Ralph spoke, as, after enjoying a hearty breakfast of fruit, steaks and coffee, the two latter cooked on the River Swallow’s electric broiler by Percy Simmons, the three boys, who had passed such a sleepless, trying night, yawned openly in each other’s faces.

Malvin had the wheel with orders to steer direct for Dexter Island. Ralph had already questioned the man and, as Harry Ware had prophesied, Malvin, the inscrutable, had his excuses all down “pat.”

It was as he had said, he declared. The swift current at the point from which the lads had left the larger craft in the tender had caused the anchor to drag. Caught by the swift current, and with only the Norwegian to run the engines, Malvin declared he had had a narrow escape from going on the rocks.

His story was circumstantial, direct, and told without the flicker of an eyelid. Ralph had no choice but to accept it, as well as Malvin’s explanation that he had been searching for the boys ever since he had regained control of the large craft.

It is almost unnecessary to say that Ralph, in view of his suspicions of the man, did not believe, at least as a whole, Malvin’s carefully detailed story. In fact, he resolved to question the Norwegian hand at some later time. But it may as well be stated here that from Hansen, a stolid fellow who fully lived up to his title of “squarehead,” the boys were able to glean but little.

Ralph and his chums slept till noon. They were astonished when Harry Ware, the first to awaken, peeped out of a porthole and announced that they were lying at the dock at Dexter Island.

“Confound that fellow Malvin,” muttered Ralph. “I told him to call us as soon as we landed off the island. We must have got here more than two hours ago, and yet he let us sleep; just another instance of his carelessness.”

There came a knock on the cabin door.

“Come in,” cried Ralph, and then, as Malvin entered with a folded paper in his hand, he demanded why they had not been called.

“My father was expecting – ” began Ralph, when Malvin interrupted him.

“Begging your pardon, sir, here is a note from your father.”

“A note?” exclaimed Ralph, in an astonished voice.

“Yes, sir.”

“I don’t just see why dad should send me a note, when he is here on the island himself,” said Ralph, as he took the folded paper.

“That’s just it, sir, if I may say so,” said Malvin, more obsequiously than ever; “you see, he isn’t here.”

“Not here!”

“No, sir. He left the island last night on Mr. Collins’ boat. The servant who handed me the note said that it would explain everything.”

“All right. You can go, Malvin.”

Ralph unfolded the paper and saw that scrawled on it in his father’s big, forceful writing were a few words. It was characteristic of the older Stetson that he didn’t waste words when he had anything to say. The note read as follows:

“Dear Jack: Called away to Montreal. Conference on a steel-rail deal for the new Georgian Bay Railroad. Can’t tell when I’ll be back, but get along as best you can and enjoy yourself.

“Dad.

“P. S. – I hailed Collins’ boat as she went by and he will take me to Point Lalone, where I can catch the Grand Trunk for Montreal. My address will be Imperial Hotel, Montreal.”

“Well, if that isn’t too bad! Just when we need his advice, too,” burst out Harry, as Ralph concluded reading the brief note aloud to his chums.

“It is hard luck. But it’s just like dad,” laughed Ralph. “Here he comes up here for a vacation, and the first thing you know he’s plunging off to Montreal to bury himself in work again!”

“That’s the American business man all over,” commented Percy Simmons judicially; “duty before pleasure; the nose to the grindstone always.”

“No danger of your ever being taken that way,” scoffed Harry Ware; “a hammock and a big glass of ice cream soda for you, if you ever get rich.”

“Oh, I don’t know that I’m any exception to some folks I know,” retorted Percy airily.

“Say, fellows, let’s go up to the house,” suggested Ralph. “I want to make some inquiries about what time dad left, and so on. Then this evening we might take a run over to the Canadian shore and send a wire to the Imperial.”

“All right,” rejoined Harry; “suits me.”

“Look out, we might encounter that spook craft again,” said Percy Simmons teasingly.

“Oh, all right for you,” retorted Harry, flushing up, “you, buried down in the engine room! You didn’t see that boat when she burst out into a green glare. I thought sure it was that Lost Voyageur craft that they tell about.”

“I’ve a notion,” remarked Ralph, as they walked up the path leading from the boat landing to the large, handsome house that topped a rising knoll, “I’ve a notion that others than ourselves might be interested in hearing about that ghost craft.”

