From the book:
A FACE haunted Cameron - a woman's face. It was there in the white heart of the dying campfire; it hung in the shadows that hovered over the flickering light; it drifted in the darkness beyond. This hour, when the day had closed and the lonely desert night set in with its dead silence, was one in which Cameron's mind was thronged with memories of a time long past - of a home back in Peoria, of a woman he had wronged and lost, and loved too late. He was a prospector for gold, a hunter of solitude, a lover of the drear, rock-ribbed infinitude, because he wanted to be alone to remember. A sound disturbed Cameron's reflections. He bent his head listening. A soft wind fanned the paling embers, blew sparks and white ashes and thin smoke away into the enshrouding circle of blackness. His burro did not appear to be moving about. The quiet split to the cry of a coyote. It rose strange, wild, mournful - not the howl of a prowling upland beast baying the campfire or barking at a lonely prospector, but the wail of a wolf, full-voiced, crying out the meaning of the desert and the night.