The following version of this book was used to create the guide: North, Anna, Outlawed, Bloomsbury, 2021.

North's novel is divided into 12 chapters, each corresponding to a different setting, season, or venture. Set in America in the 1890s, the plot follows the unusual story of 17-year-old Ada from the time she is married to the time she settles down as a midwife. In the form of a memoir, Ada recounts how she became an outlaw and the many dangerous adventures she experienced in that role.

Ada's tale begins with an ordinary and happy marriage to a young man she has known most of her life. As she has learned at school, Ada is expected to bear children quickly. The townspeople of Fairchild all view childbearing as a pact made with Baby Jesus to avert early death and disease. All except Ada's mother, the town's midwife, who privately rejects the general population's superstitions linking barrenness to witchcraft. Ada enjoys assisting her mother; while honing her medical skills, she also receives valuable life lessons.

When an entire year goes by without a pregnancy and after Sheriff Branch's visit, Ada's mother knows that she must send her eldest daughter to the convent for fear of punishment. With the sisters of the Holy Child, Ada is safe but lonely. She finds solace in the convent's many science books. Tormented by the question of barrenness that has caused her exile, Ada searches for answers in these books. Some support superstitions; others expose the true causes of barrenness, miscarriage, and stillbirth, and the motivations behind abortion. She learns about a surgery practice in Pagosa Springs that addresses women's ailments, and she decides to travel there.

Riding in secret in a bookseller's wagon, Ada reaches the Hole in the Wall, the camp of a notorious group of outlaws whose leader, the Kid, Mother Superior once helped. The other six - Cassie, Texas, News, Agnes Rose, Lo, and Elzy - mistrust Ada at first but the Kid finds her medical skills valuable and lets her stay. Ada learns to ride horses, shoot, dress, behave, and fight like a man, and even receives lessons in mental toughness. Ada also discovers the gang's mission: that they may one day be able to build a nation for all barren women to inhabit.

At Sutton's Gulch, Ada's first act as an outlaw - the theft of a wagon filled with cash - is a disaster: she causes Elzy to be shot and the driver to be killed. Ada manages to treat Elzy but leaves her handicapped. Eager to redeem herself, Ada travels with Agnes Rose to procure laudanum. The gang wants to steal from a bagman carrying the Fiddleback Ranch's money once he is drugged. Disguised as men and waiting for the man at a bar, Agnes Rose, News, and Ada meet two other thieves, Henry and Lark, who tell them about the Fiddleback bank. Ada feels attracted to Lark but does not betray herself. The three gang members steal the bagman's satchel only to discover a note stating that the Fiddleback bank owns the ranch.

During a harsh winter, the Kid hatches her greatest plan ever: to rob the Fiddleback bank and buy it back with the goal of eventually owning the entire town. Opposed to the plan, Cassie suffers from hypothermia after stalking away. Ada heals Cassie but realizes that the Kid also needs help. In exchange for her discretion about chronic insomnia and her vote in favor of the plan, the Kid promises to let Ada reach Pagosa Springs. In the spring, Ada makes a bomb to blow to open the bank vault. She and Agnes Rose meet up with Henry and Lark in Casper to steal a wagon for the heist. Ada and Lark are apprehended and thrown in jail. They ask to be married so that they may escape but are both wounded.

When they return to the camp, Ada finds that the Kid's condition has worsened. The Kid gives up her gun and goes into isolation. In the Kid's absence, Cassie takes the lead and decides to go on with the plan despite Lo's departure. Ada and Lark become closer and make love. On May 30, 1895, the gang heads to Fiddleback and enters the bank. Lark is killed in a shootout with a bank clerk. Ada and Cassie mourn his death. Holding all the bank's gold, the gang waits to return to Fiddleback the following week. Concerned about the Kid who now sleeps all the time, Ada goes to speak to her and learns that she had to give up a daughter.

On the day of the bank purchase, the gang's encampment is surrounded by sheriffs from neighboring towns. Ada manages to escape one only to find herself trapped by Sheriff Branch. The Kid rescues her by killing Sheriff Branch. The gang fights off the other sheriffs. In the fall, several women show up at the Hole in the Wall after hearing of the gang's exploits. The Kid welcomes them but Ada finds that it is time for her to head out. With News and Texas, Ada reaches the surgery practice in Pagosa Springs but Alice Schaeffer is gone. Undeterred, she decides that it is her duty and mission to take over the practice. The reader learns that she goes on to lead a productive life fulfilling her mission of helping other women.