The Underground Railroad covers five primary periods in the life of Cora:
1. Life in Georgia
When Cora’s mother, Mabel, runs away, Cora becomes a young outcast among the slaves of the Randall plantation. She fiercely defends the tiny plot of land she has inherited from her mother (who inherited it from Cora’s grandmother, Ajarry) when other slaves try to take it from her, even destroying a doghouse that someone builds on it. When a young slave named Chester is beaten by plantation owner Terrance Randall, Cora intervenes and is beaten. Her fellow slave Caesar, recognizing her independent spirit, asks her to run away with him. Although she refuses at first, she accepts his invitation a few weeks later.
The two run away in the middle of the night and are unexpectedly joined by a young girl named Lovey. They are nearly caught by a group of white hog hunters; Lovey is captured, and Cora kills a white boy in order to escape. Cora and Caesar reach the house of Mr. Fletcher, Caesar’s contact with the underground railroad. Fletcher drives them in his cart, covered by a blanket, to the home of the station agent, Lumbly. Beneath Lumbly’s house, they find a tunnel with a railroad track, and a locomotive carries them north.
2. Life in South Carolina
The locomotive lets Cora and Caesar off in South Carolina, beneath the home of a station agent named Sam, who is a bartender. They are given forged papers with false identities so that they can safely live in South Carolina until another train arrives to take them farther north. However, Cora enjoys South Carolina so much that she is reluctant to leave, and she and Caesar let three trains come and go without boarding them. Cora works first as a maid, then as an “actor” in a museum display teaching white people about slavery. Cora lives in a dormitory with other young black women. After her doctor encourages her to be medically sterilized, she realizes that some of the women she lives with are being sterilized against their will as part of a eugenics project to reduce the black population.
Ridgeway, a slave catcher who has been chasing Cora and Caesar, discovers the dormitory where Cora lives. Unable to find Caesar, Cora goes to Sam, who advises her to hide in the railroad station underneath his house. Cora waits there, but neither Sam nor Caesar joins her. Cora hears a commotion above her and realizes a mob has set Sam’s house on fire.
3. Life in North Carolina
After spending days trapped in the station under Sam’s house, Cora is rescued by an engine passing by. The conductor tells her that he isn’t supposed to be carrying passengers, and he leaves her at what appears to be an abandoned station in North Carolina. A station agent named Martin finally arrives. Cora shouldn’t have come, Martin says, because North Carolina is growing increasingly hostile toward runaway slaves and those who harbor them. Still, he has no choice but to take her with him and hide her in a tiny room above his attic—much to the dismay of his wife, Ethel.
Cora stays hidden for months, watching through an attic window each Friday as the town holds a festival to execute captured runaways. Eventually Cora becomes feverish; Martin and Ethel give their maid, Fiona, a week off so that they can bring Cora downstairs and nurse her back to health. Ethel, who once dreamed of being a missionary in Africa, seizes the opportunity to read to Cora from the Bible. Fiona becomes suspicious and alerts the authorities, who search the house during a weekly festival and capture Cora. As Cora is carried off by Ridgeway, she sees Martin and Ethel being stoned to death.
4. Journey through Tennessee
Instead of taking Cora directly back to Georgia, Ridgeway and his cronies (Homer and Boseman) bring her through Tennessee on their way to capture another fugitive slave. Many of the towns they pass through have been ravaged by natural disasters. They pick up a slave named Jasper and travel with him briefly, but Ridgeway gets irritated by Jasper’s constant singing and shoots him in the face. Ridgeway enjoys talking to Cora, especially to tell her the gruesome fates of Lovey (who was executed by Terrance Randall) and Caesar (who was ripped to pieces by an angry South Carolina mob).
In one town where they stop, Cora makes eye contact with a young black man named Royal. That night, Boseman undoes Cora’s chains in order to rape her. Ridgeway catches him in the act and knocks him down. While the two are fighting and away from their weapons, Royal and two of his companions rescue Cora. They shoot Boseman and overpower Ridgeway and Homer, chaining them to their own wagon. They take Cora to an underground railroad station and travel with her to Indiana.
5. Life in Indiana and Beyond
Cora starts a new life on the Valentine farm, a community of free black people and former slaves. Although most fugitives only stay at Valentine temporarily, Cora is reluctant to leave, just as she was reluctant to leave South Carolina. She falls in love with Royal, who offers to take her to Canada, but she delays giving him an answer. While he is courting her, he takes her to an abandoned underground railroad station with a small track only big enough for a handcar. He doesn’t know where the track leads.
Tension rises in the Valentine community over whether or not fugitive slaves should be allowed to remain there. A legally freed slave named Mingo argues that protecting fugitives puts them all in danger by angering white people. While the issue is being debated, a group of whites raids the farm, killing Royal and a number of others. Cora is captured by Ridgeway and Homer. She leads them to the abandoned underground railroad station, where she escapes by throwing both herself and Ridgeway down the stairs leading to the track. She follows the track until it ends in a cave. A passing wagon offers her a ride: The driver is going to Missouri and then traveling to California. Cora accepts the ride.