Lonesome Dove, Volume 1 by Larry McMurtry

AUGUSTUS KEPT HIS PISTOL COCKED ALL NIGHT, once Pea Eye left. He watched the surface of the river closely, for the trick he hoped might work for Pea could also work for the Indians. They might put a log in the water and float down on him, using the log for cover. He tried to look and listen closely, a task not helped by the fact that he was shaking and feverish.

He expected the Indians to come sliding out of the water like big snakes, right in front of him, but none came, and as his fever mounted he began to mumble. From time to time he was half aware that he was delirious, but there was nothing he could do about it, and anyway he preferred the delirium to the tedium of waiting for the Indians to attack. One minute he would be trying to watch the black water, the next he would be back at Clara's. At times he saw her face vividly.