Joe had stopped only to let the mules rest and graze, and wherever that was he nibbled a cold snack from the food Emma had prepared for him. Then he slept, but he had purposely brought no blankets and he built no fire, because he did not want to oversleep. Though he was tired enough to doze wherever he lay down, the cold always awakened him. Never for an instant did he forget the fact that he had left his family camped, undefended, along the river. He must return to them at the earliest possible moment, for they were his to protect. Therefore, he let the mules have only the barest minimum of grazing and rest, and he drove himself as hard as he drove them. Though he slept little, he remained alert to the things about him. No man should travel in this country without a rifle, and he had left the rifle with Tad. Should any personal emergency arise, he would have to meet it as best he could. He didn't expect any; they'd come all this way and needed the rifle only for food. Joe smiled wryly. It always seemed that, when one lacked something, the need for it arose. He cantered the mules around a knoll, and both came to a sliding halt while they pricked their ears forward and blew their nostrils. No more than sixty yards away, staring intently at them, was an enormous bear. Joe swallowed hard. He was familiar with the little black bears of Missouri, but this was no black bear. Joe remembered vaguely that he had heard of white bears, or western grizzlies, and the bear was of a pale color. They were savage things and enormously strong. Certainly this one looked as though it could kill one or both of the mules without exerting itself unduly. Joe swung the mules, who needed no urging, and galloped them to the right. Glancing behind, he saw the bear running and for a moment he thought it was racing to cut him off. Then he grinned weakly and relaxed. All bears, he remembered, have rather poor hearing and sight. They have a keen sense of smell, but the wind had been blowing from the bear to Joe. Probably the grizzly hadn't even been aware of his presence until the mules started to run, and then he was as frightened as the mules. Or, Joe thought, as frightened as one Joe Tower. Reaching the abandoned wagon, he first gathered two piles of flat stones. One he arranged beneath the wagon's axle; the other he piled a few feet in front. He had remembered to cut a prying pole when he passed the grove of trees in which they had camped. Using one pile of stones as a fulcrum, he inserted the pole beneath the axle and lifted. Raising the front end of the wagon, Joe drove a forged stick over the prying pole to hold it. Then he built higher the stones beneath the axle. When the wheel no longer touched the earth, he took it off. Lifting the wagon's other side, he took that wheel too, and packed both on the horse mule. Should they break another wheel, he would not be caught without a spare.