They had nearly accomplished this work when one morning Kazan and Gray Wolf returned to the swamp.

CHAPTER XX

A FEUD IN THE WILDERNESS

A soft wind blowing from the south and east brought the scent of the invaders to Gray Wolf’s nose when they were still half a mile away.  She gave the warning to Kazan and he, too, found the strange scent in the air.  It grew stronger as they advanced.  When two hundred yards from the windfall they heard the sudden crash of a falling tree, and stopped.  For a full minute they stood tense and listening.  Then the silence was broken by a squeaking cry, followed by a splash.  Gray Wolf’s alert ears fell back and she turned her blind face understandingly toward Kazan.  They trotted ahead slowly, approaching the windfall from behind.  Not until they had reached the top of the knoll on which it was situated did Kazan begin to see the wonderful change that had taken place during their absence.  Astounded, they stood while he stared.  There was no longer a little creek below them.  Where it had been was a pond that reached almost to the foot of the knoll.  It was fully a hundred feet in width and the backwater had flooded the trees and bush for five or six times that distance toward the burn.  They had come up quietly and Broken Tooth’s dull-scented workers were unaware of their presence.  Not fifty feet away Broken Tooth himself was gnawing at the butt of a tree.  An equal distance to the right of him four or five of the baby beavers were at play building a miniature dam of mud and tiny twigs.  On the opposite side of the pond was a steep bank six or seven feet high, and here a few of the older children—­two years old, but still not workmen—­were having great fun climbing the bank and using it as a toboggan-slide.  It was their splashing that Kazan and Gray Wolf had heard.  In a dozen different places the older beavers were at work.

A few weeks before Kazan had looked upon a similar scene when he had returned into the north from Broken Tooth’s old home.  It had not interested him then.  But a quick and thrilling change swept through him now.  The beavers had ceased to be mere water animals, uneatable and with an odor that displeased him.  They were invaders—­and enemies.  His fangs bared silently.  His crest stiffened like the hair of a brush, and the muscles of his forelegs and shoulders stood out like whipcords.  Not a sound came from him as he rushed down upon Broken Tooth.  The old beaver was oblivious of danger until Kazan was within twenty feet of him.  Naturally slow of movement on land, he stood for an instant stupefied.  Then he swung down from the tree as Kazan leaped upon him.  Over and over they rolled to the edge of the bank, carried on by the dog’s momentum.  In another moment the thick heavy body of the beaver had slipped like oil from under Kazan and Broken Tooth was safe in his element, two holes bitten clean through his fleshy tail.  Baffled