Four Boy Scouts, of the Beaver Patrol, Chicago, were in camp on Moose river. They were all athletic young fellows, not far from seventeen years of age, and were dressed in the khaki uniform adopted by the Boy Scouts of America.

If you take a map of the British Northwest Territories and look up Moose river, you will discover that it runs through nearly three hundred miles of wilderness, from Lake Missinale to Moose Bay. The reader will well understand, then, how far “Sandy” Green, Will Smith, George Benton and Tommy Gregory had traveled from civilization.

The camp of the Boy Scouts was situated some fifty miles up the river from Moose Factory, a trading point famous in old Indian days for its adventurous spirits and its profits to the factors. Those who have read the preceding books of this series will doubtless remember the four Boy Scouts named above. Together they had visited the Pictured Rocks of Old Superior, the Everglades of Florida, and the great Continental Divide.

During all their journeys the boys had shown courage and resourcefulness beyond their years, and because of these qualities they had been chosen, by Mr. Horton, a noted criminal lawyer of Chicago, to undertake a difficult and dangerous mission to the Hudson Bay country.

They had traveled by way of the Canadian Pacific to Missanabie, from which point they had proceeded to Lake Missinale. Here they had purchased a “Mackinaw,” a great flat-bottomed craft, in which to transport their tents and supplies down Moose river to the bay of the same name.

They had made most of the journey in native canoes, which they had learned to handle with considerable skill, but now and then they had taken refuge on the big boat, “just to stretch their limbs,” as they expressed it. They left Chicago late in September and it was now almost the last of October.

Those who live in the Hudson Bay country declare that they have three seasons in four months, Spring comes in June, summer in July and August, and autumn in September. At the southern extremity of James Bay, October may scarcely be called a winter month, although during the latter part of the month ice and snow are not infrequent.

The sun was setting on the lads’ first day in camp as the boys rested from their labor of dragging in great quantities of both dry and green wood. Their tents were of double canvas, specially prepared for cold weather, and their bedding and suits had constituted an important part of their baggage.

Almost the entire fronts of the tents were composed of fine, strong silk mesh-cloth. The faces of the boys were well anointed with grease, and masks of mesh-cloth hung about the tents ready for use.

Mosquitos and an insect known as the “bull-dog” had driven many a trapper and hunter out of the swampy regions around Hudson Bay. During the summer it is almost impossible to live in the swamps of that country at all. By protecting their tents and faces, and keeping great “smudges” going, the boys hoped to be able to live in comparative comfort during their stay in that section.

“Look here, Will,” Tommy said, as he laid down a great armful of dry wood, “some one ought to invent some kind of a contraption to kill these flying pests off by the billion. Here it is almost cold enough to snow, and we’re being eaten alive by mosquitos.”

“I reckon it wouldn’t do much good to invent a way of killing the brutes,” Will suggested, “as long as the swamps and pools of the Northwest Territories are turning them out at the rate of a billion a minute.”

“I read a story about how to get rid of mosquitos the other day,” Sandy said. “It might be a good idea to try it.”

“You can always read how to do things, in the newspapers,” Tommy argued. “The only trouble is that the ideas don’t work.”

“This one will work,” declared Sandy. “The way to kill mosquitos,” he continued, “is to throw a great long rope up in the air. You let it stay up in the air; that is, one end of it, and grease it carefully with cold cream and tie a piece of raw beefsteak at the upper end. That will attract the mosquitos. Then when you get several millions up the rope, you cut it in two about twenty feet from the ground and pull the lower end down.”

“It’ll be the foolish house for yours!” Tommy laughed. “How are you going to throw one end of a rope up in the air and make it stay there?”

“I didn’t say how to make it stay up in the air,” grinned Sandy. “I just said you had to make it stay up in the air. Then when the mosquitos get tired of staying up in the ambient atmosphere, they’ll come crawling down the rope and fall off where you cut it.”

“I guess your dome needs repacking all right!” laughed Tommy.

“And then, when they come to the place where the rope has been cut off, they’ll take a tumble for themselves, and you stand under the line and beat their heads off with an axe.”

“Poor child!” laughed Tommy.

“If you leave it to me,” George declared with a grin, “that story about how to kill mosquitos came out of Noah’s ark on crutches.”

The sun was setting over the great wilderness to the west, and the boys hastened to pile more wood on the fire. The forest was alive with the cries of birds, and the undergrowth showed curious eyes peering out at the intruders.

“This beats little old Chicago,” cried George, bringing out a great skillet of ham. “When we live in the city, we’ve got to eat in the house and smell dishwater. When you live out doors, you’ve got a dining room about a thousand miles square.”

“And when you live in Chicago,” Tommy continued, “you can’t get fresh fish right out of the brooks. When you want a fish here, all you’ve got to do is to run out to the river, grab one in your arms, and bring him in!”

“Then run out and get one now!” advised Will.

“Perhaps you think I can’t!” shouted Tommy.

Seizing a head-net the boy dashed away to the margin of Moose river. His chums saw him walking about in quest of a minnow for a moment and then heard the swish of a line. In ten minutes he was back at the camp with a whitefish weighing at least five pounds.

There is incessant fishing in the wilderness north of Lake Superior throughout every month of the year. All through the long winter the ice is cut away in order that the fish may be reached, and there is every sort of fishing between that which engages the labors of sailing vessels and men, down through all the methods of fish-taking, by nets, by spearing, still-fishing and fly-fishing.

Though the region has been famous, and therefore much visited, for many years, the field is so extensive, so well stocked, and so difficult of access, that even today almost the very largest known specimens of each class of fish are to be had there.

“These are the kind of fish the Indians live on during the winter,” Tommy explained as he scraped the scales from his prize. “Only,” he continued, “the Indians don’t clean them at all. They simply make a hole in the tail end of each fish and string them up like beads on sticks which they set up in racks.”

“I never did like cold-storage fish,” Sandy declared, in a tone of disgust. “They taste like dry corn meal!”

While the fish cooked and the boys sat in the protecting smudge of the campfire, the sound of paddles was heard up the river. The swish and splash came on steadily for a moment and then suddenly ceased.

“I thought we were going to have company,” suggested Will.

The boys listened for a time but no further sounds were heard.

“Now what would any one be doing in this wilderness?” Sandy asked. “What would any one be sneaking around us for?”

“Perhaps they don’t even know we’re here!” argued George.

“With that great campfire going?” scoffed Tommy. “Why, they can see the light of that fire for ten miles or more!”

“That’s right,” replied George. “I guess that fire wouldn’t help to hide our presence here any.”

“Suppose I go and see what’s doing?” asked Tommy.

“You know your failings, young man!” Will cut in. “If you go out in the wilderness to see who’s running that canoe, you’re likely to get lost, or come back here after a couple of days with a broken leg or a busted coco! You’d better stay in camp.”

“But I want to know who’s sneaking around our tents!” insisted Tommy. “You come along with me, Will, if you think I’m not competent to go alone,” the boy added with a grin.

Will hesitated for a moment and then providing himself with an automatic revolver and an electric searchlight, the two boys left the camp and soon disappeared in the darkness. They had been gone scarcely five minutes when a shot came from the thicket.