As Bold Island harbor was sheltered and the yacht could lay close in to the shore of Devil Island and be so hidden that she would escape observation to a large extent, Frank ran in there, choosing that anchorage in preference to the one in the cove on the other side of the island of mystery.

It was near low tide when Merry ran in there, and he did not stop till the keel of the White Wings stuck fast in the mud at the bottom.

"I thought you were getting in too near," said Hodge.

"Not getting in near enough to suit me," declared Frank. "The bottom is soft here, and the yacht would sit up straight in the mud if the tide ran out so that she was left high and dry. It is low water now. At high water she will float all right and have any amount of water under her keel."

As soon as everything was attended to on the yacht, Frank cried:

"Come on, fellows, let's row over to Bold Island and see if we can find some of her famous clams. We may not get another opportunity like this."

"Oh, what's the use," yawned Browning, sleepily. "Too much trouble. I'm going below and turn in."

"I will stay to look after the yacht while Browning gets his nap," said Hodge.

Diamond was ready to go with Frank, and Merry asked Hans to come along. They had purchased a clam hoe at the Landing, so they were prepared to hunt the shy and retiring clam.

"Vale," said Hans, sadly, "I vill go mit you, poys, but I don'd peen aple to took no bleasure mit der shob since I vos caldt an Irishman. I don'd pelief you vill efer got ofer dot."

He looked very sad and downcast, as if he were nearly, heartbroken, causing Merry to laugh softly.

The three got into the boat and pulled over to Bold Island, where they began searching for the clams that have made the island famous throughout Penobscot Bay.

It was some time before they could find any clams, for the beach had been dug over and over till it did not seem there was a place left untouched. At last Frank turned over a large, flat rock, and down in the sand beneath it they struck their first clam. That clam, measured in its shell, was exactly seven inches long and a little more than five inches wide, while the shell itself was almost as white as the shell of an egg.

When Merry turned up this clam, Hans staggered and sat down on the sand with great violence, and there he sat, staring and muttering:

"Vot der tyrful vos dot? Uf dot don'd peen der varter uf all glams, you vos a liar! I don'd pelief I efer seen anyding like dot pefore in all your porn tays!"

"Hurrah!" cried Merry. "Here's proof the fishermen down this way are not all liars, or do not lie about everything. They told me this was the kind of game we should find here."

"But this must be unusual," said Diamond. "Can't all of them be like this."

"They say so."

"Well, they cannot be very good to eat. They must be too tough."

"On the contrary, I have heard they are splendid eating. Here is another! By Jove, it's fully as large as the first!"

Hans sat still on the sand and stared straight at the first clam turned out. Frank looked at him and saw the Dutch boy appeared on the verge of bursting into tears.

"What's the matter, Dunnerwust?" he asked.

"I vos peginnin' to seen things queer," replied Hans. "Vot do I think? Vale, uf dot glam don'd look like der mug an Irishman of, you vos a liar! Uf I kept on seein' things like dot to remindt me vot dot man in gray said, id vill drife me to trink ur to sluicide!"

They had brought along a bucket, and it did not take long to fill it with these large clams. Then they emptied it into the bottom of the boat and found another bucketful before stopping. With those they returned to the boat.

"We will go ashore on Devil Island, where there are plenty of rocks of all kinds, and seaweed, and there we'll have a clambake," said Merry. "There is wood enough on Devil Island, too, and it is nearer to the yacht."

The sound of their oars brought Hodge on deck.

"What luck?" he asked, as they approached.

"Great luck," answered Frank. "Get in, and we will take you ashore over yonder, where we are going to have a clam roast."

The clam hoe was passed up to Bart, and then he swung down into the boat, and soon all were ashore on the island of mystery.

Frank began constructing an oven amid the rocks, sending the others for fuel and seaweed. It did not take long to make preparations for the bake, and soon a roaring fire was blazing, as a lot of dry wood had been found near the deserted camps on that side of the island.

Frank took the clams down to the water and washed them carefully, a bucketful at a time, turning them all into the hollow of a large rock near the fire.

As the fire grew hotter, Merry threw stones into it and kept it roaring. None of the stones were smaller than a man's fist, and some were larger than a man's head.

"Why are you doing that?" asked Hodge.

"You will see when the time comes," smiled Frank.

Hans sat on a rock and stared into the fire, his air of dejection being extremely ludicrous to behold.

"Come, come, forget it!" exclaimed Merry. "Cheer up and be like yourself."

"I can nefer peen like yourseluf again so long as I had this face onto me," sighed Hans. "Id peen a vrightful thing to think dot I might peen misdooken any dime an Irishmans vor! Dunder und blitzens! I vos all proken ub in peesness ofer dot!"

It was useless to try to cheer him up. The more they talked to him the sadder and more downcast he looked.

After a while Frank had burned out nearly all the wood, and nothing was left but a dying fire. He did not wait for it to die down, but raked away everything but the red-hot coals and some of the stones in the fireplace of stone. Then he took the wet seaweed and threw it into the fireplace, where it began to sizzle and steam.

"In with the clams, boys!" he cried, as he began to toss the big fellows in upon the seaweed.

