As the young cub grows, he becomes more adventuresome, and one time when the she-wolf is out hunting for food, the cub wanders out of the cave. But, as will often happen, without his knowing why, some instinctive fear drives him back into the shelter of the cave; this is a fear that is "the legacy of the wild which no animal may escape." On subsequent explorations outside of the cave, the cub gains more and more courage, and he travels farther and farther away from the lair. Once, by accident, he stumbles into a nest of baby ptarmigans. At first, he is frightened, and then his instincts take over, and, in London's words, the cub's "jaws closed . . . and there was a crunching of fragile bones and warm blood ran from his mouth. The taste of it was good." The gray cub eats the entire brood, and then, as he leaves the nest as a conqueror, he is suddenly attacked by the ptarmigan hen. "It was his first battle. He was elated. . . . he was no longer afraid of anything." But he is about to lose the battle, when, by a stroke of luck, a great hawk suddenly swoops down and snatches up the mother ptarmigan and carries her away, thus saving the gray cub from certain death. It is a good learning lesson for him: kill or be killed. It is the law of the wild. Exploring farther, the gray cub falls into a river and almost drowns before he is able to crawl out. Thus he learns another lesson about survival — water can be dangerous.
The gray cub next comes upon a young weasel, which is so small that the little cub begins to play with it. Suddenly, however, the mother weasel appears, and even though she is even smaller than the gray cub, the cub quickly discovers that she is savage and fierce, and that she would have killed him had not the cub's mother, the she-wolf, appeared just in time to save him.
