Hannah Hall, a professional woodturner living in California, receives a short cryptic note from her husband Owen Michaels, telling her to protect his teenage daughter Bailey. The message puzzles Hannah, but she soon learns that Owen has disappeared in the wake of legal raids at The Shop, the tech company where he works. He also leaves a note for Bailey, as well as a duffel bag full of money. Hannah tells no one about the notes or the money, and everyone assumes that Owen fled because he is guilty. The assessment of Owen that emerges from these events diverges from the image of the good and honest man Hannah married. Visits from federal authorities, including a US Marshal named Grady Bradford, confuse and panic her. Meanwhile, at home, Owen’s disappearance exacerbates her tense relationship with Bailey, who is furious at her father for leaving and more distant and dismissive than usual toward Hannah. 

Interspersed with Hannah’s narration about present events are flashbacks to her courtship with Owen. She recalls the sincerity of their connection and how they bonded over her work, as well as more recent memories of their married life. Her recollections of Owen show a man who loves his wife and daughter, although he is sometimes distant and avoids talking about his past and his work. Once Owen disappears, though, these memories take on new meaning, and the two women increasingly scrutinize what they know, or thought they knew, about Owen. Various clues suggest that Austin, Texas, might have played a role in Owen’s mysterious past, and Hannah increasingly believes that whatever he is fleeing from involves Austin rather than the criminal activity at The Shop. She is also convinced he disappeared to protect his daughter, not himself. 

Hannah takes Bailey to Austin in the hopes that they can learn more. Hannah hopes that visiting the city will trigger Bailey’s early memories, giving them additional clues about what happened in the past and what is happening in the present. Once there, however, Hannah and Bailey find it difficult to gather the information they need. What they know seems uncharacteristic of Owen, and Bailey’s memories remain fragmentary. Tensions erupt as Bailey antagonizes both Hannah and the friendly strangers they meet in Austin. She confronts Hannah about lying to her and extracts a promise that they will be honest with each other in the future. The two visit the University of Texas football stadium, and Bailey feels that she has been there before. They both hope the nearby Episcopal church that Bailey recognizes will provide some answers, but Elenor, the church secretary, denies that a wedding could have taken place in 2008 during the timeframe they provide. 

Hannah receives a call from Jake, a New York attorney and her former fiancé, who tells her that Owen Michaels does not exist. The information Owen shared about his background matches no known person, and he only appears in 2009. The women find this news deeply distressing, although Hannah believes that some details of Owen’s previous life exist amidst the fictions he created. His favorite college anecdote leads them to University of Texas professor Tobias Cookman. As Hannah and Bailey work through one of Tobias’s class rosters, Elenor calls to confirm that the wedding Bailey remembers did indeed occur, just earlier than they had assumed. During their research, they stumble on Katherine Smith, a classmate of Owen’s who bears an eerie resemblance to Bailey. They surmise that this woman is Bailey’s mother. 

Hannah and Bailey go to the Never Dry, a bar with a connection to Katherine. Hannah refuses to let Bailey come into the bar until they know more. At the Never Dry, she meets the owner, Charlie, and learns that Katherine is his late sister. When Hannah shows him a picture of Owen, Charlie explodes in rage. Bailey rushes in and, startled, Charlie calls her Kristin. Shaken, the women flee the bar and return to their hotel room. Hannah pieces together that Katherine had been married to Owen, then known as Ethan, and that Bailey, born Kristin, is indeed Katherine’s daughter. She also learns why Ethan became Owen. Criminal associates of Katherine’s father Nicholas, a corrupt attorney, killed her, which led Ethan to provide evidence against Nicholas that helped to send him to prison. Fearing for his daughter’s safety, Ethan changed their identities and moved to California. Hannah realizes Bailey has run away from their hotel room while she was piecing together this information.  

Grady arrives and dispatches agents to find Bailey. While they wait, he tries to convince Hannah that their safety demands that she and Bailey enter witness protection. Hannah rejects his offer, arguing that for Bailey to change her identity now will destroy her given how much she has already lost. After confirming that a piggy bank on which Owen seemed focused contained his real will, Hannah returns to the Never Dry and convinces Charlie to take her to Nicholas at his house outside Austin. During a tense negotiation, Nicholas agrees to allow Hannah and Bailey to live openly in safety—but categorically refuses to extend the same offer to Owen. Hannah and Bailey reunite at the Marshals’ office. Hannah keeps her promise not to lie to Bailey and asks her what she wants to do. Bailey chooses to go home to California with Hannah, knowing that she will not see Owen for a long time. The novel’s ending, set a few years later, reveals that Hannah and Bailey have become very close, conveyed clearly when Bailey calls Hannah “Mom.” Owen is still in hiding, even from his family, but he briefly appears at one of Hannah’s exhibitions, wearing his wedding ring. Hannah is reassured that he is the good man she always believed him to be, but, as she turns to Bailey, the novel shows that her relationship with her daughter is now the most important one in her life.