Max Brand 
The Black Rider 

The Black Rider by Max Brand is about the adventures of rancher Senor Francisco Torreno, who lives only for his son and daughter-in-law. One day, Senor Torreno and his son hear a flute in the distance, only to find a mysterious and mute Native American with fateful advice. Excerpt: ”I mean that the horse is my slave, señor.’ ‘By the heavens!’ broke out Torreño. ‘The fellow speaks French, also. Better French than I use myself!’ ‘Wait, wait!’ said the girl in a hurried voice, raising her hand to stop interruptions, and staring fixedly at the Indian. ‘He has something more to say.’