On a simple mistake, the entire future of Green Gables changes. In the quiet rural town of Avonlea on Prince Edward Island in the 1870s, the middle-aged siblings Marilla and Matthew Cuthbert decide to adopt a boy from an orphanage to help with the farm work. When Matthew goes to the train station to collect the boy, he instead finds a scrawny, freckled, eleven-year-old girl with long braids of red hair waiting for him, a girl whose imagination is already transforming the station platform into a castle. This is Anne Shirley, and through a misunderstanding in the orphanage’s message, she has been sent to Green Gables by mistake.

The story follows Anne as she desperately tries to win over the stern Marilla, who insists a girl is no use to them, while the shy, gentle Matthew quickly grows attached. Anne reveals her troubled past, having been passed between harsh homes and orphanages, and her deepest longing is simply for a place to call home and someone to love her. Marilla, moved by her hard life and touched by her strange, radiant spirit, agrees to let her stay on a trial basis. From that moment, life at Green Gables and in Avonlea is never quiet again.

Anne is a whirlwind of passionate disasters and lyrical joys. She renames the familiar local landmarks, turning a small pond into the Lake of Shining Waters and an avenue of apple trees into the White Way of Delight. Her fiery temper leads her to break her slate over the head of the handsome and teasing Gilbert Blythe after he mocks her red hair, launching a rivalry that lasts for years. She accidentally gets her best friend, the plump and sensible Diana Barry, drunk on raspberry cordial that she mistakes for raspberry juice, nearly ending their friendship. In a fit of vanity, she dyes her hated red hair using a bottle of hair dye she is told is black, only for it to turn a horrible shade of green, forcing Marilla to cut it all off. She also commits the social sin of punching a rug in front of the town gossip, Mrs. Rachel Lynde, after Rachel cruelly calls her skinny and ugly.

These misadventures form the core of Anne’s childhood, but the deeper narrative arc follows her growth from an impulsive, insecure orphan into a accomplished and beloved young woman. Through the steady, dry-witted guidance of Marilla and the devoted, silent support of Matthew, Anne learns to channel her dramatic imagination. She excels in her studies, determined to earn a teaching license so she can stay near Green Gables. After years of refusing to speak to Gilbert, a moment of crisis helps her forgive him, and they become close friends and academic rivals, both winning scholarships to the Queen's Academy. The story reaches its emotional climax when Matthew, having secretly saved to buy her a fashionable dress for her first concert, suffers a fatal heart attack upon returning home. This loss devastates Anne and Marilla, but also solidifies Anne’s final decision: to give up her scholarship to the prestigious Redmond College and stay at Green Gables to care for Marilla, whose eyesight is failing. In her ultimate act of choosing family over ambition, Anne finds a new path, teaching at the local school while living in the home she has finally made her own.