Lou's past haunts her when her friend Charlotte arrives, followed closely by Wicks a man who hurt them both. After Charlotte mysteriously dies, Lou tells Rachel everything. Hickok tries to help an injured Lakota, Red Sky.
Isaiah Burke and wife Rosemary are abolitionists trying to lead a group to freedom but slave catchers are close behind. Hickok helps them out but also falls in love with Mrs. Burke. Isaiah is captured and must be rescued by the riders.
The Kid helps out Margaret but the act of kindness connects him to a plot to steal a gold shipment. Both sides on the slavery issue want the money to help their cause and are willing to use any means necessary to get it.
Teaspoon falls for Miss Marie who claims to be destitute because of a robbery. But Jesse and Bill learns she has a connection to an outlaw gang. Hickok seeks vengeance outside the law after a child is murdered.
Jesse has a new boss in Walter, a gruff man who is the father figure the lonely boy is looking for. But Jesse finds him murdered right after the return of Tarkoski from prison and the others have to stop an act of revenge.
Buck encounters Camille, about to wed Bill Barlow, who he left behind when they ran across buffalo hunters. She was Little Feather then and when she seems possessed Buck takes her to find a Native American healer to heal her.
Cody has written a story about the riders and the rest take exception about how they are portrayed when it's published. Jimmy and Jesse take after cold blooded killer Dobbins who's after a widow and her son Seth.
Teaspoon and Jimmy save African American Edward from a lynching. It brings their disagreement over the South and slavery to a head. The Kid's proposal to Lou is stopped by a gunfight and a prisoner named Dawkins who's help they need..
Killer Randle is seeking vengeance against Marty who testified against him and Teaspoon is unable to prevent it. His ex-love Polly and a lawman friend also arrive in town. Buck and Cody take off after Randle followed by Teaspoon to get justice.
Jimmy trains a new rider Matt who on an ride meets a terrible end at the hands of the Garrett family. Jimmy finds a town in terror but with Lou's unexpected appearance faces the killers. Lou fears the changes marriage to Kid will bring.
War arrives on the plains forcing the riders to choose sides. Cody joins the Union army while Frank returns for his brother Jesse. But a encounter with renegade Rebels leaves Noah dead and the rest intent on giving him justice.