But in spite of his determination to "brace up," even the slight effort of crawling to the grateful shade bothered him so badly that, having reached it, he could only lie on his side and pant like an exhausted creature. All at once a sound was borne to his ears that made him sit up erect--the bright light of hope gleaming in his eyes. Heavy footsteps were coming toward him. The boy cared little whether the advancing individual was friend or foe. His coming meant food, at least; for surely no enemy could be so inhuman as to refuse nourishment to a boy in the pitiable condition of Rob Blake. "There's something queer about those footsteps, though," mused the boy, as the sounds drew nearer, accompanied by a sort of low, growling grumbling. What can it be? "Sounds like--like---- Great Scott! Silver Tip!" Into the small clearing on one side of which Rob lay beneath his sheltering bush, there had suddenly lumbered the half-legendary monarch of the Santa Catapinas. It was Silver Tip, the giant grizzly! For a second the monster's small, piglike eyes glared in blank astonishment at the encounter. He was hunting honey, and this sudden meeting with a white boy in the wildest part of his own particular domain evidently had struck him "in a heap," so to speak. The next instant, however, the expression of his wicked little optics changed to one of active malevolence. He swung his great bulk savagely about--like the giant heavings and swayings of a picketed elephant. The small spot of snow-white hair that gave him his name shone out on his dark, shaggy hide like a bull's-eye. It was right over his heart. If Rob had had a rifle, he could have pierced it as unerringly as a target. [Illustration: With a crazy yell, the boy leaped to his feet and rushed straight at his monstrous shaggy opponent.] But the lad was weaponless, and almost unconscious from fatigue and exhaustion. Indeed, delirium had been dangerously near when Silver Tip came lumbering into the clearing. The sight of the monster had tipped the delicately adjusted balance. With a crazy yell, the boy leaped to his feet and rushed straight at his monstrous shaggy opponent. In sheer astonishment, Silver Tip reared his immense bulk upward. "Ha, ha! I'll kill you, you old thief, you old murderer!" yelled Rob deliriously, as he hurled his slight form straight against the monstrous hairy tower of rugged strength. The great forepaws--armed with claws as sharp and heavy as chilled-steel chisels--extended. In another instant the lad would have been in the monster's death grip, when an intervention, as sudden as it was unexpected, occurred. CHAPTER XVIII. THE INDIAN AGENT.