The Night Horseman by Max Brand

Buck Daniels opened his eyes and sat bolt-upright in bed. He had dreamed the dream again, and this time, as always, he awakened before the end. He needed no rubbing of eyes to rouse his senses. If a shower of cold water had been dashed upon him he could not have rallied from sound slumber so suddenly. His first movement was to snatch his gun from under his mattress, not that he dreamed of needing it, but for some reason the pressure of the butt against his palm was reassuring. It was better than the grip of his friend -- a strong man.

It was the first grey of dawn, a light so feeble that it served merely to illuminate the darkness, so to speak. It fell with any power upon one thing alone, the bit of an old, dusty bridle that hung against the wall, and it made the steel glitter like a watchful eye. There was a great dryness in the throat of Buck Daniels; and his whole big body shook with the pounding of his heart.