The two horses went wild, as their riders had half expected them to do.

They lunged away from the horror behind them, and the slack ropes tightened with a jerk.

Both were good rope horses, and the strain of the ropes almost recalled them to sanity and their training; at least they held the ropes tight for a few seconds, so that the machine jumped ahead and veered toward the firmer soil beside the trail, in response to Pete's turn of the wheel.
Then Pard looked back and saw the thing coming after him, and tried to bolt.

When he found that he could not, because of the rope, he bucked as he had not done since he was a half-broken broncho.

That started Lite Avery's horse to pitching; and Pete, absorbed in watching what would have made a great picture, forgot to shut off the gas.
Robert Grant Burns picked himself out of the sand where he had sprawled at the first wild lunge of the machine, and saw Pete Lowry, humped over the wheel like any speed demon, go lurching off across the hollow in the wake of two fear-crazed animals, that threatened at any instant to bolt off at an angle that would overturn the car.
Then Lite let his rope slip from the saddle-horn and spurred his horse to one side, out of the danger zone of the other, while he felt frantically in his pockets for his knife.
"Don't you cut my rope," Jean warned, when she saw him come plunging toward her, knife in hand.