Ella searches for an address book, wishing she had contact details for Pru from Sally’s book group. She looks out the window and suddenly sees Sally chatting with Nathan on the front steps. Relieved but annoyed, she goes outside and confronts them. Sally explains that she went to a doctor’s appointment and kept her phone on silent. Nathan says that he also uses phone alarms as a tool to help with his attention-deficit/hyperactivity disorder (ADHD). Ella feels taken aback by the casual oversharing and the reveal that Sally gave Nathan a spare key to her house. When Nathan offers to return it, sensing her distrust, Ella tells him that he looks like Adam Ant. Nathan and Sally laugh, reminiscing about the musician, and Ella recalls a time when her mother was fun and musical.

Sally invites Nathan over for lunch, but he declines, and Ella suspects that her presence is the reason. Inside, Sally explains that Nathan sits outside because he’s lonely. Ella feels sympathy, imagining Willow lonely at college. Over lunch, Ella questions Sally about the appointment, but Sally remains evasive. An Amazon delivery arrives with waterproof sleeves for Sally’s casts. Sally is thrilled at the prospect of a proper shower and asks Ella to help her undress, avoiding further questions about the doctor.

While Sally showers, Ella sees her handbag in the hall. Feeling that Sally is hiding something, she takes it to the sitting room. Hadron the cat stares at her, making her feel judged. Justifying her actions as necessary concern for her mother’s health, Ella opens the bag and finds the TV remote inside. She digs deeper and uncovers Sally’s phone in the inside pocket. The phone requires a passcode, which Ella discovers is her birthday. She opens the calendar and sees today’s doctor’s appointment. Scrolling back, she finds a mysterious entry two weeks ago that simply says “clinic” with no other details.

Ella tries to open the National Health Service (NHS) app but cannot access it. When she opens Sally’s photos, she sees that every single image is one that Ella sent of Willow via WhatsApp. Tears fill her eyes as she realizes that her mother saved them all, indicating that Sally was not as resigned to their distant relationship as Ella had assumed. Continuing to scroll, she finds photos of the undamaged library room with its beautiful floral wallpaper and intact bookcase. Seeing the books as they were, Ella feels a new curiosity about the inscriptions hidden within their pages.

Two men deliver a dehumidifier for the moldy library. Feeling suffocated, Ella persuades Sally to walk to West Greenwich Library. On the way, Sally seems confused and disoriented. She starts walking in the wrong direction before Ella leads her back the right way. At the beautiful red-brick library, Sally identifies the black plaque on the balcony as a cartouche, showing a flash of her old intellect despite her confusion. Inside, they admire the domed ceiling. Mina, a woman in a pink hijab who runs baby sign-language classes, greets Sally warmly in sign language. Ella learns that Sally helps Mina teach the classes and is amazed at this revelation about her mother’s life. Pru arrives and intimidates Mina away. Jakub, another librarian, greets Sally effusively and is devastated to hear about the ruined library, calling it Sally’s life’s work. Sally sobs that it is ruined and that she can’t even picture what it used to be like anymore. Jakub reminds Sally that she photographed the library on her phone to show him. When Sally pulls up the photos, Ella pretends that it’s her first time seeing them. They study the bookcase image together, and Jakub offers to print it for them so that they can remember what was lost.

Twenty years prior, at midnight on Ella’s birthday, Sally enters the newly decorated library room. When Ella moved to Australia, she left behind the 21 books that Sally had given her for each birthday, and Sally hopes that she will one day return and understand the love that built this library. She opens The Catcher in the Rye by J. D. Salinger, the book she chose for Ella’s 21st birthday, and reads the inscription. It references a quote from the novel about things being only partly true and expresses Sally’s deep sorrow and her desperate wish to tell Ella the parts of the story she doesn’t know. The inscription ends with a hope that they can sit in this library and read together again.

