The novel opens with two men, George Milton and Lennie Small, walking to a nearby ranch where harvesting jobs are available. George, the smaller man, leads the way and makes the decisions for Lennie, a mentally handicapped giant. They stop at a stream for the evening, deciding to go to the ranch in the morning. Lennie, who loves to pet anything soft, has a dead mouse in his pocket. George takes the mouse away from Lennie and reminds him of the trouble Lennie got into in the last town they were in-he touched a girl's soft dress. George then reminds Lennie not to speak to anyone in the morning when they get to the ranch and cautions Lennie to return to this place by the river if anything bad happens at the ranch.
             When he has to take the dead mouse away from Lennie a second time, George chafes at the hardship of taking care of Lennie. After calming his anger, George relents and promises Lennie they will try to find him a puppy; then he tells Lennie about their dream of having a little farm where they can be their own boss and nobody can tell them what to do, where Lennie will tend their rabbits, and where they will "live off the fatta the lan'." Lennie has heard this story so often he can repeat it by heart. And George emphasizes that this dream and their relationship make them different from other guys who don't have anyone or a place of their own. They settle down and sleep for the night.
             The next morning at the ranch, the boss becomes suspicious when George answers all the questions and Lennie does not talk. George explains that Lennie is not bright but is a tremendous worker. They also meet Candy, an old swamper with a sheep dog; Crooks, the black stable hand; the boss' son Curley, who is an amateur boxer and has a bad temper; Curley's wife, who has a reputation as a "tart"; Carlson, another ranch hand; and Slim, the chief mule skinner. Upon seeing Curley's wife, Lennie is fascinated with her and George warns him to stay away from ...