“Who, for instance?” asked Harry.

“Why, the authorities. I’ve a strong inclination to report the matter to the Canadian police when we run over there to-night.”

“Why not kill two birds with one stone and run into Cardinal? We could find out there how our young friend is getting along, and also do what you suggest. But what makes you think the authorities would be interested in the matter?”

“Why, just this. That craft is engaged in some sort of nefarious business, probably smuggling. It’s the only plausible explanation for the conduct of those on board her, and all their devices to throw pursuing craft off her track.”

“Smuggling! I guess you’ve hit the nail on the head, all right, Ralph. But why should she have been seen off this island?”

“That is exactly what I want to find out,” was Ralph’s rejoinder. “In fact, if I wasn’t so certain that some link exists between that queer, night-roving boat and Dexter Island, I wouldn’t take so much trouble to run all possible clews down.”

“Hark! What was that?” exclaimed Harry Ware suddenly, stopping and wheeling right about face.

“What?”

“I heard a rustling sound in that clump of bushes,” explained the boy.

“Gracious! More spooks. You’ve got ’em on the brain,” scoffed Percy Simmons loudly.

“Say, just can that comedy stuff of yours, will you?” demanded Harry Ware. Then turning to Ralph, he said, “It wasn’t my imagination, Ralph. I sure heard something in there.”

“Probably a squirrel. There are several on the island,” rejoined Ralph.

“Yes, make a noise like a nut and maybe he’ll come out,” kindly suggested Persimmons.

“Thanks for the suggestion, but I’ll leave that to you. You see, you could do it more naturally,” parried Harry Ware, to Percy’s discomfiture.

“We’ll take a look in there just to satisfy ourselves,” said Ralph, who, for some reason, appeared to take Harry Ware’s report more seriously than did Persimmons.

But a search of the clump revealed no sign of life, human or animal.

“Score up another one to the spooks,” chuckled Persimmons.

But it was no spook or animal, either, that had made the rustling sound which Harry’s sharp ears had detected. It was a man; Malvin, in fact. He had glided like a weasel from the boat the instant the boys left it. Following a circuitous track, veiled from the main path by flowering shrubs and ornamental bushes, he had secreted himself in the clump of plants to which Harry had drawn attention.

He had heard almost every word of the latter part of their conversation, and an evil smile mantled his face as he listened. When the boys stopped short he had glided off like a snake through the screening shrubbery, and as he went he muttered words that boded no good to the boys, should they put into effect their intention of informing the Canadian authorities of the “ghost craft” and its ways.

Clearly Ralph had not guessed wrongly when he hazarded the belief that a link existed between Dexter Island and the mysterious men of the night-roving motor boat.

The link was Roger Malvin.

CHAPTER XV
CROSS PURPOSES

Following out his prearranged plans, Ralph ordered the River Swallow to be made ready for her run to Cardinal that night. After a good supper the three young Border Boys, now changed to motor boatmen, sauntered down toward the dock somewhat ahead of the time they had decided on leaving.

Harry Ware was in advance of his comrades, and as he turned an angle in the patch he came into full view of the River Swallow lying at her dock.

“What a pretty picture she makes lying there,” he thought. “My, to look at her you’d never think she could hustle over the water the way she can!”

Malvin and Hansen were standing near the craft, and the former turned as Harry came round the corner.

Instantly a long, low whistle came from the fellow’s lips, and Harry could have sworn that at the same instant a third figure arose from the deck of the River Swallow, where it had seemingly been lounging, and vanished down the forescuttle.

Harry Ware rubbed his eyes.

“Well, I’ll be jiggered!” he exclaimed. “Am I seeing things, or what? There are Malvin and Hansen on the dock. Besides the servants, they are the only men on the island, and that man on the deck – or the man I thought I saw on the deck – is most assuredly not one of them.”

He stood there puzzled exceedingly by what he had seen, for he was almost certain that his eyes had played him no tricks. Yet if he had really seen a third man on the River Swallow, how had he come there? No boat had come into the dock that afternoon, and there was no other way of landing on the island except at a point which was commanded by the house. It was another mystery to be added to the strange events that appeared to be piling up around the boys in baffling confusion.

