Immediately the wolf sprang in again, with a courage scarcely compatible with lupine characteristics, ready to wage this unequal battle to the death. But his brave fight was tragically hopeless. For all that his hundred and fifty pounds were, every ounce, lightning muscle and vibrant sinew, it was as if a gopher had waged war with a lynx. Yet by the law of his wild heart he could not turn and flee. His master--his stalwart god whose words thrilled him to the uttermost depths--had given his orders, and he must obey them to the end. The second blow missed him also, but the third caught a small shrub that grew twenty feet beyond the dying fire. The shrub snapped off under the blow, and its branchy end smote the wolf across the head and neck. As if struck by a tornado he was hurled into the air, and curtailed and indirect though the blow was, he sprawled down stunned and insensible in the grass. The bear paused one instant; then lunged forth again. But the breath in which the wolf had stayed the charge had given Ben his chance. With a swift motion of his arm he had projected the single rifle shell into the chamber of the weapon. The stock snapped to his shoulder; and his keen, glittering eyes sought the sights. XXVIII Few wilderness adventures offer a more stern test to human nerves than the frightful rush of a maddened grizzly. It typifies all that is primal and savage in the wild: the insane rage that can find relief only in the cruel rending of flesh; the thundering power that no mere mortal strength can withstand. But Ben was a woodsman. He had been tried in the fire. He knew that not only his life, but that of the girl in the cavern depended upon this one shot; and it was wholly characteristic of Wolf Darby that his eye held true and his arm was steady as a vice of iron. He was aware that he must wait until the bear was almost upon him, in order to be sure to send the bullet home to a vital place. This alone was a test requiring no small measure of self-control. The instinct was to fire at once. In the moonlight it was difficult to see his sights: his only chance was to enlarge his target to the last, outer limit of safety. He aimed for the great throat, below the slavering jaw. His finger pressed back steadily against the trigger. The slightest flinching, the smallest motion might yet throw off his aim. The rifle spoke with a roar. But this wilderness battle was not yet done. The ball went straight home, down through the throat, mushrooming and plowing on into the neck, inflicting a wound that was bound to be mortal within a few seconds. The bear recoiled; but the mighty engine of its life was not yet destroyed. Its incalculable fonts of vitality had not yet run down.