John Steinbeck's Of Mice and Men, written in 1937, deals with the experiences of two best friends, George Milton and Lennie Small. After Lennie gets into trouble in the California town of Weed, the two men flee southward and work at a barley farm near Soledad, California. During their stay on the farm, Lennie, who is physically very strong but mentally challenged, accidentally kills the wife of Curley, the son of the farm's boss.
George knows that Curley and the other men on the farm will kill Lennie, so George secretly takes one of the other men's guns and finds Lennie near the Salinas River, where they had initially stopped before going on to the farm. George and Lennie sit together and George tells Lennie about their dream farm, just as he has many times before. While Lennie listens, George takes the gun and shoots Lennie in the back of the head:
George raised the gun and steadied it, and he brought the muzzle of it close to the back of Lennie’s head. The hand shook violently, but his face set and his hand steadied. He pulled the trigger. The crash of the shot rolled up the hills and rolled down again. Lennie jarred, and then settled slowly forward to the sand, and he lay without quivering.
The novel ends with another of the farm workers telling George that he had to kill Lennie.