Back in the present, Verity arrives at the house with tulips for Sally, and Hadron the cat is friendly toward her. Sally warmly recalls teaching Verity in primary school and encourages the women to enjoy their night out. At The Gypsy Moth pub, Ella marvels at the local sights she once took for granted. Over cider in the beer garden, Verity admits that she’s unhappy in her marriage to her husband, who is always on his PlayStation or out with friends. Ella reflects that her husband, Charlie, is attentive, and feels an unexpected longing for him. She encourages Verity to take an art class at the library to meet new people. She confides that she and Sally grew apart after her father died, recalling how she sided with her demanding father over her nurturing mother during A-levels. Verity confesses that she used to wish Sally were her mother because Sally was so calm and kind. She theorizes that Ella is stuck in a teenage phase of finding fault with parents because she left home at 18 and never returned. Later, woozy from wine, Ella calls Charlie. He tells her that Willow has fallen out with her friend Harper. Ella spontaneously says “love you” at the end of the call for the first time in ages.

Hungover the next morning, Ella studies the library photo while emptying the dehumidifier tank. She identifies The Catcher in the Rye on the shelf and invites Sally to the market, but Sally declines due to rain. While walking alone through Greenwich in Sally’s too-small raincoat, Ella experiences a profound sense of homecoming. The historic atmosphere makes her feel like she belongs. In the covered market, she buys a bangle for Willow and then finds the secondhand-book stall.

Hannah, the stall owner, recognizes Ella immediately and asks after Sally. She reveals that Sally helped run the stall when Hannah’s daughter was having her first baby, allowing Hannah to be present for those precious weeks. Hannah also mentions that Sally shows her all the photos of Willow. Guilt overwhelms Ella as she realizes that Sally enabled Hannah to be with her grandchild after Ella rejected Sally’s offer to come to Australia for Willow’s birth. She also acknowledges that she hasn’t shown gratitude to Charlie for all he does. Feeling overwhelmed, she offers to get coffee for Hannah, needing a moment alone to process how she denied her mother time with her only grandchild.

Hannah gives Ella a copy of The Catcher in the Rye in exchange for coffee. While walking toward the library, past conversations with her mother replay in Ella’s mind, and she realizes that she’s invented a narrative where Sally did good deeds as penance. Now, she sees that Sally is simply kind and always has been. At the library, she studies watercolor paintings, finding them calming. Jakub approaches and expresses concern that Sally seems diminished, like a dimmer switch turned down. Ella agrees that Sally seems different, and they speculate that it could be depression. Jakub says that having Ella there is the tonic Sally needs. Ella admits that she feels like she’s getting to know her mother again.

Jakub reveals that Sally came up with the name for his drag act, “Bridget Bard-Oh,” a play on Shakespeare and Brigitte Bardot. He says that Sally and her neighbor Glenda attended his first performance. Jakub theorizes that children prefer to see parents as infallible saviors rather than complex humans and that acknowledging parental fallibility rocks one’s worldview. Ella has an epiphany: She learned of her mother’s fallibility on the day of her father’s funeral and has been unable to trust anyone fully since. She resolves that it is time to accept that her mother is human.

Home again, Ella teases Sally about Bridget Bard-Oh. Sally explains that she tricked Glenda into attending by comparing it to Morecambe and Wise. In the basement kitchen, Ella discovers steam, a sulfurous smell, and a pan with an exploded egg that has nearly boiled dry. Alarmed, she scolds Sally for the dangerous mistake. Sally apologizes, saying that she forgot. Ella shows her the copy of The Catcher in the Rye that Hannah gifted her. Sally recalls the book’s themes and explains that she bought it for Ella’s 21st birthday, the year Ella left for Australia, because she knew that Ella saw her as the enemy and wanted to explain what really happened. Ella confronts her about having an affair with a man named Andrew before Ella’s father’s death. Sally forcefully states that there was no affair. She explains that she, Neil, and Andrew were close friends in college. She and Andrew exchanged letters secretly because Neil held a grudge against Andrew, but it was never more than friendship.

