“Indians!” murmured Barney.

Instantly his mind mirrored to him pictures he had seen in histories of painted savages burning a settler’s cabin.  His blood ran cold.  Here they were, three men in the frozen wilderness, with little gasoline for their machine, with scant provisions and ammunition, and rushing toward perils they could not even guess.  To kill and to escape would both be easy for these desperadoes.

“Go along down the lake and back again.  Use as little gas as possible, but keep in the air.  We better not land at present.”  The very steadiness of the Major’s tone told Barney that this experienced man of the North expected the worst.

As they rushed down the white expanse, many thoughts raced through Barney’s mind.  It seemed that hunger and cold grew upon him with every whirl of the engine-shaft.  He thought of Bruce and La Vaune.  Would they ever return to La Vaune with the money which was rightfully hers?  And Timmie?  Would they ever be able to help him blot the stain from his name?  Barney’s friend, Dave Tower, who had gone North in a submarine on a mission as mysterious as their own; would they ever meet?

They had now turned and were making their way slowly back.  The fire had burned down to a dull red glow.  The forest about had escaped the flames, and this was fortunate.  Should the Indians leave them unmolested, they might possibly find a means of sustaining life by hunting and trapping.

“When we get to the bay, might as well land,” grumbled the Major.  “It’s mighty tough up here!”

Barney assured him that it certainly was tough.  He was glad they were to land, being very sure that if an Indian did shoot him he would not feel it, so thoroughly benumbed was he with cold.

Then, suddenly, he gave a cry of surprise.  They were nearing a point where Conjurer’s Bay should appear.  Instead of the bay he saw what appeared to be merely a broad shoulder of frozen water, and beyond that, perhaps two miles, was a small lake lined by the forest.  It was on the edge of this small lake that the fire smouldered.  The boy rubbed his eyes, then looked again.  Had the cold benumbed his senses?  Was he seeing things?  Was he asleep and dreaming?

Apparently not, for from Bruce through the receiver came a groan, then;

“What’s happened?  The whole shape of the lake has changed within an hour!”

Barney shut off the engines.  In the welcome silence which followed, as they drifted downward in a slow spiral, not a man spoke.  Their eyes were focused upon the earth.

But now there came to their ears a sound like the distant rush of many waters.  This grew rapidly louder, and finally divided itself into rattling and snapping sounds.

Presently the Major let out a roar of laughter.

“Caribou!” he exploded.  “They pass south from the barren lands in herds of hundreds of thousands, so thick they look like land!  Tip her nose up for another circle.  See!  There is the end of the herd away there in the distance.  We’ll be able to land where they have passed in fifteen minutes, an ideal landing-place—­tramped hard.”