The events described in the novel take place in the 1850s in England. A young painter from London, Walter Hartright, being recommended by a friend of his - Italian Professor Pesca, got a position of an art teacher at Limmeridge House in Cumberland, which belonged to Frederick Fairlie. Before Walter left he came to say good-bye to his mother and sister. On his way home at hot summer night, he met a very strange woman on the empty street, who was dressed in a completely white dress. And they went on together. When Walter mentioned about the places, he was going to visit, the stranger showed a sudden agitation. But she spoke with love about Mrs. Fairlie, the late owner of the Limmeridge House. And then she mentioned with anger of some baronet from Hampshire, but without naming him. Walter helped the strange woman to catch a cab, and right after she left he saw a carriage with two men looking for a “woman in white”. They needed to return her to the madhouse, where she managed to escape from.
Walter came to Limmeridge and met those residing there: Marian Halcombe, a daughter of the late Mrs. Fairlie from the first marriage, her sister Laura Fairlie, and Laura’s uncle – Frederick Fairlie, who was a bachelor and rather selfish. Walter told Marian about the strange woman he had met in London, and Marian being intrigued, found the mention of a girl Anne Catherick in her mother’s letters. Mrs. Fairlie got attached to the little Anne because of her resemblance with Laura, and Anne in her turn got attached to Mrs. Fairlie, and responding to her with enormous love, swore to be always wearing only white. At one moment Walter realized the terrifying likeness between Anne and Laure, with the only difference: Anne was thinner and it seemed that she had experienced some serious grief. Both Marian and Walter kept their discovery in secret.
Meanwhile, as it usually happens, Laura and Walter fell in love, but both stayed silent of their love, because they understood all the difference in their social state, and one more obstacle was on their way – Laure was engaged with a baronet, the one that her father had blessed her with. Sir Percival Glyde, the owner of Blackwater Park in Hampshire, was a wealthy and respected person. When Walter learnt about this, the strange woman’s vague words about a baronet from Hampshire came to his mind. That day Laura got a not signed letter, which warned her about her future husband, who was described in the letter as an evil and very bad person
Soon, walking around, Walter saw Anne Catherick at the Limmeridge cemetery washing the monument over Mrs. Fairlie’s grave. From their conversation Walter guessed that Anne was the one who had sent the anonymous letter to Laura. It turned out that it had been Sir Percival, who had put her into the madhouse. After all these events Walter left Limmeridge, and in order to forget his love he went into the Central America with archeologists to explore the New World.
When Percival came to Limmeridge the first thing was that he was asked to explain everything concerning Anne Catherick. Sir Percival did that, and as a proof he showed a letter from Mrs. Catherick, Anna’s mother, who wrote that her daughter was put into the madhouse with her agreement and for Anna’s own sake. The letter was strangely cold and brief. To the very last minute both Laura and Marian hoped something would happen and the marriage cancelled, but the miracle did not happen. Sir Percival and Laura Fairlie got married in the Limmeridge church and went off on their honeymoon trip to Italy. A half of a year passed, they returned to England and resided in Blackwater Park House. Marian came as well to be always with Laura.
With the Glydes came another married couple – Count and Countess Fosco. Countess Fosco was Laura’s aunt, she used to be quarrelsome and vainglorious in some way, but now she was completely devoted to her husband, did not leave her eyes from him, and was always ready to do anything he said. Count Fosco was extremely fat, invariably polite, too amiable, constantly showed signs of affection to his wife, adored white mice, and was carrying them all the time in a big cage. But Marian noticed unusual power in Count Fosco, as she noted “even if he had married a tigress, he would have tamed it as well”.
Walking around the mansion territory Laure met Anne Catherick, who again warned her about her husband, and asked her not to trust him. Sit Percival, in his turn, desperately needed money, and wanted Laura to sign some document without reading it, which Laura refused to do. The husband threatened her, but Count Fosco managed to soften the situation. Fiancé gloss and charm of Sir Percival had vanished long time ago, he became rough with his wife, and even reproached her for feelings to the teacher of drawing (Percival guessed about that). Count and Countess tried to prevent Marian to contact with their family attorney concerning the document Laura was asked to sign. The Foscos did anything they could to intercept a letter, and once Countess even gave a girl, who was supposed to pass the letter in London, some sleeping medicine.
