The story begins in the stillness of a London night, where Walter Hartright, a young drawing-master, encounters a mysterious woman dressed entirely in white. This chance meeting leads him to Limmeridge House in Cumberland, where he is engaged to teach water-colour painting to Laura Fairlie and her half-sister Marian Halcombe. Hartright soon discovers that the fragile, gentle Laura bears an uncanny and startling resemblance to the fugitive woman in white, whose real name is Anne Catherick. As the days pass, Hartright finds himself falling deeply in love with his pupil, despite her engagement to Sir Percival Glyde, a charming baronet with a hidden past and enormous debts.
The arrival of Sir Percival brings tension and suspicion to the household, particularly when an anonymous letter warns Laura against the marriage by describing the baronet's dark and ruthless character. Despite the warnings and the eerie similarities between Laura and the fugitive, the wedding arrangements proceed under the guidance of family lawyers and guardians. The mystery deepens when Anne Catherick vanishes into the shadows, leaving behind a trail of unanswered questions about her past imprisonment in a private asylum. The narrative shifts perspectives as various characters bear witness to the unfolding events, recording the gradual tightening of a conspiracy orchestrated by Sir Percival and his enigmatic associate, Count Fosco. Ultimately, the plot develops into a desperate race to uncover the truth behind the identity swap that threatens to rob Laura of her fortune, her sanity, and her very existence.
