At the turn of the century on Prince Edward Island, Matthew Cuthbert and his sister Marilla decide to take on an orphan boy as help for their farm. But they get an unexpected jolt when they're mistakenly sent a girl instead: Anne Shirley.

Anne Shirley, now a schoolteacher, has begun writing stories and collecting rejection slips. She acts as Diana's maid of honor, develops a relationship with Gilbert Blythe, and finds herself at Kingsport Ladies' College. But while Anne enjoys the battles and the friends she makes, she finds herself returning to Avonlea.

Anne is persuaded to join her fiance, Gilbert, in New York City as he begins his tenure at a major hospital. However, any chance of lasting happiness is dashed when Gilbert enlists to serve in The Great War in Europe. Anne stays behind and takes up writing, but learns that contact has been lost with Gilbert. Seeing no other option, Anne decides to venture to Europe herself to find him. In doing so, she begins an adventure that will challenge her wits and imagination to the limit.

Anne, now a middle-aged woman, is troubled by recent events in her life. When a long-hidden secret is discovered under the floorboards at Green Gables, Anne retreats into her memories to relive her troubled early years prior to arriving as an orphan at Green Gables and being adopted by the Cuthberts.