Grant Wiggins has been teaching on a plantation outside Bayonne, Louisiana, for several years when a slow-witted man named Jefferson is convicted of murder and sentenced to death. Jefferson claims he is innocent of the crime. He says he was on his way to a bar, but changed his mind and decided to tag along with two men who were on their way to a liquor store. Upon arriving there, the two men began arguing with the storeowner, and a shootout ensued. The storeowner and the two men died, and Jefferson remained at the scene of the crime. He was arrested and tried for murder. Jefferson’s lawyer argues in court that Jefferson is nothing but a poor fool, hardly more worthwhile than a hog, and therefore incapable of plotting such a scheme. The jury quickly brings back a guilty verdict.
Upon hearing the lawyer’s speech, Jefferson’s godmother, Miss Emma, resolves to help Jefferson die like a man, not a hog. She asks Grant to help her, knowing that he will resist. Grant left many years prior to attend college, and he returned an educated man. He deplores the injustices done to his fellow black men, but he does not want to get involved in Jefferson’s case. However, after considerable pressure from his aunt, Tante Lou, he agrees to try to help Jefferson. Grant, Miss Emma, and Grant’s aunt go to visit Jefferson in his cell, and they discover that he too heard the lawyer’s words and has taken them to heart. Silent and moody, Jefferson resists Grant’s feeble attempts to reach him. The three visitors spend an uncomfortable hour in the cell and then leave.
During the next few visits, Jefferson continues to frustrate Grant’s attempts to communicate. When Grant attempts to teach Jefferson about dignity, Jefferson insists that dignity is for “youmans,” not hogs. He eats and snuffles in imitation of a hog and tries to anger Grant with stubbornness and malice, but Grant maintains his patience. Each hour-long visit ends in failure, but Grant continues to try to reach Jefferson. On his fourth visit, Grant sparks a conversation with Jefferson about his final meal. Jefferson admits that he wants a gallon of vanilla ice cream because, although he loves ice cream, he has never had more than a thimbleful at a time. This admission begins to break down the barrier between the two men. Grant borrows money from some townspeople and buys Jefferson a small radio. On his next visit, he brings Jefferson a notebook and asks him to write down whatever thoughts come to his mind. Jefferson promises to do so, and by Grant’s next visit, Jefferson has filled most of a page with thoughts concerning the difference between hogs and men.
Grant’s relationships with his girlfriend Vivian and with Reverend Ambrose begin to intensify. Despite her love for Grant, Vivian dislikes his tendency to think only of himself, showing little regard for her needs. Grant uses Vivian to escape the troubles of his life, and he continually suggests that they run away from their hometown and their past in the South. The Reverend Ambrose, himself unable to reach Jefferson, urges Grant to put aside his atheistic beliefs and help save not just Jefferson’s character, but his soul. The Reverend declares that Grant must learn to tell lies for the good of others.
Grant focuses his energy on Jefferson and tries to explain the importance of Jefferson’s death. Jefferson asks Grant if he believes in heaven and Grant replies that he does not, although he qualifies this remark by saying that his atheism does not make him a good man. In fact, Grant says, Jefferson will save even Grant’s atheistic soul if he carries the cross for the sinners on earth. Grant explains that the black community in the quarter has spent centuries enslaved to white men, and that when Jefferson’s attorney called him a hog, he attacked the will and intelligence of the entire black society. In consequence, Jefferson now has the opportunity to stand up for his community. He has become a symbol to his people, and the manner in which he faces his death will bear on their self--confidence and potential.
Over the next few weeks, Jefferson continues to write in his journal. In March, the governor of Louisiana sets the execution date for two weeks after Easter. As news of Jefferson’s impending death spreads through the town, more and more people begin to visit him. Young children and old men, strangers and friends, all come to -Jefferson’s cell to speak to him. The onslaught of attention makes Jefferson begin to understand the enormity of the task that Grant has given him. He realizes that he has become much more than an ordinary man and that his death will represent much more than an ordinary death. Elated by Jefferson’s progress, Grant nevertheless dreads the execution day, when that progress will be tested.
Grant cannot bring himself to attend the execution, for he has grown very close to Jefferson. At the time the execution is scheduled to take place, he orders his students to kneel by their desks in honor of Jefferson. He steps outside the classroom, distressed and bewildered. He knows he should have attended the execution. A few minutes later, a deputy comes down from the courthouse and informs Grant that the execution is over. He assures Grant that Jefferson was the bravest man in the room that morning. Grant looks out over the town, numb and heavyhearted, and discovers that he is crying.