Once more his pursuers were gaining on him; before long their scalping knives might be about his head.  He was the first to perceive us approaching, and it seemed to add fresh nerve to his legs.  Soon afterwards the Blackfeet caught sight of us.  The instant they did so they sprang forward, making a last desperate effort to overtake our friend; but perceiving that we had rifles ready, they well knew that, even should they succeed, we should make them pay dearly for the act.