Marian suspected a conspiracy against Laura, and in order to be convinced in that, overheard the conversation between Count Fosco and Sir Percival. The conspiracy really existed, but Marian could do nothing of it, because that night she had caught a very severe cold, and had lied down with a fever. Using Marian’s sickness as a chance Count Fosco, with his wife and Sir Percival’s support put into action his malicious plan. They took Marian into the room in the wing of the house, where nobody lived, and said Laura that her sister had left. And that’s how they lured Laura to leave Blackwater Park for Limmeridge, where Marian was said to be. But in London Laura was put into the madhouse under the Anne Catherick’s name, where poor girl had been before kept in. Meanwhile in London in Fosco’s house died Lady Laura Glyde, who stayed at her aunt’s house on her way to Limmeridge. And now between Laura’s money and her husband stayed nothing.
When Marian recovered she had learnt of an awful event that had taken place, she tried to do her best to look into the case. She managed to find Laura, who was broken, left without money and name. With the help of her savings Marian bribed some girl working in the madhouse, and saved Laura. From the long expedition returned Walter Hartright and learnt about what had happened. He decided to visit Limmeridge, the place where his love was born. At the cemetery he met two women, those were Marian and Laura. Laura had really changed, and her resemblance with Anne Catherick became even more vivid.
Walter rented an apartment, where they all began to live. With the bound efforts Marian and Walter did their best to help Laura to recover and put herself together. Walter decided to return Laura’s name. Having come to the conclusion that Sir Percival put Anne into the madhouse with a purpose, Walter tried to learn what the reason was, and what awful secret Sir Percival Glyde had. He visited Anne’s mother, but Mrs. Catherick refused to help Walter, but showed that she really hated Sir Percival and wished him nothing but death.
Putting together all his inquiries, Walter came to the conclusion that Percival’s parents had not been married, and that’s why he had no rights on the title, and on all the possessions. Many years ago, when Percival decided to forge his parents’ marriage in the church register, he was cut by Mrs. Catherick, and that’s how she learnt about his big secret. But Mrs. Catherick and Sir Percival were suspected in a relationship, and thus Mrs. Catherick had no respect many years, which was the source of her hatred to Percival. The reason Anne was put into the madhouse, was that she said Percival that would tell everyone his secret, but she knew nothing, and was a poor victim of the strongest and richest of this world.
When Walter got closer and closer to the outcome, Percival felt the danger and decided to act. He got to the church, and decided to put on fire the register, but got trapped in the church and died himself. Only one person stayed, who knew all the truth, and had proofs was Count Fosco, but he was hard to get.
One day Walter and his old friend Pesca happened to be in the theatre, where Count was as well. Walter asked Pesca if he knew that stout man and Pesca did not. But what Walter noticed was that Count Fosco had to know Pesca, because he really got frightened when he saw him. As it turned up Pesca was a member of a secret brotherhood, as well as Fosco. But Fosco had betrayed the interests of his brotherhood, and lived in a wait for inevitable revenge. Walter came to Fosco and made him write down the story of his and Sir Percival’s fraud, as an unmasking letter with all the details described was lying on Pesca’s table and would be opened if Walter didn’t come back at appointed time. So Fosco with the self-content so characteristic of his wrote a story, where he described every little detail.
The most important detail was the difference in dates, as real Laura Fairlie arrived to London after the day Anne Catherick died in Fosco’s house. Basing on this evidence Walter managed to prove that Laura was alive, and it was Anne Catherick, who had been buried. The note on the grave was changed. Anne Catherick found peace the way she wanted – with Mrs. Fairlie, the one she loved so much. Laura and Walter got married and their lives came to normal.
After a while Walter visited Paris on business, and there he accidently saw a body of Count Fosco being dragged out of the Seine. The body had no signs of violence, except two little cuts on his hand, where the mark of brotherhood was printed. Having returned to London Walter found at home neither Marian nor Laura with their little son. He got a note from his wife with a request to come to Limmeridge at once. There he was met by his close with news of Frederick Fairlie’s death, which made Laura the heiress of Limmeridge, and their little son Walter one of the wellborn landowners in England.