One day, while building a structure on Epps' property, Solomon meets Bass, a hired hand from the North. Epps offers Bass some liquor, but Bass declines, before telling Epps that he thinks the working conditions for the slaves are deplorable. Bass openly opposes slavery, saying, "What right have you to your niggers, when you come down to point?" He suggests that universal truths are constant, while laws might change, and supposes a world in which Epps is made a slave.
Epps is not convinced, suggesting that comparing white and black men is like comparing a white man and a baboon. Bass suggests that there will be a day of reckoning, which angers Epps, who suggests his ideas would go over better in New England.
Later, Epps comes running out of the house calling for Patsey. None of the other slaves know where she is, and Epps mourns the loss. When Patsey returns later, Epps attacks her and accuses her of having a sexual relationship with Shaw. Patsey pulls out a bar of soap that Mistress Shaw gave her, saying that Mrs. Epps won't give her any. "I stink so much I make myself gag!" she cries. When Epps doesn't believe her, Patsey insists that she is not a liar.
As Mistress Epps comes out of the house, Epps has Patsey stripped and tied to a tree, so he can whip her. "You've done this to yourself," Epps says, before going to whip her. At the last moment, he hands Solomon the whip and orders him to do it. "I'd rather it you, Platt," Patsey calls, and Solomon picks up the whip and strikes her. As he does so, Mistress Epps and Epps encourage him to strike her harder. When he does not strike her hard enough, Epps holds a gun to Solomon's face and says that if he does not hurt Patsey more, "I will kill every nigger in my sight."
Solomon whips Patsey harder and harder, then stops. Epps picks up the whip himself and takes over whipping Patsey. When Epps is done, Solomon unties Patsey, whose soap has fallen onto the ground in front of the tree. Later, the slave women tend Patsey's horrible wounds.
That night, Solomon destroys his violin in the forest. Afterward, while building with Bass, Solomon asks Bass where he's from. Bass tells him he's from Canada, and is surprised to hear that Solomon has been to Canada himself. He then tells Bass that he does not belong on the plantation. When Bass asks to hear his story, Solomon is afraid to tell him, but Bass assures him that he will keep his secret.
After telling his story, Solomon asks Bass to write to his friends in the North and ask for free papers. "It would be an unspeakable happiness to see my wife and my family again," he says, weeping. Bass says he is afraid, but will write the letter, as they get back to work.
While Solomon is working in a field one day, a carriage pulls up and a sheriff calls to him. Solomon goes to the carriage, where his friend, Mr. Parker, from Saratoga, is waiting. The sheriff asks Solomon about his identity, and he answers correctly, as Epps comes out of the house to see what is going on. As Solomon runs to Parker and hugs him, the sheriff is convinced, and releases him from Epps' custody.
As Solomon goes to the carriage, he spots Patsey and the two embrace. He gets in the carriage and waves goodbye, as Patsey sobs.
Solomon returns to his home in Saratoga, where his family has aged. "I apologize for my appearance, but I have had a difficult time these past several years," he says to them, weeping. He meets his daughter and his daughter's husband, and then his grandson, who is named after him. His family goes to him and hugs him.
A titlecard tells us that "Solomon Northup was one of the few victims of kidnapping to regain freedom from slavery." We also learn that he lost his trial against his abductors, but became an abolitionist in the years following, helping other slaves gain their freedom. In 1853 he published the book Twelve Years a Slave.
In this final section of the film, Solomon meets Bass, a man from the North who vehemently opposes slavery. Bass is a white Canadian who, as such, has a certain ability to talk to the cantankerous Epps, and appeal to his philosophical beliefs about the institution of slavery. In their conversation, Bass imagines a world in which a law is passed that makes Epps a slave, suggesting that there is a universal moral system that dictates that slavery is wrong. This is the first time we have heard a character who is structurally able to do so speak openly and critically about slavery.
The horrors of racism and slavery are often intermingled with sexual possessiveness and jealousy, particularly in the relationship between Epps and Patsey. The complexity of Epps' feelings towards Patsey—at once deeply bigoted as well as tender and longing—is what makes them so evil and violent. In the midst of physically attacking her for having left the plantation, he also accuses her of having a sexual relationship with Shaw; these two betrayals are aligned in Epps' mind. Thus, we see that a major vector for the violence and ruthless logic of slavery is not only ownership in a literal sense, but in a sexual sense as well.
The slaves in the film are figures through which their white masters can enact their own shame and inner demons. Not only is Patsey a complicated object of desire for the abusive Epps, but he even forces Solomon to whip her when the moment comes to dole out her punishment. Epps' great violence is that he creates a violent home and then forces those under him to commit the worst brutalities, freeing himself from the consequences of his own destructive impulses. As Epps hands Solomon the whip, forcing him to hurt the vulnerable Patsey, the viewer sees that the violence of slavery is not simply the violence itself, but the ways that that violence spreads outwards, gets outsourced to others, and poisons the entire moral universe of a plantation.
The scene of Patsey's whipping is viscerally disturbing, a nightmarish sequence of human violence. After Solomon stops whipping Patsey, disheartened by his task, Epps picks up the whip with gusto and strikes Patsey hard. We see the whip come down on her back, as Epps' eyes fill with a maniacal glee. McQueen shoots the scene straightforwardly, showcasing the flagrant evil of Epps, the perverse and horrific righteousness with which he controls the lives of his slaves, and the nightmarish trauma endured by Solomon and his fellow slaves.
While Solomon eventually finds freedom and returns to his former life, the story's ending is not simply a happy one. Solomon is reconvened with his family, but he has missed a great deal, and the horrors of slavery have left him a shell of the man he once was. As the film ends with Solomon embracing his family, the viewer knows that his reintegration into society will be an arduous project, and that his individual redemption is a rare light in the darker story of American slavery. The enduring darkness is symbolized by his rushed and speechless farewell to Patsey, and her sobs as his carriage drives away from the plantation.