"Give me something easy," replied Nick. "Jack always is a puzzle for me.

He has such bright thoughts I don't just seem able to grapple with 'em.

But depend on it, he's thinking of something right now."

"I guess he's worrying about those men," suggested Josh.

"Oh! I don't think so," George hastened to say. "They wouldn't dare try attack us here, you know. It would be a breach of the law for which they could be sent to prison for years. Jack's got some other notion in his brain, believe me."

Meanwhile the object of all this speculation idly paddled a little distance out on the moonlit water, and sat there in his small craft, as though enjoying the silvery glow.

He looked around him on all sides, and particularly in that quarter of the wind from whence had come the faint "chug-chug" of a motor's eccentric pulsations. But nothing could be seen save the dim outlines of the next island.

After a while, as a cloud covered the moon, Jack came back and clambered aboard once more.

"Here, is this an all-night session of the club?" he asked. "Already it's ten minutes after eleven. If you fellows want to get any sleep tonight, better be turning in right now. Josh and myself have the first two hour watch, you understand."

Accordingly there was a breaking up of the conference; goodnights were exchanged, and those who had drawn the first spell of rest crept into their comfortable blankets.

Of late their sleep had been somewhat broken, as we happen to know, what with the coming of specters and such things. On this account every one of the four soon dropped off asleep.

Jack could hear Jimmie breathing heavily in less than ten minutes.

Apparently Jack had something on his mind, for leaning over toward where he could see Josh sitting he asked in a low tone:

"How is it there, Josh; is Herb asleep yet?"

"I guess he must be," came the answer; "because he's snoring to beat the band, even if he don't make much noise."

"That's where you made a mistake, for it's Nick doing that. Listen again, and you'll see I'm right. And George was yawning when he turned in, so I reckon he's gone over the border, too."

"What do you want to know for?" asked Josh, aware that Jack must have some reason for asking such a question.

"I'll tell you, Josh. I mean to go ash.o.r.e soon," replied the skipper of the _Tramp_.

"Thunder! do you really mean it, Jack?" queried Josh, taken aback; for it would have to be something tremendous that could tempt him to set a foot on that same island in the night time.

"Listen, Josh," Jack went on.

"I am, with all my ears, so go right on," the other sent back over the few feet of water separating the two boats they occupied.

"I didn't say anything about it to the rest, Josh, but I think I saw a gleam of that lantern ash.o.r.e a while back. And I'd like to investigate a little."

"Oh, my! you wouldn't catch me trying it," declared Josh, with an intake of breath that told of suppressed excitement. "But will you take your gun along?"

"Perhaps I'd better, though I don't really expect to use it," Jack replied. "Because, you see, ghosts can't be reached with common lead pellets. But I want you to help me Josh."

"Me? Oh! please don't ask me to go along, Jack. That lame foot of mine has been hurting again like anything, and I'm that clumsy I might tumble all over myself and give the thing away."

"Oh, shucks! I don't mean that," Jack replied. "But when that big cloud sails over the moon I want to slip into my little d.i.n.ky here, and paddle quietly ash.o.r.e. I'll hand you the rope I've got tied to the stern; and when you feel that shake three times, pull the boat out again, and let it float with yours. Understand?"

"Yes, yes. And I'll do it all right, never fear. If it wasn't for that plagued lame foot, now, Jack."

"Let up on that, please. Now, look out, there she goes under."

Even as Jack spoke the moon said goodbye to the world for a short time, and hid her smiling face behind a cloud that was darker than any that had thus far sailed across the starry heavens on this particular night.

Being all ready, Jack crept into the small tender, gun in hand. He pushed alongside the Wireless and managed to pa.s.s the end of a rope to Josh, who was waiting to receive the same.

Gently the paddle was wielded, and the little "punkin-seed of a boat,"

as the boys sometimes termed the d.i.n.kies, was noiselessly wafted sh.o.r.eward. Landing, Jack shifted his person to the sand, and then gave the requisite number of tugs at the rope, after which he shoved the boat off.

He knew that Josh would attend to all that part of the business, and gave it no further heed. Indeed, he had all he wanted to take care of in following out the rather venturesome plan of campaign he had arranged.

For somehow Jack was of the opinion that the mystery of the island was to be revealed to any one daring enough to go ash.o.r.e and investigate, which was just what he had determined to do.

CHAPTER XVII-THE SECRET OUT

Out came the moon again, sailing into a clear field.

But Jack no longer stood there on the little beach. He had taken time by the forelock, and slipped among the rank growth; so that although Josh strained his eyes to the utmost, not the faintest sign of his comrade did he discover.

Jack's idea, of course, was to reach the vicinity of that tumbledown shack. In his mind, that must be the central point of interest in the game. He fully believed, though he had not mentioned the fact to the rest, that the attempt to frighten the boys off with such a ridiculous show of a pretended spirit waving them away, was meant to cover this cabin.

What did it all mean? Why should any man, or set of men, wish to keep others from prowling around that rickety building? Surely, any one with common sense would hardly think to occupy it for a night's refuge. The open air would be far more preferable in every way.

Still, Jack was positive that there was something in connection with this same cabin that moved the unknown parties to endeavor to influence an early departure on the part of the motor boys.

And he wanted to know what that mystery might be.

That was why he had come ash.o.r.e so silently. It also accounted for his creeping along through the bushes as carefully as he knew how, avoiding the trail which he and Josh had followed on that other occasion.

It took him considerable time to draw near the vicinity of the cabin, because he wanted to go without making any noise; and he was not positive but that hostile eyes and ears might not be on the alert.

Twice some sudden little sound close by had sent a thrill of alarm through his heart. But nothing followed, and he realized that these noises must have been made by some little animal, disturbed in his retreat by the creeping past of the intruder.

Jack had made a discovery before he was more than half way between the beach of the cove and the cabin. There was a light inside the old building! He could see little glimpses of it through what must be holes in the walls, where the c.h.i.n.ks between the logs were open, the mud having fallen away in the process of decay.

And as Jack said to himself with a chuckle, ghosts did not, as far as he knew, need lanterns in their business.

Finally the boy found himself close to the side of the cabin. With his heart beating like a trip-hammer, he crept to the first little gap in the wall, and glued his eyes to the aperture.

What he saw was nothing so very astonishing. A man stood inside the cabin, holding a lantern. He was not doing anything, and seemed to be waiting for some other person.

"One of the fellows in that boat today," was what Jack immediately said to himself, as he fastened his eyes on the bearded face.

Even inexperienced as he was, Jack fancied that there was something of a desperate type about the man's countenance. He did not seem to be such a man as one was apt to trust on sight-like that jolly professor from Ann Arbor, for instance.