“Shall I tell the others about it and risk getting the life joshed out of me?” thought Harry to himself, as his comrades’ steps drew nearer.

After a minute’s cogitation, he decided to remain silent about what he had seen – for that it was no optical delusion he was certain.

“But I couldn’t convince them of that,” he mused. “They’d say I had been seeing spooks again, and Persimmons would kid the life out of me. No, I guess I’ll keep my mouth shut and do some detective work on my own account.”

With this resolution in his mind, he joined his chums, and, arm in arm, the three strolled down to the River Swallow.

“All ready, sir,” declared Malvin, “but you’re a little bit ahead of the time you said, sir. I wasn’t expecting you.”

Harry looked sharply at the man.

“No, I’ll bet you weren’t expecting us,” he thought.

“All right,” responded Ralph to Malvin. “Percy, get below and tune the engines up. It is almost dusk. I would like to get under way before dark.”

Persimmons dived below, donned his engineer’s overalls and began to test up his engines for the night run. To his surprise, they responded sluggishly to his efforts to get them in working order.

“The first time they’ve laid down on me,” he muttered, as, monkey wrench in hand, he tried to locate the source of the trouble.

“What’s the matter?” hailed Ralph impatiently down the tube. “Aren’t you ready yet?”

“Not yet. There is some trouble here I can’t locate.”

“Bother! I wanted to get under way as soon as possible. What do you think is the matter?”

“Impossible to say yet.”

“Well, hurry up and do the best you can.”

“You bet I’ll do that. It may take some time, though.”

“But they were working all right when we tied up this afternoon.”

“That makes it all the more puzzling. Something has happened to them between then and now, that is certain.”

The young engineer went vigorously to work. Systematically he went over wiring and ignition and tested the compression. All were in perfect working order, and yet the engines only responded with a lifeless series of “shoo-oo-o-oofs-s-s!” to all his efforts.

Percy Simmons knitted his brows. He sat down on a leather-covered bench that ran along one side of the engine room.

“Let’s see; I’ve been over everything,” he mused, “gasoline valves, spark plugs, wiring, batteries, magneto and all. They’re all running as smoothly as a hundred-dollar watch. What the dickens – ”

He broke off suddenly.

“I’m a fine engineer!” he exclaimed. “The carburetors!”

Industriously he commenced examining the carburetors, the “hearts of the motors.” There were four in all on the twin four-cylinder engines of the River Swallow. After he had worked a while, Percy Simmons made a discovery that brought him to his feet with a yell.

In the bowls of all the carburetors sand had been placed. This, of course, prevented the proper mixture of air and gasoline taking place, and made it impossible to start the engine.

“Now what wretch can have done such a thing?” exclaimed Percy to himself as he made this discovery. “Somebody with a knowledge of engines and how to cripple them in just the last place any one would think of looking to locate the trouble!”

Malvin’s was the first name that flashed into his mind, for suspicion is one of the most infectious of mental maladies, and Ralph’s attack of “nerves” in regard to the former captain of the River Swallow had communicated itself swiftly and forcibly to his two young chums.

But a moment’s reflection caused Persimmons to reject this explanation of the sanded carburetors. Malvin, while capable of running an engine when it was in perfect working order, had no technical knowledge of machinery such as the person who had maliciously “doped” the carburetors must have possessed.

Hansen? No, the Norwegian was even less skillful about a motor than Malvin. Who, then, could have been responsible for such a wanton act of vandalism?

“Gee! If we get up against any more mysteries I’m going to quit and go back home,” breathed Persimmons agitatedly to himself. “What with spook motor boats, mysterious ghostly lights and strange doings on uninhabited islands, and lastly these sanded carburetors, life along the St. Lawrence is getting too rich for my blood.”

In response to Persimmons’ summons, Ralph came below. The young captain’s shipmate explained the state of the case to him.

“What do you make of it?” he concluded.

Ralph could only assume a puzzled expression.

“I don’t know what to say,” he said.

“Well, Malvin and Hansen are pretty well eliminated, don’t you think?”

“I guess so. I agree with you that neither is possessed of enough technical engineering knowledge to enable him to cripple a motor in this fashion.”

“That settles that, then. But it is equally certain that none of us did it.”

“That goes without saying.”

