Mr. Hardy had given his sons permission to use his car, but as they were about to step out of the backdoor, their mother stopped them. "Aren't you taking Chet some flowers?"

"Flowers?" Joe said. "Oh, Mom, of course not."

"Well, you should take the patient something," Mrs. Hardy persisted.

"You're right. How about a fruit basket?" Frank suggested.

Their mother nodded approvingly. "A good idea-cater to Chet's appet.i.te."

"He takes pretty good care of that himself," Joe said. "All right, we'll stop at the store on our way.'

The boys drove to the heart of Bayport, where they stopped at a fancy food shop. There the proprietor made up an attractive basket of fruit, covered with transparent plastic and topped by bright-red ribbon.

As they drove out of town over the country road to the Morton farmhouse, Frank and Joe discussed their next step in solving the mystery of the missing Morgan Todd.

"Dad thinks we should investigate Commander Wilson further, so we'll do it," said Frank. "Remember Todd's riddle of the word Rockaway. We still have more sleuthing to do around Honey-comb Caves."

"When do we start?" Joe asked impatiently.

"As soon as we visit Chet." Frank turned off the road into the driveway of the Morton home and parked.

Between them, the Hardys carried the large fruit basket into the house. They were met at the front door by Mary Todd.

"Oh, how gorgeous!" she said, admiring the colorful gift.

Mrs. Morton came downstairs and greeted the boys warmly. "I think Chet can see you now," she said, adding that Iola was out shopping.

Mary and the brothers mounted the stairs to the second floor. "I hope he's feeling better," Frank said.

"He's quite comfortable," Mary said. "That poor, brave boy!"

When they entered Chet's room, Frank and Joe looked about, amazed. His bed was flanked by two bouquets of flowers. On the nightstand lay a half empty box of chocolates and a quart bottle of raspberry soda, four-fifths consumed.

Reclining on three fluffed pillows lay Chet, with a cherubic look on his round face.

"Hi, fellows," he said feebly with a wave of his hand. "How's tricks?"

"Jumpin' catfish!" Joe exclaimed. "You got the best trick of all. How about it, Frank, let's get ourselves blasted too?"

"It isn't any fun," Chet said, and with a look of pain held his hand to his forehead.

Instantly Mary Todd sprang to his side with a cool, damp cloth which she placed over his brow. "You poor dear," she said, and Joe gulped.

Frank stifled a grin. "We're going back to the caves," he announced. Chet's reaction was startling. He whipped off the compress and sat up.

"You are? Take me along, will you? That fishing was great!"

"We're not going fishing-not for fish, that is," Frank said.

"More sleuthing? Ugh!" Chet groaned and sank back on the pillows.

"Well, now that you're a celebrity," Joe said joshingly, "enjoy it while you can, Chet old boy."

This seemed to revive the chubby patient. "May I have another drink of soda, Mary?" he asked. His young nurse nimbly moved to the other side of the bed and poured a gla.s.s of the sparkling beverage.

Chet drank it and lay back again. "Yes, I guess I am a celebrity, fellows. The reporter got my personal story this morning."

"Reporter?" Frank said quickly.

"Yes," Mary put in, "from the Bayport Times."

"Mary made a big hit with him," Chet went on with a grin. "He asked a lot of questions about her, too."

"Wait a minute," Joe said. "What was this fellow's name?"

"Otto Lippincott." Mary supplied the answer.

"I never heard of anyone by that name on the Times," Frank said.

Frank excused himself to make a phone call and hurried downstairs. He returned ten minutes later, his face flushed with excitement.

"There is no Lippincott who works for that newspaper," he said. "Chet, you've been duped "

Disappointment, then indignation, crossed Chet's face. "Do you mean that guy was a phony?" he blurted.

"Nothing else but. He came here to fish for information," Frank replied.

Joe turned to Mary and asked, "How much did you tell this man?"

"Oh, have I done the wrong thing again?" Mary wailed.

"Well, maybe," Frank declared. "But it's too late to worry over spilled milk. From now on I advise both of you to keep mum on anything you know."

Just then the front screen door slammed and Iola's cheerful voice floated up the stairs. "Frank, Joe. Are you here?"

Joe blushed a little. "Yes, Iola, come on up."

Quick footsteps sounded on the stairs and Iola hurried into Chet's room. In her hand she held a white envelope. "I found this in the mailbox," she said. "No stamp or anything. It just says 'Chet Morton'."

"Another well-wisher, I suppose," Chet said importantly, and took the envelope. He tore off one end, blew into the slit, and removed the note.

"Good grief! Listen!" He read, " 'Get Hardys off case or your life will be in danger.' "

Iola gasped and clutched Mary's hand. "Oh, this is terrible!" she cried out.

Frank frowned and bit his lip. "I didn't want to get your family involved, Chet."

"What'll we do?" Joe asked.

Frank's mind worked rapidly. "We'll get Sam Radley to stand constant guard on the house here," he said.

"After dark tonight we'll smuggle Mary to our house. Mother and Aunt Gertrude can stand watch over her there."

"I'll say!" Chet said. "I wouldn't want to be the one to cross your Aunt Gertrude's path."

