The following version of the book was used to create this study guide: Greenwood, Bryn. The Reckless Oath We Made. Penguin Random House, New York, NY, 2019. Kindle AZW file.

Zhorzha Trego is in her mid-twenties and is struggling to meet her obligations. She helps pay the bills for the apartment she shares with her sister and nephew, LaReigne and Marcus. Additionally, she is still paying medical bills from a motorcycle wreck and often helps with expenses for her semi-invalid mother, Dorothy. Zhorzha, known as Zee, supplements her meager income by running drugs. She is returning home from making a delivery when she learns that LaReigne has apparently been kidnapped by two men who escaped from the prison where LaReigne was a volunteer. When Zee finds her apartment surrounded by police and reporters, she takes Marcus to Dorothy's home where she has to push her way through a throng of reporters. With her hip injury and with Marcus in tow, Zee is struggling when a man named Gentry rushes to her aid.

Gentry Franks is a high-functioning autistic man who communicates by using medieval English and taking on the role of a knight. Months earlier, a voice in his head told him that he was to serve as Zee's champion, and he pledged an oath to that effect. Zee was desperate when they met and accepted him, odd speech and all. She is grateful for his help as she tries to cope with the fallout of LaReigne going missing.

Zee's father, Leroy, was arrested years earlier when he and his brother, Alva, robbed banks and killed a guard. Leroy took the blame for killing the guard though it was Alva who actually shot the man. Alva spent several years in prison, but Leroy died there. The two robbed the bank because they needed money for Alva's wife's medical bills. His wife died, and the money was never recovered. Zee reaches out to Alva, hoping he can help her find out who kidnapped LaReigne. Alva makes some phone calls and finds out where the escapees are staying; then, he hands over almost $100,000 for Zee to use as ransom money. Zee is angry, but Alva reveals that he has been giving Zee's mother money over the years, which she has used only to increase the number of items she hoards in her house.

Gentry accompanies Zee to Alva's and then makes the plan to go to Arkansas where they believe Zee is being held. Gentry calls on two of his friends – Edrard and Rhys – who are his closest friends and who participate in the medieval lifestyle. Edrard is fully invested, but Rhys refuses to leave the motel. Zee, Gentry, Edrard, and Alva's son Dirk travel to rural south Arkansas where they discover there are four men with LaReigne. The situation is almost immediately out of control because LaReigne is not being held against her will and actually helped the men escape. Edrard is shot in the stomach, Gentry kills a man and wounds another, and Dirk shoots at least one man. They call for help, but Zee knows she has to leave before police arrive or risk losing Marcus. Gentry is torn but refuses to leave Edrard, who later dies. Zee and Dirk get away. No one mentions their presence, even though Gentry goes to jail for manslaughter and LaReigne is jailed for helping the men escape.

Zee takes Dirk home and settles in to find new normal life. She forces Dorothy to clean up her house and gets weekend visitations with Marcus. Gentry's adoptive mother feels that Zee pulled Gentry into a situation he did not understand. Zee understands the anger but continues to stand beside Gentry by using part of her money to make the payments on the land where he is building a castle. As the novel comes to a close, Gentry's mother realizes that Zee is showing her loyalty and begins to welcome her into the family. Zee and Gentry are each coming to terms with the guilt over Edrard's death as they make plans for their new lives.