The story opens with Ford Grant Jr., a newly minted billionaire and music industry entrepreneur, working to renovate a dilapidated barn on his property near Rose Hill, a small Canadian mountain town. His best friend Weston Belmont teases him about being named Forbes' "World's Hottest Billionaire," a title Ford loathes. Ford explains his plan to launch Rose Hill Records, a recording studio and production company, having already produced one successful album. He values Rose Hill for its privacy and simplicity, far from the media spotlight he despises. A knock at the door interrupts them, and Ford opens it to find Cora Holland, a twelve-year-old girl dressed all in black who announces she is his biological daughter—the result of a sperm donation Ford made at nineteen for concert ticket money. She presents DNA evidence from Kindred, a genealogy service Ford himself had used. After initial shock, Ford learns Cora's father Doug died of ALS, her mother Marilyn is severely depressed, and Cora has no other family. Ford drives Cora to Calgary, meets Marilyn, and agrees to help.

Meanwhile, Rosalie "Rosie" Belmont, West's younger sister, is living in Vancouver with her boyfriend Ryan. After delivering an excellent presentation at her corporate job, her boss Stan sexually assaults her by grabbing her. Rosie confronts Stan and vows to report him to HR, but HR is gone for the day. When she tells Ryan, he dismissively advises her to ignore it to protect her career. The next morning at work, HR intercepts Rosie—and she realizes she's about to be fired. Devastated and directionless, Rosie breaks down.

Two weeks later, Rosie returns to Rose Hill, arriving at West's farmhouse. She's stunned to find Ford at the door. Their old dynamic of bickering and teasing resurfaces immediately, though Rosie is hiding deep pain. Ford notices her watery eyes but doesn't press. West asks no questions and gives her the bunkhouse. Over the following days, Ford officially becomes Cora's kinship placement guardian. He struggles with parenting basics—snacks, bedding, conversation—while also failing to tell his own parents about Cora. Rosie pitches herself as Ford's assistant; he hires her on the spot as his business manager instead, recognizing her MBA and business acumen.

Ford and Rosie settle into a charged working dynamic, sitting at desks facing each other in the dusty barn office. Ford reveals he retrieved Rosie's diary years ago after she threw it from a car window as a heartbroken teenager—he searched multiple times but never read it. Rosie is deeply moved. She picks up Cora from school daily, bonding with the girl over shared snark and emotional understanding. Rosie also reconnects with her friend Tabitha, who runs the local bistro and is overwhelmed caring for her sister's toddler.

Tensions between Ford and Rosie escalate. During an evening by the lake, they share chips and banter on the dock, but a playful chip fight turns physical—Rosie's hand lands on Ford's bare chest, and the mood shifts dramatically before West interrupts and Rosie shoves Ford into the water. Later, around a campfire Ford builds with Cora and Rosie, their connection deepens further. Ford asks if Rosie is single; she says she doesn't know. He tells her to figure it out before asking again, then walks away. Rosie texts Ryan trying to arrange a talk, but he schedules a visit a month out, showing little urgency. Rosie reads her old diary entries about Ford late into the night.

Ford agrees to join a local bowling team to secure a trusted contractor, Sebastian Rousseau, for the office renovation. Rosie offers to babysit Cora. Ford shares a torn-out diary page Rosie left him—her teenage account of the night he picked her up after her breakup—and reveals he broke every speed limit to reach her that night. He also awkwardly attempts to set professional boundaries, telling Rosie he'd only call her "Rosie" if they were going to sleep together, which offends her. Their dynamic settles into a pattern of charged emails, mutual attraction, sharp banter, and unresolved tension.