hardy asked, smiling, "Not another costume party? I returned your gorilla and magician suits this morning."

"Did you explain to Mr. French about Chet and Biff? He'll wonder why they don't bring their costumes back," Joe said.

"He wasn't there," Mrs. Hardy replied. "I left your outfits with the clerk."

"Where are you boys off to?" Aunt Gertrude demanded again.

"We're going sleuthing in Shantytown," Frank replied. "Probably we won't be home to supper."

Aunt Gertrude stared in disapproval. "Even foolhardy young detectives get hungry," she said tartly.

"I'll pack your supper," their mother offered. Aunt Gertrude and the boys followed her into the kitchen where the two women quickly prepared a package of food for the boys to take along.

"You and Auntie certainly move fast, Mother," Joe said admiringly. "Thanks a lot."

"Yes, we appreciate it," Frank chimed in.

Mrs. Hardy smiled. "We know you're in a hurry."

The boys went out the back door and hastily stowed the food and clothing in their motorcycle carriers.

"We must put in the make-up kit from the lab," Frank reminded his brother. With Fenton Hardy's help, Frank and Joe had fitted out a small modern crime laboratory over the family garage. Joe hurried upstairs to it and soon emerged with the kit, which he put in the carrier.

When they reached their boathouse, the boys found the Sleuth there. By the time the craft emerged, she carried two entirely different-looking young men.

Frank's face was smudged and his dark hair was tousled. He wore a battered straw hat and a striped jersey with a long rip in the back.

Joe's normal suntan had been made even darker by the use of make-up. A fake tattoo decorated his right arm. His trousers were torn off at the knees.

Both boys wore tennis shoes bursting at the sides. They carried burlap sacks appropriate for beachcombing.

"Let's land about a mile this side of Shanty-town," Frank suggested. "We can wander toward it along the beach."

Soon Beachcomber Joe, at the wheel, ran the Sleuth into a little cove. Drawing her up between two rocks, they camouflaged the craft with pieces of driftwood and dry seaweed.

"Now," said Joe, "if we can just find another clue to lead us to Chet and Biff!"

Frank nodded. "And at the same time learn what's behind the fighting in Shantytown."

Trying not to appear hurried, the two boys sauntered along with their sacks. The midafternoon sun threw a white sparkle over everything -the curling waves, the sand, and even the gray, bleaching driftwood.

Now and again Frank and Joe would stoop and put a handful of sh.e.l.ls, bits of rope, or a few pebbles into the sacks.

"Some beachcombing!" Joe grinned.

At last the Hardys entered the squatters' village. The first huts were merely tarpaulins stretched across driftwood poles. But as the boys strolled along, they saw that several of the many shacks were of wood, well constructed, with solid, padlocked doors.

A few men were lounging about, smoking. Frank and Joe pa.s.sed near a group roasting potatoes in hot coals before one of the huts. The men paid no attention to the Hardys as the boys moved on.

"If Chet and Biff are here, they could be in any of these shacks!" Joe muttered in a low tone. "How can we get a closer look?"

The young sleuths were walking between the water's edge and the first row of huts. Near them a man stood in the water wringing out a shirt.

"Let's drift up to the next shack," Frank suggested.