Separated from Brown's army, Onion and fellow slave Bob leave the fight in Kansas only to cross paths with pro-slavery "red shirts" who escort them to the slave-trading town of Pikesville, Missouri. Onion is taken under the wing of Pie, a mixed-race prostitute working out of the local hotel, who instructs him in the ways of the world despite her discovering his dangerous secret. Onion soon finds himself enmeshed in a mounting slave insurrection where he learns the consequences of his own actions.

Following the battle in Pikesville, John Brown, now one of the most wanted men in America, travels north with Onion to raise funds for the abolitionist cause. They take refuge at the home of famed orator and "King of the Negroes" Frederick Douglass and his two wives. When Brown and Douglass clash over methodology, Onion discovers just how complex the fight for justice and human equality really is.

John and Onion continue their fundraising mission, this time heading to Canada on foot. After seeing true freedom for the first time and frustrated with Brown's increasingly irrational behavior, Onion demands freedom from Brown's army. But, when the legendary Harriet Tubman endorses Brown in a room full of new recruits, Onion realizes that he may be more invested in the cause and the "old man" than he thought.