He wanted to know about Quade and Culver Rann.
"Blackton is such a ridiculously forgetful fellow at times that I don't want to rouse his alarm," he said to MacDonald as they were riding toward the corral a few minutes later.

"He might let something out to Joanne and his wife, and I've got reasons--mighty good reasons, Mac--for keeping this affair as quiet as possible.

We'll have to discover what Rann and Quade are doing ourselves." MacDonald edged his horse in nearer to Aldous.
"See here, Johnny, boy--tell me what's in your mind ?" Aldous looked into the grizzled face, and there was something in the glow of the old mountaineer's eyes that made him think of a father.
"You know, Mac." Old Donald nodded.
"Yes, I guess I do, Johnny," he said in a low voice.

"You think of Mis' Joanne as I used to--to--think of _her_.

I guess I know.