They helped him, and soon all the clams were scattered on the steaming seaweed. Then he covered them with more seaweed, and, aided by the others, piled the hot rocks he had drawn out of the fireplace on top of this mass of seaweed.

What a sizzling and steaming there was, and what a delightful odor came to their nostrils! Quickly Frank had another fire going, and by this he kept hot a mass of rocks he had heated in the first fire, but had not piled upon the seaweed. In this way, by the time the rocks on the weed were cooled off, more rocks were ready to take their place, and the clams were kept steaming.

After a time, Merriwell announced that the clams must be nearly done. He sent Hans off to the yacht to bring Browning ashore. The Dutch boy found it difficult to arouse the big Yale man, but Browning was fond of clams, and he came along quickly enough once he was fully awake and understood what awaited him.

As the boat reached shore, Merriwell began to rake the rocks off the seaweed.

"Ye gods!" grunted Bruce, sniffing the air as he approached. "What heavenly aroma is this that greets my nostrils?"

When the clams were uncovered and he saw them with their huge shells yawning and the meat within looking white and tempting, he declared he was very happy to be living.

"Gather round, fellows," said Frank, "Capture your clams and devour them. There will be no ceremony in this case."

Then, as Browning fished out a clam and held it triumphantly aloft, a man came whistling softly down the bank, joined the group without a word, raked out a clam and extracted it from the shell, being the first to taste the feast Frank had prepared.

It was the man in gray, Mr. Caleb Cooler!

"Yum!" exclaimed the man in gray. "That clam is hot!"

"Well, you are cool enough!" said Frank Merriwell.

"Oh, I'm Cooler," chuckled the queer old fellow. "Told you so some time ago. Howdy, boys. Fine day, isn't it? Think we will have some more weather? Or don't you know 'weather' we will or not?"

Bruce Browning arose to his feet and removed his coat.

"That's one way to keep cool at a clambake," grinned the man in gray. "What are you going to do?"

"Mop up the beach with you," answered Browning, quietly. "I am going to teach you a lesson."

"Teach is correct as you applied it," said Mr. Cooler. "Down this way I find people say 'learn' for 'teach.' Just think how bad it would have sounded had you said you were going to learn me a lesson."

He raked out another clam, but dropped it, shaking his hand and blowing on his fingers.

"Even though I am Cooler, I find some things are warm enough," he murmured. "That clam must have been near a fire. I dote on clams, baked, boiled, fried or frizzled, it don't make a dern bit of difference. Whenever I get an opportunity I go gunning for clams myself. I think it is great sport to shoot a clam on the wing. With a good bird gun and a dog, I presume it is an easy thing to bag clams around here?"

He was not paying the least attention to the big Yale man, and Browning's threat to "wipe up the beach" with him seemed forgotten.

Hans was glaring at the man in gray, while strange, gurgling sounds came from his throat. All at once he gave a yell, rolled over backward and scrambled to his feet.

"Don't touch him, Pruce!" warned the Dutch boy. "I peen goin' to smash dot veller myseluf!"

"Ah there, Irish," chirped Mr. Cooler. "You will catch cold in your liver if you let the wind blow down your throat that way. Have a clam and let it stop that orifice in your countenance."

This made Hans so angry that he danced wildly and began to choke and gurgle in his endeavor to shriek forth something, but the man in gray did not even look at him.

There was something extremely ludicrous about it all, and Frank was forced to laugh. When he saw Merry laughing, Hans seemed to lose all his strength, and he dropped down on a rock, completely knocked out, even though he had not been touched.

Browning was grinning now, for he saw the humor of the situation, and he could not help admiring the nerve of the queer old fellow.

"Look here, Mr. Cooler," said Frank, "who invited you to help yourself?"

"Eh? Oh, why, I didn't need an invitation to join old friends like you chaps. I knew you would be glad to see me."

"We are," grunted Browning, "tickled to death."

"Then sit right up and take hold, boys," chuckled Mr. Cooler. "Catch your clam and peel him. We'll have a real jolly time."

He raked another one off the seaweed.

"How did you get here?" asked Merry.

"I didn't walk, because I couldn't. Had to hire a fellow to bring me down, and then he didn't want to get near enough to the island to set me ashore. Wanted me to swim. Charged me five dollars, too. Never mind; the company will have to pay it."

"What company?"

"Why, the company I represent."

"But what company do you represent?"

"The greatest land improvement and development company on earth. You must know the one I mean, for it is the only one. It is the Bay Islands Land Company. The Eastern Bay Land Company has sprouted in competition to us, but we purpose to nip the rival concern in the bud. I am here to investigate such islands as may eventually become summer resorts and obtain options on them when I can get at the real owners. That's one great difficulty—to find the real owners. Some of them do not seem to have any owners, and yet sheep are pastured on them summer and winter. Some of them are owned by the government. Down at Vinal Haven I heard about Devil Island. They said there was some sort of a mystery here. An island with a mystery is certain to be a great attraction for summer visitors. I made a skip for Devil Island to see if it had any attractions beside the mystery. Had hard work getting here. Nobody at Green's Landing seemed to feel like dropping me here, you refused to do so, I couldn't walk. But I didn't get excited. The more difficulties beset my path the cooler I became. I am here, gentlemen, and I'm glad I came. I admire clams. They are fine. I think these clams are the finest I ever tasted. Have some, boys."

