There was only one thing to guide them on their course.

Where the western hills raised their heights toward the sky, their outline showed darker than the surrounding night.
From this wall of black, Mart's force steered a diagonal course that would lead to the center of the canyon's mouth.

Once in the canyon, out of range of the house and among the sheep, lanterns and fires would provide light enough for the men's purpose.
It is not likely that there was an idea of poetic justice in the mind of Mart Cooley; a thought that in stampeding the sheep he was repaying the sheepmen in their own coin for stampeding the cattle, repaying them with the death of the victims added as interest.
The plan seemed to be working out easily--too easily.

Then, from one of the foremost rider's mounts, came the shrill neigh of a horse in pain, and the thudding of the animal's hoofs as it shied violently, for it had collided with the barbed wire fence.

This was Mart's first intimation that there was a fence, but he had no time to think that he had been matched in cleverness by Donald Spellman, for things began to happen.
First came the sound of a cowbell.