The shack lurched forward after the straining horses.

Once it was fairly started it moved more easily than you might think it could do, upon crude runners made of cottonwood logs eight inches or so in diameter and long enough for cross pieces bolted in front and rear.

The horses pulled it easily with the ropes tied to the saddle-horns, just as they had many times pulled the roundup wagons across mirey creeks or up steep slopes; just as they had many times pulled stubborn cattle or dead cattle--just as they had been trained to pull anything and everything their masters chose to attach to their ropes.
Within, Owens called to them and cursed them.

When they had just gained an even pace, he emptied his revolver through the four sides of the shack.

But he did not know where they were, exactly, so that he was compelled to shoot at random.