It was at about this time, the time when Ab had begun to develop from boyhood into strong and aspiring youth, that his family was increased from five to six by the addition of a singular character, Old Mok. This personage was bent and seemingly old, but he was younger than he looked, though he was not extremely fair to look upon. He had a shock of grizzled hair, a short, stiff, unpleasant beard, and the condition of one of his legs made him a cripple of an exaggerated type. He could hobble about and on great occasions make a journey of some length, but he was practically debarred from hunting. The extraordinary curvature of his twisted leg was, as usual in his time, the result of an encounter with some wild beast. The limb curved like a corkscrew and was so much shorter than the other leg that the man was really safe only when the walls of a cave enclosed him. But if his legs were weak his brain and arms were not. In that grizzled head was much intelligence and the arms were those of a great climber. His toes were clasping things and he was at home in a treetop. But he did not travel much. There was no need. Old Mok had special gifts, and they were such as made him a desirable friend among the cave men. He had, in his youth, been a mighty hunter and had so learned that he could tell wonderfully the ways of beasts and swimming things and the ways of slaying or eluding them. Best of all, he was such a fashioner of weapons as the valley had rarely known, and, because of this, was in great request as a cared-for inmate of almost any cave which hit his fancy. After his crippling he had drifted from one haven to another, never quite satisfied with what he found, and now he had come to live, as he supposed, with his old friend, One-Ear, until life should end. Despite his harshness of appearance--and neither of the two could ever afterward explain it--there was something about the grim old man which commended him to Ab from the very first. There was an occasional twinkle in the fierce old fellow's eye and sometimes a certain cackle in his clucking talk, which betokened not unkindliness toward a healthy youngster, and the two soon grew together, as often the young and old may do.