Classicly

Matthews climbed to his feet and walked slowly over to the edge of the rocks where the camp was situated. It was on the edge of the desert, and down below sand and sage stretched for miles in the pale moonlight. On either side he could see the flicker of the other campfires, forming a huge circle, many miles in diameter. As he stood watching, his ear unconsciously picked up the rustle of silent footsteps on the trail leading to the nearest campfire away—the guard-line which closed the circle tight.