Hello, Stranger, published in 2023, is the 10th novel by New York Times bestselling author Katherine Center. The novel’s protagonist, Sadie Montgomery, is a talented portrait artist on the verge of her big break when an unexpected brain surgery leaves her with prosopagnosia, or face blindness. Suddenly, she can no longer recognize the faces of her loved ones or even her reflection. As she struggles to live and work with her new reality, Sadie is torn between two men: a handsome veterinarian and a mysterious neighbor. Through her struggles, Sadie learns that love isn’t about appearances but about genuinely seeing someone for who they are. Center’s novels have earned her numerous accolades, including the Goodreads Choice Award for Best Romance for Things You Save in a Fire in 2019 and The Bodyguard in 2022. The Rom-Commers is a 2024 New York Times bestseller. In 2020, Netflix adapted The Lost Husband into a film starring Josh Duhamel and Leslie Bibb, and the film was in the top 25 of the year. Netflix released its adaptation of Happiness for Beginners in 2023. Katherine holds an MFA from the University of Houston, and when she's not writing, she enjoys spending time with her family in her hometown of Houston, Texas.

The source material comes from the 2023 St. Martin’s eBook edition.

Content Warning: The source material references medical conditions and surgery, the loss of a parent, and mental health.

Plot Summary

Sadie Montgomery is a portrait artist who earns a meager living by selling her work on Etsy. Sadie quit medical school to pursue art, and since then, she has been trying to prove to her family and herself that she can survive and thrive by pursuing her passion. Sadie qualifies as a contestant in the North American Portrait Society Contest, the same contest her mother was preparing for when she suddenly died when Sadie was 14. Sadie jumps at the chance for the prize money and an opportunity to expose her work to a larger audience. Sadie’s loft apartment is on the top of a building her best friend Sue’s parents own. Sue plans an impromptu celebration party for Sadie. Sadie walks to the store to purchase supplies but forgets her wallet. A handsome stranger offers to buy her groceries, but Sadie refuses. He buys them for her anyway and adds a bouquet. Sadie crosses the street but remembers nothing afterward. She awakens in the hospital and learns she had a seizure, and a “Good Samaritan” pushed her out of the traffic just before she was hit. The doctor diagnoses Sadie with a cavernoma, which requires surgery to correct. Sadie refuses since she can’t disrupt her contest prep. However, her father reveals that her mother died from the same condition and forces Sadie to have the surgery.

Sadie’s doctor diagnoses her with prosopagnosia, or face blindness, which spells disaster for her portrait work. Sadie meets regularly with her neuropsychologist, Dr. Nicole, who helps her unpack the realities of her condition. Still, Sadie quickly becomes overwhelmed with day-to-day life as everyday social interactions are awkward. To make matters worse, Sadie’s evil stepsister, Parker, moves into her building, and Sadie’s beloved dog, Peanut, becomes ill. In the elevator, Sadie overhears a guy in a bowling jacket recounting a one-night stand. His jacket reads “Joe,” so she begins to refer to him as Joe, or the “Weasel,” and sees him coming in and out of multiple apartments, assuming he is sleeping around.

Sadie takes Peanut to the vet, and though she can’t see his face, she immediately falls for Dr. Oliver Addison with his slick-backed hair and sexy lab coat. Fantasizing about marrying this dream guy temporarily takes Sadie’s mind off her problems. After a stay at the vet and treatment, Peanut returns home, and Dr. Addison asks Sadie out on a date. She wants to stay focused on the contest but agrees to meet him for coffee. Yet, when the day of the coffee date arrives, Joe doesn’t show up. Sadie has a run-in with Parker, ending in her spilling coffee on an innocent bystander. Sadie gives the lady her dress, and soon Joe shows up, offering support. Sadie soon learns that Joe’s nickname in the apartment building is “Helpful,” as he is always willing to serve others.

Sue throws a surprise party for Sadie since the first one never happened, but the entire scene overwhelms Sadie, and she has a panic attack. Joe is at the party, and he comforts her. They soon begin spending more time together, and Sadie realizes he’s not the jerk she misjudged him to be in the elevator. Sue serves as Sadie’s model for the portrait, but despite trying several new techniques, Sadie can’t get the face right. Sue and her boyfriend, Witt, decide to elope and leave for a cross-country Canadian trip. Joe offers to be Sadie’s model, and they spend hours together as Sadie maps his face with her hands. They kiss passionately but are interrupted by Sadie’s stepmother, Lucinda, who has come to demand Sadie allow her and her father to attend the art show. However, Sadie only wants one person there, and Joe agrees to be her date.

At Peanut’s follow-up appointment with Dr. Addison, Sadie calls off their relationship because she loves someone else. He is shocked and appears hurt but wishes her well. Meanwhile, Sadie falls for Joe, but he ignores her and doesn’t respond to her texts. She confronts him, and he tells her to stop contacting him. Sadie finishes the painting and attends the art show alone. Parker attends only to torture Sadie, but Sadie stands up to her. When her father and Lucinda arrive, Sadie forces them to see how Parker abuses her and how they have ignored it since she was in high school. Augusta Ross shows up and reveals she was the girl in the coffee shop. She confirms that Parker bullied her in school and blamed it on Sadie. Sadie’s father apologizes for failing her as a dad since her mother died. Sadie loses the contest but is proud of her work and perseveres through a difficult season.

Sue and Witt return, and her parents host a party celebrating their elopement. Though she’s slowly regaining the ability to see faces, Sadie decides to be honest with people about her condition. She leaves Joe a vulnerable, honest voicemail explaining her condition. Joe attends the party, and Sadie learns he is Dr. Addison, the “Good Samaritan” who saved her life. They fall headlong into love and get engaged. An art dealer who saw Sadie’s painting at the show offers her a job, and her paintings sell for thousands of dollars.