To-day he placed the tallow and bran before Kazan, and the smile in his face gave way to a look of perplexity.  Kazan’s lips had drawn suddenly back.  A fierce snarl rolled deep in his throat.  The hair along his spine stood up.  His muscles twitched.  Instinctively the professor turned.  Sandy McTrigger had come up quietly behind him.  His brutal face wore a grin as he looked at Kazan.

“It’s a fool job—­tryin’ to make friends with him” he said.  Then he added, with a sudden interested gleam in his eyes, “When you startin’?”

“With first frost,” replied McGill.  “It ought to come soon.  I’m going to join Sergeant Conroy and his party at Fond du Lac by the first of October.”

“And you’re going up to Fond du Lac—­alone?” queried Sandy.  “Why don’t you take a man?”

The little professor laughed softly.

“Why?” he asked.  “I’ve been through the Athabasca waterways a dozen times, and know the trail as well as I know Broadway.  Besides, I like to be alone.  And the work isn’t too hard, with the currents all flowing to the north and east.”

Sandy was looking at the Dane, with his back to McGill.  An exultant gleam shot for an instant into his eyes.

“You’re taking the dogs?”

“Yes.”

Sandy lighted his pipe, and spoke like one strangely curious.

“Must cost a heap to take these trips o’ yourn, don’t it?”

“My last cost about seven thousand dollars.  This will cost five,” said McGill.

“Gawd!” breathed Sandy.  “An’ you carry all that along with you!  Ain’t you afraid—­something might happen—?”

The little professor was looking the other way now.  The carelessness in his face and manner changed.  His blue eyes grew a shade darker.  A hard smile which Sandy did not see hovered about his lips for an instant.  Then he turned, laughing.

“I’m a very light sleeper,” he said.  “A footstep at night rouses me.  Even a man’s breathing awakes me, when I make up my mind that I must be on my guard.  And, besides”—­he drew from his pocket a blue-steeled Savage automatic—­“I know how to use this.”  He pointed to a knot in the wall of the cabin.  “Observe,” he said.  Five times he fired at twenty paces, and when Sandy went up to look at the knot he gave a gasp.  There was one jagged hole where the knot had been.

“Pretty good,” he grinned.  “Most men couldn’t do better’n that with a rifle.”

When Sandy left, McGill followed him with a suspicious gleam in his eyes, and a curious smile on his lips.  Then he turned to Kazan.

“Guess you’ve got him figgered out about right, old man,” he laughed softly.  “I don’t blame you very much for wanting to get him by the throat.  Perhaps—­”