“Then we come down to one culprit,” announced Percy, looking important.

“Who is that?”

“One of Harry Ware’s ghosts,” declared Persimmons soberly, but with a twinkle in his eye nevertheless.

“I guess we can safely call the ghosts out of it,” laughed Ralph, in spite of his vexation. “The thing is, who would have a motive to try to prevent the River Swallow leaving Dexter Island to-night.”

“There’s only one motive that I can suggest,” said young Simmons seriously.

“And that one is?”

“A desperate desire to prevent us from communicating to the authorities our experiences of last night.”

“But who could know anything about that? We agreed to keep that part of the object of our journey to ourselves. Nobody could know of it.”

“Unless somebody overheard us when we talked it over.”

“What do you mean?”

“That maybe Harry Ware wasn’t so far off as we thought he was, when he declared he heard a rustling in that shrubbery.”

“But, even so; even if anyone did overhear us, Malvin, for instance, we’ve already decided that he couldn’t cripple the engines in such a skillful manner.”

“That being so, there is only one explanation. The sand is there. Some one placed it there. It wasn’t one of us. It is practically impossible that it could have been Malvin or Hansen. That lets everybody out.”

“Yes,” said Ralph slowly, “unless – ”

He paused.

“Well, unless what?”

“Unless there is somebody on board this boat that we know nothing about.”

Percy Simmons broke out in a frantic yell.

“Holy Mackerel! You’re getting ’em, too. We’ll all be seeing things before we get through.”

CHAPTER XVI
HARRY PLAYS DETECTIVE

It is strange upon what slender circumstances big results sometimes depend. Had the fear of ridicule not held back Harry Ware from telling the others about the figure he had seen glide along the deck and vanish in the crew’s quarters of the River Swallow, a great part of the events of that night might have turned out differently.

As it was, however, Harry kept his counsel, with what results we shall see before long. The trouble with the engines once located, it did not take Percy Simmons long to adjust matters, and within half an hour he had the big motors whirring as evenly as if nothing had ever disturbed the even tenor of their workings.

As soon as he was notified that everything was all right below, Ralph rang for the reverse and the River Swallow backed out from her dock into the darkness that was falling fast. But for the delay, thought Ralph, who had chafed impatiently over it, they might have been in Cardinal by that time. But there was no help for it, and as soon as he had room to turn he sent down a clanging signal to Persimmons for “full speed ahead.”

Harry Ware was on the bridge by the young captain, but after a while he said he thought he smelled gas, and went forward. He wanted to explore the crew’s quarters for himself. Malvin and Hansen were on the lookout stations in the bow, and, as Harry approached the forescuttle, the former came up to him.

“Where are you going, sir?” he asked in a tone that struck Harry as being rather agitated.

“Why, we suspect there’s a leak in one of the gas tanks,” was the boy’s ready reply. “I’m going down there to see if I can locate it.”

“I’ll go, sir,” interrupted Malvin eagerly; “let me go, sir.”

“Don’t bother yourself,” replied Harry; “your place is forward on the lookout. Captain Stetson would be angry if he knew you had left it. You’d better go back.”

Malvin did not obey at once. Instead, he placed his head right over the scuttle, and in a loud voice announced, after a minute of sniffing, that he could smell no fumes of gasoline.

“It’s no use your taking the trouble to go nosing around down there,” he said, turning to Harry. “If the gas was leaking, I’d smell it sure.”

“Nevertheless, I shouldn’t be doing my duty if I didn’t obey Ralph Stetson’s orders,” stoutly declared Harry. “Let me pass; I’m going down. I’d recommend you to get back on your station.”

Malvin’s rejoinder was peculiar. He did not, in fact, address it to Harry at all. He placed his mouth over the scuttle and in a loud voice, unnecessarily loud it sounded to Harry, he bawled out:

“Oh, all right, sir. Go below if you want to. But – LOOK OUT BELOW – there’s some low carlins there you might bump your head on.”

The last part of this speech was delivered in low and cautionary tones. Having uttered the warning, Malvin turned and, with a respectful nod, paced back to his post of duty.

“Now I wonder why he hollered, ‘Look out below,’ at the top of his lungs like that?” pondered Harry.

