The "Negro stable buck," Crooks, is perhaps the most marginalized character in Of Mice and Men. In fact, the epithet that introduces him to the reader does not refer to him as a man. A long-time employee, Crooks is, nevertheless, relegated to the stable where he must bunk down with the animals away from the other men who reside in the bunkhouse.
Filled with resentment of his treatment as he is obviously literate and neat, qualities that others do not possess, Crooks is hostile and defensive towards Lennie when he stands in the doorway fo the barn:
"You got no right to come in my room. This here's my room. Nobody got any right in here but me....I an't wanted in the bunk house, and you ain't wanted in my room."
But, when Crooks discerns that Lennie is child-like, he loses his defensiveness and taunts Lennie about the possibility of George's not returning from town, causing Lennie to become upset. Then, Crooks says, "Maybe you can see [understand] now."
S'pose you couldn't go into the bunk hous...A guy needs somebody--to be near him....A guy goes nuts if he ain't got nobody. Don't make no difference who the guy is, long's he's with you, I tell ya...I tell ya a guy gets too lonely an' he gets sick."
Later in the narrative of Chapter 4, Curley's wife appears in the doorway, breathing heavily, as though she has run to the barn. When she reveals that Curley has joined the others in town, it is clear that she, too, is lonely and craves attention. But, the wise Crooks encourages her to leave so that nothing will happen, saying, "We don't want no trouble."
"Well, I ain't giving you no trouble. Think I don't like to talk to somebody ever' once in a while? Think I like to stick in the house alla time?"
But she meets with aggression from the men, born of the their fear of Curley, the son of the boss who can have them fired. When she finally leaves, it is after she has greatly insulted them and threatened Crooks with hanging; the men depart after George returns and Crooks looks out where the men have gone.