A telephone call to the Hardy home confirmed Frank's protection plan, and Sam Radley, who fortunately was in town, told the boys he would report to the Morton farm.

When Mr. Hardy's operative arrived about noon, Frank and Joe excused themselves and returned home.

Frank telephoned Bayport Police Headquarters and notified Chief Collig about the impostor and the threat Chet received. Collig promised to dispatch a squad car to patrol the area during the night and relieve Radley.

"What about Honeycomb Caves?" Joe asked after his brother had finished the call.

"We'll tackle them tonight," Frank said. "As soon as we have Mary safely here."

"Shall we go in the Sleuth?"

Frank mulled over the question. Finally he shook his head. "Going by water is a good idea, Joe, but these crooks are keeping close tabs on us and would probably recognize our boat."

"How about using Biff's?" Joe suggested. "He says the Envoy just got a new motor job and it's in swell shape."

Frank phoned Biff immediately, and arranged to use his speedboat for the brothers' sleuthing adventure.

The Hardys thanked their pal, who kept his craft in a boathouse half a mile from the Hardys'. After supper Frank and Joe packed their gear to have it in readiness. Then they drove out to Chet's place.

"Is Mary ready to come with us?" Joe asked Iola as they stepped into the hall.

"Just about."

The Hardys heard footsteps on the stairs and glanced up to see a slim, handsome young man descending.

He wore dungarees, work jacket, and farm hat.

"Hey!" Frank cried out. "That's not a guy, that's a gal!"

Mary Todd grinned in her disguise. "Iola and I thought up the idea. Like it?"

"Terrific." Joe nodded approval. "You two have the true detective spirit."

Chet, who appeared fully recovered, now came downstairs.

"I thought you were still sh.e.l.l-shocked," said Joe with a sly look at their stout friend.

"Without a nurse I'm better already," quipped Chet. Then he took on a serious demeanor. "Now look, fellows, be extra careful of Mary, won't you?"

With a promise that they would, the Hardys left the Morton house and drove Mary to their own home.

Aunt Gertrude and Mrs. Hardy received the girl kindly, and showed her to the second guest room.

Biff Hooper arrived minutes later and drove the brothers to his dock. In a few minutes the two sleuths and their gear were aboard the Envoy. Joe started the motor.

"I checked the running lights," Biff said. "Everything is okay."

The Hardys thanked him and shoved off, with Joe at the wheel. The Envoy knifed through the waters of Barmet Bay, its sh.o.r.e front twinkling with lights. As the boys pa.s.sed the boathouse where the Sleuth was kept, Frank called out, "Throttle down, Joe. What's that light over there?"

Joe brought the Envoy about and saw a light flickering from the window of their boathouse. "Jeepers! I don't know!" He extinguished the running lights and crept quietly over the dark waters.

As they neared the boathouse Frank suddenly exclaimed in alarm. Smoke was seeping out from beneath the door. Their boathouse was on fire!

CHAPTER XVIII.

Searchlight THE wailing of a police siren drifted across Barmet Bay, followed by the clanging bells of a fire engine.

Now the window gla.s.s of the Hardy boathouse broke from the heat, and flames licked out, illuminating the water.

With one hand on the steering wheel, Joe reached over for the fire extinguisher clamped on the side of the Envoy. Throttle open, the craft leaped through the water until Frank called out: "Joe! Slow down."

"Why? Our whole boathouse will burn up."

"The fire department will take care of it." Frank had hardly spoken before an arch of water sprayed against the building and the flames were quenched.

As Joe slackened speed and circled about, Frank explained, "This blaze could have been set for two reasons. One, to keep us from using the Sleuth, and two-"

"I get you already," Joe said. "A diversionary action!"

"Exactly." Frank nodded. "If our enemies are up to something tonight, they'll want to pin us down in Bayport."

By now the smoke, too, had abated, and firemen raised the door of the boathouse. In the glow of their lanterns, the brothers could see that the Sleuth was still afloat.

"She may not be badly damaged," Frank said. "At any rate, we can't stop to see now. On to Honeycomb Caves, Joe."

Unfortunately, the Envoy did not have a ship-to-sh.o.r.e radio, as did the Sleuth. The brothers therefore could not communicate with their home, but knew that Mr. Hardy would be notified of the boathouse fire soon enough.

Joe snapped on the running lights again, and the Envoy purred through the rolling waves as its pilot guided the craft expertly along the coast he knew so well.

After the Envoy pa.s.sed a blinking buoy marking the entrance to Barmet Bay, the run south was nearly in a straight line. But even with smooth sailing, it was nearly two A.M. before the great cliffs loomed in shadowy silhouettes on their starboard side.

Joe throttled back, and the Envoy rocked in the waves as the young detectives discussed their next move.

"Let's cruise past the caves as close as we can get," Frank said. "After that, we can put in at John Donachie's dock."

Frank spelled his brother at the wheel, and, guiding the Envoy silently toward sh.o.r.e, the boys studied the Honeycomb Caves. The half-moon illuminated the sh.o.r.e just enough to make the dark cave openings look like the baleful eye sockets of a skull.