That, by all the rules in the northland game of which Jan was a past-master, brought Sourdough within seconds of his end.  The throat was exposed; the deadly underhold, given which no dog breathing could evade Jan.

And at that moment came Dick’s voice in very urgent and meaning exhortation: 

“Back, Jan!  Don’t kill him.  He’s too old.  Back—­here—­Jan!”

Jan’s jaws had parted for the killing grip.  His whole frame was perfectly poised for the thrust from which no dog placed as Sourdough was could possibly escape.  A swift shudder passed through him as though his sovereign’s words reached him on a cold blast, and, stiff-legged, wondering, his shoulder hair all erect, and jaws still parted for the fray, Jan stepped back to Dick’s side.

“You’ll have to keep that old tough in to heel if you mean to save him, Sergeant,” said Captain Arnutt.  “You can’t expect Jan to lie down to him.  Why don’t you keep him in to heel, man?”

The sergeant passed on, saluting, without a word.  Doubtless he had liefer far that Captain Arnutt had hit him in the face.  But, when all is said, no words could hurt this curious monomaniac now, after that which he had seen with his own eyes and that which he now saw.

Complete enlightenment had come to old Sourdough in one fraction of a moment.  In the moment when he reached earth, on his back, flung there by his impact with the calculated screwing thrust of Jan’s massive shoulder, Sourdough knew that his day was over.  He expected to die then and there, and was prepared to die.  Contact with Jan had told him in a flash things which could not be written in a page.  He tasted in that moment the cold-drawn, pitiless efficiency of the methods of the northland wild, and realized that he could no more stand against this new Jan than a lady’s house-bred lap-dog could have stood against himself.  As his feet left the ground his life was ended, as Sourdough saw it.

And then had come Jan’s miraculous, shuddering withdrawal, wholly inexplicable, chilling to the heart in its uncanny unexpectedness.  Sourdough mechanically regained his footing, and then with low-hung head, inward-curling tail, and crouching shoulders he slunk away at the heel of his bitterly disappointed master.  The collapse of this old invincible within a few seconds was a rather horrid sight and a very strange and startling one.

From that hour Sourdough was never again seen in the precincts of the R.N.W.M.P. barracks, and, though many people puzzled over the old dog’s disappearance, none ever knew what became of him.  The sergeant had been for some time entitled to retire from the service.  That night he obtained his commanding officer’s permission to do so.

XXXIX

HOW JAN CAME HOME

Captain Arnutt proved himself a friend indeed to Dick Vaughan.  Once he had come to understand the position, he fully sympathized with Dick’s wish to leave the service at once and return to England.  That sympathy he proceeded forthwith to translate into action, and within the month Sergeant-Inspector Dick Vaughan had received his discharge and booked his passage—­with Jan’s—­for England.