Whenever he came into this end of the valley Thor always paid a visit to the beaver colony, and occasionally he helped himself to a fat young beaver for supper or breakfast.  This evening he was not hungry, and he was in a hurry.  In spite of these two facts he stood for some minutes in the shadows near the pond.

The beavers had already begun their night’s work.  Muskwa soon understood the significance of the shimmering streaks that ran swiftly over the surface of the water.  At the end of each streak was always a dark, flat head, and now he saw that most of these streaks began at the farther edge of the pond and made directly for a long, low barrier that shut in the water a hundred yards to the east.

This particular barrier was strange to Thor, and with his maturer knowledge of beaver ways he knew that his engineering friends—­whom he ate only occasionally—­were broadening their domain by building a new dam.  As they watched, two fat workmen shoved a four-foot length of log into the pond with a big splash, and one of them began piloting it toward the scene of building operations, while his companion returned to other work.  A little later there was a crash in the timber on the opposite side of the pond, where another workman had succeeded in felling a tree.  Then Thor made his way toward the dam.

Almost instantly there was a terrific crack out in the middle of the pond, followed by a tremendous splash.  An old beaver had seen Thor and with the flat side of his broad tail had given the surface of the water a warning slap that cut the still air like a rifle-shot.  All at once there were splashings and divings in every direction, and a moment later the pond was ruffled and heaving as a score of interrupted workers dove excitedly under the surface to the safety of their brush-ribbed and mud-plastered strongholds, and Muskwa was so absorbed in the general excitement that he almost forgot to follow Thor.

He overtook the grizzly at the dam.  For a few moments Thor inspected the new work, and then tested it with his weight.  It was solid, and over this bridge ready built for them they crossed to the higher ground on the opposite side.  A few hundred yards farther on Thor struck a fairly well-beaten caribou trail which in the course of half an hour led them around the end of the lake to the outlet stream flowing north.

Every minute Muskwa was hoping that Thor would stop.  His afternoon’s nap had not taken the lameness out of his legs nor the soreness from the tender pads of his feet.  He had had enough, and more than enough, of travel, and could he have regulated the world according to his own wishes he would not have walked another mile for a whole month.  Mere walking would not have been so bad, but to keep up with Thor’s ambling gait he was compelled to trot, like a stubby four-year-old child hanging desperately to the thumb of a big and fast-walking man.  Muskwa had not even a thumb to hang to.  The bottoms of his feet were like boils; his tender nose was raw from contact with brush and the knife-edged marsh grass, and his little back felt all caved in.  Still he hung on desperately, until the creek-bottom was again sand and gravel, and travelling was easier.