Ella challenges Sally, asking how she would feel if Charlie had a secret emotional relationship with another woman. Sally admits that she understands why Ella was hurt but clarifies that Neil never knew about the letters and didn’t die thinking she had betrayed him. Ella realizes that the turmoil she felt was based on a misunderstanding. Sally swears that after Ella found the letter from Andrew on the day of Ella’s father’s funeral, Sally never contacted Andrew again. Looking into her mother’s eyes, Ella believes her. The weight of 21 years of resentment lifts.

Two builders arrive to give Ella a quote for repairs. She dislikes their patronizing attitude and performative bluster. They try to intimidate Ella by warning her about cowboys, but Ella confidently dismisses them. Hadron growls at the men. After they leave, Sally suggests asking Glenda for a builder recommendation. Ella reminds her that Glenda is in Antibes, and Sally seems confused. Ella’s concern deepens, and she suggests a memory clinic visit. Sally looks at her sling as if seeing it for the first time. Ella suggests stopping the painkillers. To lift Sally’s mood, she proposes getting copies of F. Scott Fitzgerald’s The Great Gatsby so that they can read it together. At the market, Hannah greets them warmly. While Ella gets coffee, Sally and Hannah chat and laugh. Ella is filled with affection upon seeing her mother happy. Hannah mentions that Sally couldn’t remember which book they were looking for. Sally, who was previously evasive about her doctor’s visit, now insists that the doctor said she was perfectly fine. She claims that she discussed her memory issues with the doctor, who said there was nothing to worry about. Ella is skeptical but drops the subject. Hannah refuses payment for the book and says that everyone deserves a library made specially for them. Inspired, Ella decides to rebuild the library that her mother made for her and also to create a new special library for Sally in return.

When they stop by the library, Jakub greets them warmly. While he and Sally chat, Ella browses for another copy of The Great Gatsby. She regrets having rejected her love of reading just because it was something Sally encouraged. She finds her book and rejoins them. Jakub suggests that Ella get her own library card. The reminder that she has only two weeks left of her visit makes her unexpectedly sad. She asks about art classes for Verity. Sally notices Malcolm, an unkempt man muttering about Jesus, and greets him warmly. As Sally sits to talk with Malcom, Jakub tells Ella that Sally is a superstar whom everyone loves, explaining that Malcolm likely hasn’t spoken to anyone else all day. He says that Sally is the only person who doesn’t bow and scrape to the difficult Pru, which is likely why Pru is extra frosty with her.

Ella sends Verity the art-class details, receiving excited emojis in reply. She asks Jakub to help with a project: creating a library for Sally with books chosen by people whose lives she has touched, each with an inscription inside. Jakub is overjoyed and agrees enthusiastically. As Ella is about to join Sally and Malcolm, she sees a young man in a hoodie furtively grab a can from the food-bank donation cage and shove it in his pocket. As he hurries out, he glances back and catches her eye. Ella realizes that it’s Nathan.

That evening, Ella and Sally read The Great Gatsby. A line from the book makes Ella think about purpose and the ways that her relationship with Charlie has improved as she’s made an effort to be vulnerable. She asks Sally why she chose this book for the library. Sally explains that she bought it when Ella got a promotion because she was worried that Ella was becoming materialistic. She points out that Ella’s email celebrated her success without mentioning the people who lost their jobs in the corporate restructure. Ella feels defensive, but Sally says she worried that her affluent Greenwich upbringing and her father’s materialism had skewed Ella’s values.

As an example, Sally mentions Ella’s negative judgment of Nathan. Ella retorts that she was right because Nathan is a thief. She tells Sally that she saw him stealing from the food bank. Instead of condemnation, Sally expresses compassion for the young man. Ella’s indignation dissolves as she realizes that Nathan took the can because he was hungry. Sally is tearful, saying that she told him to come to her for help. Ella realizes that her own coldness must have kept him from reaching out. She apologizes for lacking empathy and offers to buy groceries for Nathan. While walking to the shop, she reflects on her privileged life, including nepotistic summer jobs at her father’s law firm. She acknowledges that her mother was right about her values. At the mini market, she buys staples and treats for Nathan, feeling lighter with the hope of making amends.