He went back riding at a long lope, as though time was precious to him.
Mary V watched until she saw him emerge out of that hollow and duck into another which led toward the northwest and, if he followed it, would bring him out near the head of Dry Gulch, which was several miles nearer the Rolling R home ranch than was the ridge where she stood.

When he had gone, she turned again to see where the Mexican was going.

The Mexican, she discovered, was going east as fast as his horse could carry him without dropping dead in that heat; and he, also, was keeping to the hollows.
"Here's a pretty howdy-do!" said Mary V to the palpitating atmosphere.
"I'm just going to tell dad about Tex sneaking away down here to meet Mexicans and things on the sly! I never did like that Tex.

I don't like his eyes.

You can't see into them at all.