The Rustlers of Pecos County by Zane Grey — Read

I ran like one possessed of devils down that rough slope, hurdling the stones and crashing through the brush, with a sound in my ears that was not all the rush of the wind. When I reached a level I kept running; but something dragged at me. I slowed down to a walk. Never in my life had I been victim of such sensation. I must flee from something that was drawing me back. Apparently one side of my mind was unalterably fixed, while the other was a hurrying conglomeration of flashes of thought, reception of sensations. I could not get calm.

By and by, almost involuntarily, with a fleeting look backward as if in expectation of pursuit, I hurried faster on. Action seemed to make my state less oppressive; it eased the weight upon me. But the farther I went on, the harder it was to continue. I was turning my back upon love, happiness, success in life, perhaps on life itself. I was doing that, but my decision had not been absolute. There seemed no use to go on farther until I was absolutely sure of myself. I received a clear warning thought that such work as seemed haunting and driving me could never be carried out in the mood under which I labored. I hung on to that thought. Several times I slowed up, then stopped, only to tramp on again.