Edward "Ted" Wallace is a disillusioned writer and former poet, now in the twilight of his life. After a long creative drought that has lasted since 1987, he finds himself reduced to critiquing trivial stage productions, spending his days wallowing in a bath and indulging in excessive drinking. His life takes an unexpected turn when he loses his job due to heckling a lackluster performance. This misfortune leads him to cross paths with his goddaughter Jane, who offers him a generous payment to uncover the mystery behind a series of miracles that seem to have coincided with her surprising recovery from leukaemia.
Ted's investigation leads him to a lavish manor owned by his old friend, Michael, Lord Logan. There, he meets his sixteen-year-old godson, David, an inquisitive boy with a peculiar interest in both sex and nature. Alongside him are David's brother Simon, their aging friend Oliver who is troubled by angina and is searching for funding for his theatrical ambitions, an awkward Frenchwoman named Clara Richmond, and her affluent mother Valerie, who has her sights set on acquiring a horse named Lilac from the estate for her daughter.
As Ted settles into life at the manor, his cynical demeanor clashes with the upbeat attitudes of the others, thereby creating a palpable tension. Throughout this turbulent stay, he engages in conversations with David, who expresses lofty ambitions of becoming a poet himself, weaving together aspirations of creativity and self-exploration.
Strange occurrences begin when Lilac, the horse, apparently falls gravely ill from ragwort poisoning, although the plant is not native to the region. In the midst of the group's anguish over the potential euthanasia of Lilac, Ted uncovers the truth behind the miracles he was sent to investigate. It appears that David, through his astonishing abilities, has healed his mother's acute asthma attack with just a touch, and later, he miraculously cures Jane's cancer in a similar fashion over several days.
As the days progress, David performs further feats, restoring Lilac’s health and alleviating Oliver's heart condition, garnering Valerie's interest in hopes of enhancing Clara's appearance by association. However, as David and Clara venture into the woods for a secret meeting, a frantic search ensues when they go missing. Ted finds Clara in a compromising position with David, leading to unforeseen chaos. After a confrontation that results in Clara biting David, Ted navigates the complicated emotions of their predicament, ultimately driving a wounded David to the hospital.
David's belief that his healing gifts stem from moral purity and a spiritual bond with nature is dismissed by Ted as mere fantasy, leading to a rift between the two and leaving David heartbroken. Meanwhile, Ted faces harsh criticism from Rebecca, Michael's sister, who harbors resentment towards him for a past humiliation. This culminates in a ruinous night filled with self-pity for Ted, as he confesses that Lilac’s poisoning was merely a hangover from his neglect.
When the truth finally surfaces, exposing the actual causes of the supposed miracles, the manor's residents are outraged, particularly at the implications of David's misguided confidence in his powers, culminating in a grim revelation when Jane's leukaemia returns. The narrative takes a poignant pause, allowing time to pass as life resumes at the manor, yet the echoes of that summer linger.
At Jane's funeral, a now matured David reflects on his journey and the hard work that comprises his new life. In a cathartic moment, Ted finds solace and inspiration from his experiences during that transformative summer, emerging from his creative slumber with five new poems to his name. With renewed hope and reflection, he raises a glass in solitude, proclaiming a toast "to miracles," marking the resurgence of his artistic spirit against the backdrop of life's harsh realities.
