So sudden was it, and so unexpected, that Buck was taken aback. He saw Spitz run out his scarlet tongue in a way he had of laughing; and he saw Francois, swinging an axe, spring into the mess of dogs. Three men with clubs were helping him to scatter them. It did not take long. Two minutes from the time Curly went down, the last of her assailants were clubbed off. But she lay there limp and lifeless in the bloody, trampled snow, almost literally torn to pieces, the swart half-breed standing over her and cursing horribly. The scene often came back to Buck to trouble him in his sleep. So that was the way. No fair play. Once down, that was the end of you. Well, he would see to it that he never went down. Spitz ran out his tongue and laughed again, and from that moment Buck hated him with a bitter and deathless hatred. 
Before he had recovered from the shock caused by the tragic passing of Curly, he received another shock. Francois fastened upon him an arrangement of straps and buckles. It was a harness, such as he had seen the grooms put on the horses at home. And as he had seen horses work, so he was set to work, hauling Francois on a sled to the forest that fringed the valley, and returning with a load of firewood. Though his dignity was sorely hurt by thus being made a draught animal, he was too wise to rebel. He buckled down with a will and did his best, though it was all new and strange. Francois was stem, demanding instant obedience, and by virtue of his whip receiving instant obedience; while Dave, who was an experienced wheeler, nipped Buck's hind quarters whenever he was in error. Spitz was the leader, likewise experienced, and while he could not always get at Buck, he growled sharp reproof now and again, or cunningly threw his weight in the traces to jerk Buck into the way he should go. Buck learned easily, and under the combined tuition of his two mates and Francois made remarkable progress. Ere they returned to camp he knew enough to stop at "ho," to go ahead at "mush," to swing wide on the bends, and to keep clear of the wheeler when the loaded sled shot downhill at their heels. 