In 1980, Hilary Small works diligently as a duty manager at the Empire Cinema in Margate, situated on the picturesque north coast of Kent, England. Battling bipolar disorder, she navigates her life alone, relying on lithium prescribed by her GP, while engaging in a complicated affair with her boss, Donald Ellis.
The atmosphere changes when the charming Stephen, a Black British newcomer, steps into the cinema. Living with his devoted mother, Delia, who works as a nurse, Stephen quickly captivates Hilary's attention. Their bond deepens as she introduces him to the cinema's enchanting but neglected upper floor.
However, with Stephen's growing friendship with a younger employee named Janine, Hilary's jealousy simmers beneath the surface. A spontaneous kiss during a New Year's Eve fireworks display ignites a passionate sexual relationship. In her newfound happiness, Hilary decides to stop her medication and cut ties with Donald.
As the couple grows closer, Hilary witnesses the harsh realities of the world through Stephen's experiences. After seeing him confront skinheads on the streets and dealing with the fallout from a racist customer, she begins to understand the challenges he faces. They enjoy moments at the beach, where Stephen reminisces about his first love, Ruby, who is also a nurse at the same hospital as Delia. When Hilary is pressed to share her past, her emotions spill over, leading to an intense outburst as she destroys their sandcastle.
Their secret romance does not go unnoticed; Neil, a colleague, warns Stephen about the potential dangers of being involved with Hilary, especially concerning her mental health. Meanwhile, the cinema is set to host the regional premiere of Chariots of Fire, and in a fit of manic energy, Hilary delivers a chaotic speech, ultimately revealing her affair with Donald to his unsuspecting wife. This leads to a rapid decline in Hilary’s mental state.
When Stephen checks on her at her flat, the situation escalates dramatically as mental health authorities force their way in, taking Hilary for reevaluation and treatment.
After a few weeks, the cinema returns to normalcy with Donald's departure and Stephen's training with Norman as the projectionist. He even runs into Ruby again, reawakening their romance. Meanwhile, Hilary is discharged from the hospital, and Stephen encourages her to experience a movie at the cinema—something she has never managed to do despite her role.
During her welcome-back party, however, the atmosphere turns menacing when a group of skinheads protest outside, culminating in an assault on Stephen. The movie's events drag Hilary back to the hospital with him, where she is introduced to Stephen's mother.
As Stephen recuperates, Hilary finds it hard to approach him. During this time, Norman shares his own parenting regrets and advises her against running away from her feelings. Realizing her love for Stephen, she visits him at the hospital and hears from his mother how much he cherishes her. Excited, Hilary rushes back to the cinema to have Norman play Being There for her.
When Stephen returns, he expresses his intention to leave town for college, a decision spurred by Hilary’s guidance. At a farewell dinner with Ruby and his mother, Stephen reflects fondly on his time with Hilary. The two later meet in a park, where Hilary gifts Stephen a book, marking a bittersweet farewell.
As Stephen boards his train, he opens the book to find a passage from High Windows by Philip Larkin, capturing a poignant moment of their story—a memory that will linger over both their lives.
