"I got to put you under arrest, Mr. Elliot," he explained.

The loafers in the hotel drew closer.

"What for?" demanded Gordon, surprised.

"Doc thinks it will run to murder, I reckon."

The field agent was startled. "You mean—Macdonald?"

The brown man chewed his quid steadily. "You done guessed it."

"That's absurd, you know. What evidence have you got?"

"First off, you'd had trouble with him. It was common talk that when you and Mac met, guns were going to pop. You bought an automatic revolver at the Seattle & Kusiak Emporium two days ago. You was seen practising with it."

"He had threatened me."