Already, looking back, he saw the posse changing their saddles to fifteen fresh mounts, and he headed Satan across the Wago Hills, West and South.
It was hot work.

Even the steel-wire muscles of Black Bart were weakening under the tremendous labors of that day, and as he scouted ahead his head was low and his red tongue lolled, and surest sign of all, the bushy tail drooped; yet it was time to make a new call upon both wolf-dog and horse, for the posse was racing after him as before, giving even the fresh, willing mounts the urge of spurs and quirts.

He ran his hand down the dripping neck and shoulder of Satan; he called to him; and with a snort the stallion responded.

He felt the quiver as the muscles tightened for the work; he felt the settling as Satan lengthened to racing speed.
Through the Wago Hills, then, with Bart picking the way as before, and never a falter in the sweep of Satan's running.

If his head was a little lower, if his ears lay flat, only the master knew the meaning, and still, when he spoke, the glistening ears pricked up, and they bounded on to a greater speed than before.