Zane's manner.

Alfred well knew that the Colonel, if he found Betty had really been insulted, would call him out and kill him.Col.Zane spoke quietly, ever kindly, but there was an undercurrent of intense feeling in his voice, a certain deadly intent which boded ill to anyone who might cross him at that moment.
Alfred's first impulse was a reckless desire to tell Col.

Zane he had nothing to explain and that he stood ready to give any satisfaction in his power.

But he wisely thought better of this.

It struck him that this would not be fair, for no matter what the girl had done the Colonel had always been his friend.