She did not look at him.  She did not speak.  There seethed in her a loathing and a disgust beyond expression.

“Guess you forgot that a fellow can sometimes hear even when he can’t see.  Since I’m chaperooning you I’ll make out to be there next time you meet a good-looking lady-killer.  Funny, the difference it makes, being your brother.  You ain’t seen me since you was a kid, but you plumb forgot to kiss me.”

There was a note in his voice she had not heard before, some hint of leering ribaldry in the thick laugh that for the first time stirred unease in her heart.  She did not know that the desperate, wild-animal fear in him, so overpowering that everything else had been pushed to the background, had obscured certain phases of him that made her presence here such a danger as she could not yet conceive.  That fear was now lifting, and the peril loomed imminent.

He put his arm along the back of the seat and grinned at her from his loose-lipped mouth.

“But o’ course it ain’t too late to begin now, my dearie.”

Her fearless level eyes met squarely his shifty ones and read there something she could dread without understanding, something that was an undefined sacrilege of her sweet purity.  For woman-like her instinct leaped beyond reason.

“Take down your arm,” she ordered.

“Oh, I don’t know, sis.  I reckon your brother—­”

“You’re no brother of mine,” she broke in.  “At most it is an accident of birth I disown.  I’ll have no relationship with you of any sort.”

“Is that why you’re driving with me to Mexico?” he jeered.

“I made a mistake in trying to save you.  If it were to do over again I should not lift a hand.”

“You wouldn’t, eh?”

There was something almost wolfish in the facial malignity that distorted him.

“Not a finger.”

“Perhaps you’d give me up now if you had a chance?”

“I would if I did what was right.”

“And you’d sure want to do what was right,” he snarled.

“Take down your arm,” she ordered again, a dangerous glitter in her eyes.

He thrust his evil face close to hers and showed his teeth in a blind rage that forgot everything else.

“Listen here, you little locoed baby.  I got something to tell you that’ll make your hair curl.  You’re right, I ain’t your brother.  I’m Nick Struve—­ Wolf Struve if you like that better.  I lied you into believing me your brother, who ain’t ever been anything but a skim-milk quitter.  He’s dead back there in the cactus somewhere, and I killed him!”

Terror flooded her eyes.  Her very breathing hung suspended.  She gazed at him in a frozen fascination of horror.

“Killed him because he gave me away seven years ago and was gittin’ ready to round on me again.  Folks don’t live long that play Wolf Struve for a lamb.  A wolf!  That’s what I am, a born wolf, and don’t you forget it.”