They did not discover him.

Ferguson stood near Leviatt, an arm's length distant, his hands on his hips.

Perhaps his eyes were more alert than those of the other men, his lips in a straighter line.
But apparently he knew no more of this mystery than any of the others.
And now Leviatt's voice rose again, insolent, carrying an unmistakable personal application.
"Stafford hires a stray-man," he said, sneering.

"This man claims to have been bit by a rattler an' lays up over night in Ben Radford's cabin--makin' love to Mary Radford." Ferguson turned his head slightly, surveying the range boss with a cold, alert eye.
"A little while ago," he said evenly, "I heard a man inside tellin' about some of the boys learnin' their lessons from a girl over on Bear Flat.

I reckon, Leviatt, that you've been over there to learn your'n.
An' now you've got to let these boys know----!" Just a rustle it was--a snake-like motion.