All that Thornton had hinted flashed into his mind. Sandy was not to be trusted, Thornton had told his father. If they placed any dependence on the young Scotchman they would some time regret it. Had Sandy deceived him? What possible object could he have, Donald asked himself, in so quietly departing with the sheep and leaving him behind? At least he had left the tent. Had he taken the food and rifles with him? With beating heart Donald scrambled for his match-box and made a light. No, there was the knapsack of provisions, the saucepan, the coffee-pot! In the corner, too, stood his own rifle. But Sandy's rifle was missing. Donald reflected a moment. Sandy must be coming back. Ah, that was it! But where had he gone? Why should he rise up in the middle of the night, take the flock and dogs, and steal off in this noiseless fashion? The boy could not solve the enigma. For the present, at least, there was nothing to be done. He glanced at his watch. It was three o'clock. He turned into his sleeping-bag again, having first taken the precaution to put his rifle within easy reach. Yet try as he would he could not sleep. His eyes stared, broad awake, at the shadowy dome of the tent. He wished it was day. As he lay there straining his ears for the cadence of approaching herd-bells he was conscious of a muffled sound--a dull, soft footfall, as if some one was loitering stealthily about the tent. He heard it again. Then he could distinctly hear a sniffing at the corner of the tent near which the provisions lay. Donald's heart leaped to his throat. He could feel the blood pounding under his ears. Who was coming so near with that velvety tread? Noiselessly he wriggled out of his sleeping-bag and stood behind the flap of the tent, rifle in hand. Then he heard the unmistakable panting of some heavy creature--some creature so close to him that he could detect the rhythm of every breath it drew. Shaking in every limb he stole a look outside. Just beside the opening of his shelter he could see, clearly defined in the moonlight, a thick, dark shadow outlined on the grass. It was cast by some beast that was halting near the doorway. In another second it would be upon him. The boy caught his breath. There was no time to think. Raising his rifle, he fired at the great dark mass. Again he fired! Had he struck the mark? Another instant would tell. The creature would either roll over wounded, or would spring upon him. He jammed back the trigger of his rifle. The tremor that had swept over him at first now left his hand. His arm was perfectly steady, his blood swinging in quick throbs through his body. He fired a third time. There was a heavy thud, the rolling of a black mass on the ground, a gasp, a growl! Then all was quiet. Still Donald dared not take any chances. He poured another round of shot into his victim. It did not move. Then cautiously he crept outside, his rifle tight in his grasp.