of which he was at pains to make no show. For almost immediately he began to whistle softly, idly, his eyes roving carelessly across the wall while he tilted back in his chair. Dan dropped his hand close to the butt of his gun. Instantly, the eyes of Buck flashed down and centered on Dan for an instant of keen scrutiny. Certainly Buck had connected that mention of the black horse and the wolf-dog with a disturbing idea.
When they went to their room—a room in which there was no bed and they had to roll down their blankets on the floor—Dan opened the window and commenced to whistle one of his own wild tunes. It seemed to Calder that there was a break in that music here and there, and a few notes grouped together like a call. In a moment a shadowy figure leaped through the window, and Black Bart landed on the floor with soft padding feet.
Recovering from his start Calder cursed softly.
"What's the main idea?" he asked.
Dan made a signal for a lower tone.
"There ain't no idea," he answered, "but these Daniels people—do you know anything about them?"
"No. Why?"
"They interest me, that's all."
"Anything wrong?"
