A chance encounter with a mysterious woman dressed in white on a moonlit road sets off a chain of events that threatens the sanity and inheritance of a young drawing master. Walter Hartright, the protagonist, finds himself entangled in a complex web of deception, identity theft, and institutional corruption after accepting a position at Limmeridge House. He must navigate the rigid social hierarchies of Victorian England while attempting to protect Laura Fairlie from the machinations of the charismatic yet malevolent Count Fosco and Sir Percival Glyde. The narrative employs a multi-perspective, epistolary framework, utilizing various testimonies and documents to reconstruct the truth behind a sinister conspiracy.

This work is widely regarded as one of the earliest and most influential examples of the sensation novel, a genre that prioritized suspense and domestic intrigue. Critics often highlight the technical sophistication of the multi-narrator structure, which allows the reader to piece together the mystery alongside the characters. The character of Count Fosco is frequently cited as a seminal figure in the development of the literary villain, noted for his intelligence and lack of moral compass. The novel remains a staple of Victorian studies, valued for its critique of the era's marriage laws and the vulnerability of women within the legal system.