Two migrant field workers in California during the Great Depression—George Milton, an intelligent and cynical man, and Lennie Small, an ironically-named man of large stature and immense strength but limited mental abilities—come to a ranch near Soledad southeast of Salinas, California to "work up a stake." They hope to one day attain their shared dream of settling down on their own piece of land. Lennie's part of the dream, which he never tires of hearing George describe, is merely to tend to (and touch) soft rabbits on the farm. George protects Lennie at the beginning by telling him that if Lennie gets into trouble George won't let him "tend them rabbits." They are fleeing from their previous employment in Weed where they were run out of town after Lennie's love of stroking soft things resulted in an accusation of attempted rape when he touched a young woman's dress.
At the ranch, the dream appears to move closer to reality. Candy, the aged, one-handed ranch-hand, even offers to pitch in with Lennie and George so they can buy the farm by the end of the month. The dream crashes when Lennie accidentally kills the young and attractive wife of Curley, the ranch owner's son, while trying to stroke her hair. A lynch mob led by Curley gathers. George, realizing he is doomed to a life of loneliness and despair like the rest of the migrant workers and wanting to spare Lennie a painful death at the hands of the vengeful and violent Curley, shoots Lennie in the back of the head before the mob can find him after they had recited their dreams of owning their own land.
Steinbeck emphasizes dreams throughout the book. George aspires for independence, to be his own boss, to have a homestead, and most importantly to be "somebody".