“Well, I’ll give it up,” he murmured, renewing his meditations. “Anyhow, here goes for an exploration of the forecastle.”

He dived below, having first switched on the electric light in the sailors’ quarters by means of a switch at the head of the ladder leading below.

As he descended the steep rungs, not without difficulty, for the River Swallow was being driven fast and was pitching and rolling considerably, he looked sharply about him. But there was nothing to indicate that anyone was in hiding there. In the men’s bunks the beds were neatly made up. In one corner were their chests and personal belongings. Everything was shipshape, orderly and – empty.

“It was my imagination then, after all,” breathed Harry as he looked about him; “I’m glad I didn’t say anything to the fellows.”

At precisely the same moment, Ralph was remarking to Persimmons, the latter having come on deck to gulp down a breath of fresh air:

“Don’t say anything about the sanded carburetors to Harry, Percy. He’s scared enough as it is.”

“You can bet I won’t. He’d be off on his old spook tactics again if I did,” responded the Simmons boy with alacrity.

And thus did the lads on board the River Swallow play at cross purposes, little dreaming what mutual benefit might have resulted from a comparison of notes.

Firmly convinced that he had been the victim of a delusion, Harry made his way back to the deck and retraced his steps aft to join Ralph on the bridge.

“Everything all right?” asked the latter.

“Oh, sure.”

“Malvin at his post?”

“Oh, yes. He and Hansen were right on the job. There with both feet.”

“Good. I didn’t feel altogether sure of that Malvin fellow.”

Without further comments Ralph reverted to his duty of steering the River Swallow through swiftly moving currents and eddies, for they were bound up the river. Harry leaned against the rail beside him.

“Whereabouts are we?” he asked as the boat sped along through the darkness.

“Passing Chimney Island. You can make it out off there to the left.”

“Not up to Windmill Island yet?”

“Not yet. Anyhow, we won’t go near it going up. I’ll pass it on the return trip, though. We can make better time by striking the current there.”

The remainder of the journey to Cardinal, a rather sleepy, though fairly populous, Canadian town, was made without incident. As they came abreast of the town dock, which was brilliantly illuminated with electric arc lights in expectation of the arrival of the steamer bound down the river for Quebec, they noticed the crowd idly gathered there. It was ready for any excitement and broke into a cheer as the fast boat came sweeping up to the dock. Then, at a signal from Ralph, the River Swallow suddenly slackened speed, churning the waters whitely with its reversing propellers, and eventually came to a standstill with the precision of an auto being driven up to the curb.

It was a fine bit of boat-handling that the spectators were quick to recognize and applaud.

Malvin, bow line in hand, leaped ashore as the River Swallow glided up, and Hansen equally quick, for the man was a good sailor, hopped nimbly about, dropping fenders to prevent the racing motor boat’s sheeny sides being scratched or marred by contact with the timbers of the dock.

“Good bit of work that, lad,” said a grizzled old man on the dock, as the boys came ashore, all dressed in natty yachting garments, visored caps, blue coats, white flannel trousers and white canvas shoes.

“Thank you,” laughed Ralph. “I guess my engineer was as much responsible for it as I.”

“Ah-hum,” said the old man. “I used to handle a boat once, but now I ain’t fit for nothing but just night watchman at the grain elevator yonder,” and he pointed to a towering structure that loomed against the dark sky.

Malvin and Hansen had been left in charge of the River Swallow. Arm in arm the three boys started up the street. But after they had gone a short way, Harry suddenly declared that he had left something he wanted in the cabin.

“I’ll go back for it. You fellows keep right on,” he said.

“Where shall we meet you? We’re bound for the hospital,” said Ralph.

“Where from there?”

“To the Western Union offices.”

“And then?”

“Why, I guess to the police station or whatever answers to it over on this side. I’ve a burning desire to lay the facts in the case before the authorities.”

“Very well then, I’ll meet you at the telegraph office.”

And so it was arranged. While Percy and Ralph hastened to the hospital, which lay at one end of the town, Harry made the best of his way back toward the River Swallow. His conscience hurt him a bit for not having told his friends the true reason for his return to the motor craft.

Harry was not in search of something forgotten.

He was on the trail of the third man who, despite all evidence to the contrary, he was still firmly convinced was concealed somewhere on board the River Swallow.