for a time and then passed it to Clay.

“There he goes,” he said, “away up the river, heading for St. Luce! That’s the boy who disconnected the electricity and cut the cable. That’s the boy who we will even up with when we catch him, too.”

“And you’re the boy who’ll wash dishes for a week for talking slang!” Jule taunted.

“I’d wash dishes for a month if I could get hold of that rat,” answered Alex, angrily. “He came near wrecking the Rambler!”

“Well,” Clay said, “we may as well be getting the motors into shape. We can’t stay on this island long.”

“If we do, there’s no knowing what will happen,” Jule suggested. “We’ve had two letters and a runaway to-night and the next thing is likely to be a stick of dynamite.”

“Say, suppose we repair the electric apparatus and get away from this vicinity right now,” suggested Case, “I don’t like the looks of things.”

“Now, look here,” Alex cut in, “I’m ready to get out of this section, but do you mind what the first letter said about going north? Now that means something. If the first letter hadn’t told us to go north, and the men who threw the second letter hadn’t believed that we were obeying instructions, we wouldn’t have been interfered with. Now, there’s a friendly force here, and a hostile force. The friendly people may be mistaken in our identity, but that doesn’t alter the fact that the hostile element is out to do us a mischief.

“I’d like to find out what it is the friendly force expects us to do. If we can learn that, we’ll know why the hostile force is opposing us. And so, it looks to me that instead of running away, we would better find out what is wanted of us. How does that strike you, fellows? Isn’t that deduction worthy of Sherlock Holmes?”

“All right,” Clay declared, “I’m willing to investigate, but we mustn’t spend all our time looking into one mystery, for if we have the same luck we had on other trips, we are likely to come across several more before we go back to Chicago.”

“I’d like to know,” Case said, as they brought up an extra anchor and a new cable, “why we were dumped on this island.”

“To get us out of the way, probably,” Jule commented. “They undoubtedly expected to steal or wreck the Rambler.”

“But the Rambler,” Alex laughed, “has the luck of the Irish, so she’s still able to travel.”

The island upon which the boat had been cast, lay only a short distance from the south shore of the river. In fact, at low water, when the tide was out, it might have been possible to pass to the mainland on dry ground.

Its location was not more than two miles below the little landing at St. Luce. In fact, as the boys afterwards decided, it must have been from this island that the signal flame had burned early in the evening.

Working busily on the repairs, the boys did not notice the arrival upon the island of two roughly dressed fellows, who landed from a small boat and who took great pains to keep rocky elevations between themselves and the cove where the boat lay.

“I wonder,” Jule asked, sitting down on the prow after a struggle with the new cable, “whether the stories I have read about wreckers along the St. Lawrence are true.”

While the boys discussed the possibility of wreckers working along the stream, one of the two men clambered to an elevation which was in turn hidden from the cove by a higher one and waved a red and blue handkerchief toward the shore.

The tide was now running out, and the channel between the island and the mainland swirled like a mill-race. This, however, did not prevent the launching of a boat from the shore, the same being manned by four men. They edged along the shore and then, passing boldly into the current, landed on the island at a point east of the cove. There they secreted their boat and moved on toward the place where the boys, all unconscious of their presence, were repairing the damages wrought by their treacherous guest.

It was Captain Joe who gave the first intimation of the presence of others on the island. He sprang from the boat, paddled through the shallow water between the hull and the shore, and set out for the elevation where the man who had signaled had been standing.

The boys heard a cry of pain, a shout of anger and a pistol shot, and then Captain Joe came running back to where the Rambler lay.

“What was it you said about wreckers?” Case asked with a startled look. “No beast or bird fired that shot!”

“I was only wondering,” Jule answered, “whether there are really wreckers at work along the river. That’s the answer!”

“Well,” Clay said, “we’ll get on the boat to talk it over! In the meantime, we’ll be putting space between the Rambler and this island. If ever a wrecker’s beacon told where to lure a boat to be plundered, that flame we saw on the island told our sneaking guest when to cut the Rambler loose!”

The boys hastened on board and Clay ran to the motors. At that instant, four men made their appearance on the ledge above the cove, beckoning with their hands and calling out to the boys that they had something of importance to say to them.

“They look to me like triple-plated thieves,” Alex commented, “and I wouldn’t be caught on an island with them for a farm.”

Captain Joe seemed to approve of this decision, for he stood with his feet braced, growling furiously at the beckoning men.

“Boat ahoy!” one of the men cried. “We have a message for you.”

“All right,” Case answered, “you may send it by wireless.”

“But it is important!” came from the man.

During this brief conversation, the motors were slowly drawing the Rambler out of the sandy cove, the electric connection having been made, and the men were rapidly approaching the shore. The boat moved slowly, for the keel was dragging slightly in the sand, and the wreckers, if such they were, stood at the water’s edge before the craft was more than a dozen yards away.

Directly, all appearance of friendship ceased, and the men stood threatening the boys with automatic guns.

“Run back!” one of the men cried, “or we’ll pick you off like pigeons!”

The boys had already taken their automatic revolvers from the cabin, and now, instead of obeying the command of the outlaws, they dropped down behind the gunwale and sent forth a volley not intended to injure, but only to frighten.

Apparently undismayed by the shots, the outlaws passed boldly down the shore line seeking to keep pace with the motor boat as she drew out of the cove. Every moment the motors were gaining speed. In another minute, the Rambler would be entirely beyond the reach of the outlaws.

Apparently hopeless of coercing the boys into a return, the outlaws now began shooting. Bullets pinged against the gunwale and imbedded themselves in the walls of the cabin but did no damage.

A tinge of color was now showing in the east. Birds were astir in the moving currents of the air, and lights flashed dimly forth from the distant houses of St. Luce. Against the ruddy glow of the sky, a river steamer lifted its column of smoke. Observing the approach of the vessel, the outlaws redoubled their efforts to frighten the boys into instant submission.

However, the Rambler was gaining speed, and the incident would have been closed in a moment if the connection made between the batteries and the motors had not become disarranged. In the haste of making the repairs, the work had not been properly done.

The propeller ceased its revolutions and the boat dropped back toward the cove. Evidently guessing what had taken place on board, the outlaws gathered at the point where it seemed certain that she would become beached.

Understanding what would take place if the motor boat dropped back, the boys fired volley after volley in order