Steinbeck's use of dialogue is where I think that the intensity of the moment in chapter four becomes so clearly evident.  Steinbeck has constructed a verbal tapestry filled with dreams, hopes, and aspirations as Candy has detailed to Crooks his shared dream with George and Lennie.  At this, Crooks wants in, representing the power of dreams even to the powerless.  This emotional timbre is completely undercut with the ferocity and venom that Curley's wife uses to cut down Candy and Crooks.  The fact that she openly refers to lynching and essentially tells Crooks that there is nothing stopping her from getting him killed as a man of color is particularly shocking.  The use of the "N" word in such a free and open manner is both shocking and hurtful in so far as Steinbeck honestly depicts the struggle for those who are economically and racially marginalized in America of the time.  When Candy's defense fails, the shock of the moment is that the reader becomes aware at how frail dreams are in such a condition as to where the characters live.  The shock to the reader is how easily the hopes and dreams that had been cultivated for some time can be dashed by external reality, in the form of the truthful yet hurtful comments of Curley's wife.