Nothing in the wide world could induce that wild heart to accept more than one master--more than one friend.

For Satan there was in the animal world Black Bart, and in the world of men, Dan Barry.

These were enough.

For all the rest he kept the disdainful speed of his slender legs or the terror of his teeth and trampling hoofs.

Even if she could have induced the stallion to eat from her hand she could never have made him willing to trust himself to her guidance.
Some such thing she felt that she must accomplish with Black Bart.