Invisible Man is the story of a young, college-educated black man struggling to survive and succeed in a racially divided society that refuses to see him as a human being. Told in the form of a first-person narrative, Invisible Man traces the nameless narrator's physical and psychological journey from blind ignorance to enlightened awareness — or, according to the author, "from Purpose to Passion to Perception" — through a series of flashbacks in the forms of dreams and memories. Set in the U.S. during the pre-Civil Rights era when segregation laws barred black Americans from enjoying the same basic human rights as their white counterparts, the novel opens in the South (Greenwood, South Carolina), although the majority of the action takes place in the North (Harlem, New York).
In the Prologue, the narrator — speaking to us from his underground hideout in the basement (coal cellar) of a whites-only apartment building — reminisces about his life as an invisible man. Now in his 40s, he recalls a time when he was a naïve young man, eager to become a renowned educator and orator. The narrator begins his story by recalling his high school graduation speech, which attracted the attention of the white school superintendent who invites him to give the same speech at a local hotel to the town's leading white citizens. But when he arrives at the hotel, the narrator is forced to participate in a brutal blindfolded boxing match (the "battle royal") with nine of his classmates, an event, which, he discovers, is part of the evening's entertainment for the "smoker" (a kind of stag party). The entertainment also includes a sensuous dance by a naked blonde woman, and the boys are forced to watch. The boxing match is followed by a humiliating event: The boys must scramble for what appear to be gold coins on an electrified rug (but, which turn out to be only worthless brass tokens). Then the narrator — now bruised and bleeding — is finally allowed to give his speech in front of the drunken white men who largely ignore him until he accidentally uses the phrase "social equality" instead of "social responsibility" to describe the role of blacks in America. At the end of his speech — despite his degrading and humiliating ordeal — the narrator proudly accepts his prize: a calfskin briefcase containing a scholarship to the state college for Negroes.
That night, the narrator's dead grandfather — a former slave — appears in a dream, ordering him to open the briefcase and look inside. Instead of the scholarship, the briefcase contains a note that reads, "Keep This Nigger Boy Running." The dream sets the stage. For the next 20 years of his life, the narrator stumbles blindly through life, never stopping to question why he is always kept running by people — both black and white — who profess to guide and direct him, but who ultimately exploit him and betray his trust.
Focusing on the events of one fateful day, the narrator then recalls his college days. Assigned to chauffeur Mr. Norton, a prominent white visiting trustee, around the campus, the narrator follows Mr. Norton's orders and takes him to visit two sites in the nearby black neighborhood — the cabin of Jim Trueblood, a local sharecropper, and the Golden Day, a disreputable bar/half-way house for shell-shocked World War I veterans. The narrator, however, is expelled from his beloved college for taking Mr. Norton to these places and sent to New York, armed with seven letters from his dean (Dr. Bledsoe). The letters, he believed, are letters of recommendation, but are in reality letters confirming his expulsion.
Arriving in New York City, the narrator is amazed by what he perceives to be unlimited freedom for blacks. He is especially intrigued by a black West Indian man (later identified as Ras the Exhorter) whom he first encounters addressing a group of men and women on the streets of Harlem, urging them to work together to unite their black community. But the narrator's excitement soon turns to disillusionment as he discovers that the North presents the same barriers to black achievement as the South.
Realizing that he cannot return to college, the narrator accepts a job at a paint factory famous for its optic white paint, unaware that he is one of several blacks hired to replace white workers out on strike. Nearly killed in a factory explosion, the narrator subsequently undergoes a grueling ordeal at the paint factory hospital, where he finds himself the object of a strange experiment by the hospital's white doctors.
Following his release from the hospital, the narrator finds refuge in the home of Mary Rambo, a kind and generous black woman, who feeds him and nurses him back to health. Although grateful to Mary, whom he acknowledges as his only friend, the narrator — anxious to earn a living and do something with his life — eventually leaves Mary to join the Brotherhood, a political organization that professes to be dedicated to achieving equality for all people. Under the guidance of the Brotherhood and its leader, Brother Jack, the narrator becomes an accomplished speaker and leader of the Harlem District. He also has an abortive liaison with Sybil, a sexually frustrated white woman who sees him as the embodiment of the stereotypical black man endowed with extraordinary sexual prowess.
But after the tragic death of his friend Tod Clifton, a charismatic young black "Brother" who is shot by a white policeman, the narrator becomes disillusioned with the disparity between what the organization preaches and what its leaders practice. As a result, he decides to leave the Brotherhood, headquartered in an affluent section of Manhattan, and returns to Harlem where he is confronted by Ras the Exhorter (now Ras the Destroyer) who accuses him of betraying the black community. To escape the wrath of Ras and his men, the narrator disguises himself by donning a hat and dark glasses. In disguise, he is repeatedly mistaken for someone named Rinehart, a con man who uses his invisibility to his own advantage.
The narrator discovers that the Harlem community has erupted in violence. Eager to demonstrate that he is no longer part of the Brotherhood, the narrator allows himself to be drawn into the violence and chaos of the Harlem riot and participates in the burning of a Harlem tenement. Later, as he flees the scene of the burning building and tries to find his way back to Mary's, two white men with baseball bats pursue him. To escape his assailants, he leaps into a manhole, which lands him in his underground hideout.
For the next several days the sick and delusional narrator suffers horrific nightmares in which he is captured and castrated by a group of men led by Brother Jack. Finally able to let go of his painful past — symbolized by the various items in his briefcase — the narrator discovers that writing down his experiences enables him to release his hatred and rediscover his love of life.