“Wonder if this can be the same parties we met yesterday?” George remarked, as they watched the approach of the bustling little motor boat, which pushed over the water with a series of fierce explosions, not unlike the discharge of a pack of giant fire-crackers.

“No, I don’t think it is,” Herb spoke up, in answer. “Fellow at the wheel looks like a Canuck guide from one of the hotels, a full-blooded Indian, and the man with the glasses and the fishing rod is more like a college professor, I’d say.”

“That was just what I thought,” put in Jack.

“Anyway, we’ll soon know, for they’re coming in, as sure as anything,” Josh added.

Inside of five minutes the noisy little boat swung close to where the boys sat watching. The gentleman sitting holding the rod, and winding up his reel with a clicking sound, waved a hand in cheery greeting.

“How d’ye do, boys?” he said, cordially; and somehow Jack rather liked the tone of his voice, as he also did his looks.

“Any luck, sir?” he inquired, as is the custom at such a time.

“Had two fierce strikes; but I’m afraid I’ve lost my cunning, for I let the beggars have a slack line, and lost both. Are you fishing any? I saw two lads in little dinkies like that one yonder, fishing over by the long island, and guessed that possibly they belonged to your party.”

“Yes, they do,” George replied; and went on to tell about what luck they had had, with the usual pride of a successful fisherman.

Jack meanwhile was not saying much, but observing the gentleman. It struck him that the other was trying to make himself very agreeable; and somehow he could not help remembering the fable that Herb had spoken about so recently. Having failed to scare the motor boat boys off by stern means, were milder tactics about to be adopted now?

Presently the other thought he ought to introduce himself.

“I am Professor Herman Marshland, of Ann Arbor,” he said, modestly.

So Herb started to tell just who they were, and how they happened to be knocking around on the St. Lawrence at this time.

“Have you been stopping long in this cove?” asked the other, in what he doubtless intended to have appear as a casual way; but Jack saw that he seemed to set more store by the question than surface indications would indicate.

“Why, sure, we have, Professor,” George said. “We might have gone on before now, but we just hate to leave under fire, you see.”

“Excuse me, but I hardly grasp your meaning, I fear,” remarked the gentleman, with one of his winning smiles.

“Well, you see, some persons appear to have taken offense because we’ve monopolized their dandy cove here. And they’ve been trying in all sorts of ways to shoo us away. Last night they threatened to run us down with a speed launch that came buzzing around that point of the island there. And then, would you believe it, sir, they even went so far as to attempt to scare up-to-date American boys, by setting up a silly ghost game on us.”

“What’s that you say?” remarked the gentleman, interrupting George. “A ghost? Now, that’s right in my line, you see. I’ve been making a study of all manner of strange and incomprehensible manifestations along that line for five years. In that time I’ve investigated dozens of so-called haunted houses. Why, you arouse my interest at once to fever heat, my young friends.”

“And did you ever discover a real, genuine bona fide ghost, sir?” asked Josh.

Professor Marshland smiled.

“I never have,” he replied, with a forlorn shake of the head; “but I still live in hopes. What knows but what this may be the golden opportunity I have waited for so long? You must tell me all about it, boys. And afterwards I’ll just drop off and take a little look around, on my own responsibility.”

Of course George and Herb were only too willing. Assisted by an occasional word from Josh, they soon told the story. Then Josh in turn related what he and Jack had found out when they investigated ashore. The college professor seemed deeply interested in the forlorn cabin, the dilapidated door of which was fastened by a broken padlock.

“They say ghosts are peculiar in many things,” he remarked at the conclusion of the little talk. “And that might account for the padlock. It’s all very interesting, boys. I only regret that I was not here when the manifestation occurred. Perhaps, if I hung around tonight, the thing might get up courage enough to show again. It would repay me for all my trip here. I came for the fishing; but to catch a ghost in the act, would be positively refreshing, I assure you.”

Jack was still watching the professor. While he liked the other, somehow he seemed to feel that there was something rather strange about him. He seemed to be studying the four lads as though seeking to read them, and make up his mind as to whether they were just what they claimed.

