In a quiet London neighborhood, a cantankerous and enigmatic homeless woman named Miss Shepherd takes up residence in a decrepit van parked on the driveway of playwright Alan Bennett’s home. Initially intended as a temporary arrangement, Miss Shepherd's stay extends to an unexpected fifteen years. Throughout this period, Bennett forms a complex relationship with her, characterized by a mix of irritation, curiosity, and compassion. As he navigates his own personal struggles, including the care of his aging mother and the pressure to continue his writing, Bennett becomes increasingly entangled in Miss Shepherd's mysterious past.

Gradually, Bennett discovers fragmented details about Miss Shepherd's earlier life, including her aspirations as a concert pianist and the series of unfortunate events that led her to homelessness. Despite her abrasive demeanor and fierce independence, Miss Shepherd's vulnerability is unmasked little by little through their interactions. With each revelation, Bennett’s curiosity deepens, challenging his own perceptions of charity, kindness, and responsibility. Before long, her presence becomes a peculiar yet integral part of his life, reshaping his understanding of what it means to offer help and share humanity with a stranger.