Mr. Cooler seemed to regret the time he had spent in talk, for he made a fierce dive at the clams and raked out two of them.

Merriwell's friends all looked at him to see what he would do under the circumstances. Frank was smiling, but there was a look of doubt on his face. For once in his life, he seemed in a quandary. There was something about this little, chuckling, jolly old man that seemed to forbid anyone to do him personal violence. Bruce Browning felt that. He realized that he would feel ashamed of himself if he should give the old fellow a shaking. And it was plain that Cooler could not be frightened away in any ordinary manner. Nothing seemed to alarm him.

"Sit up and eat some clams, fellows," said Frank, quietly. "Let him fill up, and then we'll tie a big bowlder to his neck and sink him out here in the harbor."

"Hum!" coughed the man in gray. "That's right, young man—let me fill my sack with these clams before you put me to soak. Perhaps you had better let me rest a while after that, too, for I never like to take a bath after a full meal. It isn't healthy. The best physicians condemn the practice."

So, with the exception of Hans, they again gathered around the clams and started to enjoy the feast. Hans retired by himself and sat on a flat rock, muttering and looking savage. At times he would shake his fist at the back of the man in gray.

Mr. Cooler seemed to have a remarkable ability to talk and devour clams at the same time. As Browning afterward expressed it, he "talked a blue streak." He told them he was a great traveler, he had been all over the United States, all over the world.

"Why," he said, "in Berlin I appeared at court."

"How much was the fine?" asked Frank, with a twinkle in his eye.

"Young man," exclaimed Cooler, "you astonish me. To look at you, I would not suppose you could be frivolous. I am slightly that way myself. Can't help it; born that way. Always see something humorous in everything. It's better than medicine; it keeps the liver in a healthy condition. Now, clams are hard to digest, but taken in connection with laughter and jollity they digest much better. There is enough sadness in the world if we do not go around with our faces drawn down. Be jolly. That's my motto."

There was something infectious in his light spirits and careless air. Despite themselves the boys found they were growing interested in this queer old fellow.

Frank studied Mr. Cooler carefully. Had he not felt certain that the man was playing a part, he would have enjoyed the old fellow's chatter. But Frank could see beneath the surface, and he was absolutely satisfied that Mr. Cooler was not what he represented himself to be. Frank had never heard of the Bay Islands Land Company; he did not believe there was such a company in existence.

If Cooler was lying, why was he doing so? What was his object in attempting to force himself upon them? Why had he come to the island in such a manner?

Frank had decided that Cooler was a spy and he had been set upon them by the very ones who were so determined to drive them away from that island. In that case, this light-hearted, careless old fellow was connected with a gang of criminals who did not hesitate to do murder in order to conceal their crimes.

Mr. Cooler did not stop eating clams till the last one was devoured, and he disposed of that himself.

"Ah!" he sighed, drawing back and finding a comfortable position, where he could sit with his back resting against a bowlder. "Now, I do feel good! Young gentlemen, I am glad you came. Accept my congratulations on this remarkably successful clambake. You have done a good job; I have done another. My stomach has not been in the best possible condition lately. I've been living at home. My wife cooks. Six months ago she was a magnificent, a celestial cook! Oh, how beautifully she could broil a beefsteak! But, alas! Also alack! She got the bicycle craze; she bought a wheel. Now she is an inveterate scorcher."

He took a pipe out of his pocket and began to fill it, chattering away in a jolly manner as he did so. He seemed inclined to do all the talking.

"Doesn't your jaw get tired at times?" inquired Frank.

"Eh?" came in surprise from the little man. "Why?"

"I should think it would, you talk so much."

"He! he! Ho! ho! Wait a minute. Ha! ha!—knew there was another way to laugh if I could think of it. Jaw get tired? My dear young gentleman, if you had a wife like mine, you would consider it a privilege to talk occasionally. I do not get an opportunity when I am at home. When I get away from home, I make up for lost time. Haw! haw!—came near forgetting that method of laughing. Don't mind me. I know I am something of a chinning machine, but I am harmless. Why, I wouldn't harm a—a—a lion."

He lighted the pipe and puffed away a few moments, talking a streak while he smoked. Frank was considering the advisability of pinning him down and demanding to know his real reason for being there, when, of a sudden, the little fellow jumped up spryly as a boy, exclaiming:

"This won't do. I must complete my tour of investigation. I must attend to business. I must look the entire island over and be ready to leave when that man comes back for me. Young gentlemen, I thank you for your hospitality. I wish I might stop longer, but, unfortunately, I cannot. So long, so ling, so lung."

Browning made a move, as if to stop the man, but Frank gave a sign to let him go. Mr. Cooler scrambled nimbly up the bank, turned and waved his hand with a flirting motion, and then vanished into the bushes.

"Fellows," spoke Frank, quickly, "I'm going to follow him. I must do it alone. I'm armed. I can take care of myself. But if I do not return in an hour, look for me."

Then he sprang up the bank after the mysterious man in gray.