Could it possibly be that he was connected with those mysterious men who seemed so bent on chasing the motor boat boys away from the lonely island?

After chatting for some time, and making quite a favorable impression on Herb, George and Josh, the professor remarked that if they would excuse him he would step ashore, and take a look at the delightful old ghost cabin.

Josh was just about to volunteer to accompany him, when he caught the quick look Jack cast in his direction, accompanied by a negative shake of the head.

“If he wanted us he’d have said so, Josh,” came in a whisper.

A minute later the gentleman, having managed to land, vanished amid the heavy growth of timber and brush.

Josh looked at Jack.

“Sure as you live, he’s following that trail, Jack,” he said.

“That’s only natural,” remarked the other, “because, you see, it was mighty plain, as though lots of people had gone back and forth.”

“Yes,” observed Josh, simply, “if them chaps were camping in the cabin, and going out fishing every day, of course they’d make a well-worn trail down to this cove here, where their boats must have been tied up. I’ve been thinking, Jack, that p’raps they’re engaged in some sort of fishing that’s illegal, such as setting nets against the law. Say, wouldn’t that be an idea now? And if true, it must explain just why they watched us so close. They thought we might be wardens getting on the track of their business. How’s that for a guess, fellows?”

“Sounds kind of fishy,” remarked George.

“Scaly, I should say,” Herb spoke up.

But Jack said nothing. He was thinking along the same line Josh had suggested, but in an altogether different way from the lanky cook of the Wireless.

To tell the truth, Jack would have been pleased could he have slipped ashore to observe what the professor from Ann Arbor could be doing just then; but he did not dare venture. It would look too much like impudence. As he himself had said, if the gentleman had wished for their company, he certainly must have asked them to go ashore with him.

As to his being deeply interested in ghosts, and a patient investigator of remarkable manifestations for years, Jack took all that with a grain of salt. Perhaps it might be so, but Jack believed he was not far wrong in believing that Professor Marshland had only mentioned the fact to excuse his evident desire to go ashore and look around.

He was gone a long while. Indeed, Jack guessed that perhaps the gentleman could have explored the whole island in the time that elapsed before he again showed up. Still, there was also a chance that he might have been doing something in connection with the old cabin.

When he did appear he was smiling broadly.

“Sorry to say I couldn’t find any evidence of the supernatural,” he remarked, in answer to the eager look Josh gave him as he clambered aboard his stubby little boat once more. “And that inclines me to the belief that some one who loves a practical joke was only trying to throw you into a state of fright, boys. I regret, too, that I cannot remain over a night with you, in the hope of being granted a look at this wonderful spectre. If anything more remarkable occurs, I’d be very much obliged if one of you would write an account of it and mail me at the college.”

“Sure, we will, Professor,” said the willing Josh. “And if so be we capture that flickering ghost, we’ll send it to you by express, charges collect.”

“Do so,” laughed the gentleman. “I won’t object, I assure you. Well, here’s wishing you luck, boys. And thank you for all the information you’ve given. It may be of more assistance to me in my calling than you imagine. Start up, John. It’s back to the hotel for us now.”

So the noisy little motor went chugging away, passing around the point; and by degrees the sound died out, as other islands came between.

“Say, let me tell you, I like that man,” Josh up and said, without any urging.

“He is a smart one, all right, and don’t you forget it,” remarked George.

“Was he really trolling, do you suppose, in that horrible, noisy power boat?” asked Herb, skeptically.

Jack himself had a suspicion that the rod and line were only being used for a mask of some sort. Everywhere he looked, the mystery seemed to be getting deeper. First the strange actions of the men in the rowboats; then the appearance of that foolish ghost on the island; the questioning of the fisherman whom George and Herb had met while away on the preceding day; the peculiar things he himself had discovered ashore; and now, last but not least, the coming of this pretended fisherman, who asked skillful questions, and made out to be a genuine ghost hunter—taking all these things together, and it can be seen that Jack had about all he wanted to ponder over for the rest of that day.