opening my mouth too wide--as I've
been warned not to."

"Who warned you?"

The question came sharp and direct.

"Why, O'Brien. You see, I went down to the saloon after I'd searched
the ranch for Charlie, and asked if he had been there. O'Brien was
shutting up. He said he had been there, but had gone. Then he told me
where I'd be likely to find him, but warned me not to open my mouth
wide--till I'd found him. Said I'd likely find him somewhere around
that pine. Said he'd likely be collecting some money around there.

"Well, I set out to make the pine, and I didn't wonder at things for
awhile. It wasn't till I got near it, and I saw the moon get up, and,
in its light, saw Charlie in the distance near the pine, that this
mystery thing got hold of me. It came on me when I hollered to him,
and, as a result of it, saw him vanish like a ghost. But----"

"You called to him?"

The girl's question again came sharply, but this time with an air of
deep contemplation.

"Yes. But I didn't get time to think about it. Just as I'd shouted two
horsemen scrambled out of the bush beside me. One of 'em was Fyles.
The other I didn't know. He'd got three stripes on his arm."

"Sergeant McBain," put in the woman quietly.

"You know him?"

Kate shrugged.

"We all know him about here."

Bill nodded.

"Fyles cursed me for a fool for hollering out. Said he'd been watching
that 'tough,' and didn't want to lose sight of him. I got riled. I
told him a few things, and said I'd a right to hail my brother any old
time. Then he changed around and said he was sorry, and asked me if I
was sure it was my brother. When I told him 'yes,' he thanked me for
putting him wise, and said I'd saved him a deal of unnecessary
trouble. Said there was no more need to watch him--seeing he was my
brother. That's when he told me about the storm, and I hit my short
cut, and, finally, reached--the river. Now, what was he watching for,
and who did he mistake Charlie for? What's the meaning of the whole
thing? Why did O'Brien warn me? These are the things that get me
puzzled to death. Maybe you can tell me--can help me out?"

He waited, confidently expecting an explanation that would clear up
all the mystery, but none was forthcoming. Instead, when Kate finally
replied, there was an almost peevish complaint in her tone.

"I wish you had taken O'Brien's warning more to heart," she said.
"Maybe you've done a lot of harm to-night. I can't tell--not yet."