Mrs. Danvers is the antagonist of Daphnée Du Maurier's novel Rebecca, made internationally famous by its movie adaptation by Sir Alfred Hitchcock. An icy, stern and imposing figure never ever seen smiling, Mrs. Danvers (portrayed in the movie by Judith Anderson) has been widely praised as one of the most memorable movie villainesses ever seen. She is is the housekeeper of the Manderley estate, property of the wealthy aristocrat Maxim de Winter, and harbors an unhealthy adoration for Maxim's late wife, the eponymous Rebecca.
In the beginning of the story, a young woman whose name is never revealed meets Maximilian de Winter, a widower aristocrat, in Monte Carlo. The two fall in love and get quickly married, and Maxim takes his new wife to his country manor of Manderley, where she is welcomed warmly by all the servants working there. The new Mrs. de Winter then meets the housekeeper Mrs. Danvers, who greets her rather coldly but does not display any open dislike.
Mrs. Danvers shows her new mistress her quarters and her study, where all the bedsheets and even the pieces or paper bear an embroidered 'R', the initial of Maxim's first wife, Rebecca: a beautiful and sophisticated woman who seemed to be the perfect noble lady in all regards, and who died a year ago in mysterious circumstances, when her yacht sank.
As the story progresses, it becomes more and more obvious that Mrs; Danvers despises her new mistress, whom she regards as a pale substitute, and that she admired Rebecca to the point of adoration. An adoration unveiled slowly but surely, each second more disturbing than the previous one.
The new Mrs. de Winter, who comes from a modest background, has difficulties to adapt to her new role and to cope with Rebecca's haunting presence, which marks the manor as if she was still living there. A presence kept alive by Mrs. Danvers, who keeps Rebecca's old bedroom perfectly tidy and organized like a shrine of some sort. Mrs. Danvers uses her new mistress' doubts against her, always suggesting or making seem that Rebecca was a better lady and even a better wife, to such extent than the new Mrs. de Winter begins to doubt Maxim's love for her, believing that he still prefers Rebecca. It also appears that Rebecca's "cousin" Jack Favell, (in fact one of her lovers) frequently visits Manderley when Maxim is away, being in friendly terms with Mrs. Danvers.At some point, Mrs. de Winter orders Mrs. Danvers to get rid of everything in her quarters that belonged to Rebecca, stating that she is the new Mrs. de Winter. Mrs. Danvers complies, and in what first appears to be better dispositions towards her new mistress, she advises her to wear the same dress as one of Maxim's female ancestors, who is represented on a painting, for the upcoming costume party.
It soon appears that Rebecca wore the exact same dress in a costume party the year before, something that infuriates Maxim to the point of yelling at his wife. Distraught and confused, Mrs. de Winter flees to her room and enters a sort of trance. As she is standing near the open window, Mrs. Danvers approaches and nearly causes her to commit suicide, by telling her that no one will ever replace Rebecca.
Shortly after, Rebecca's sunken yacht is discovered. It appears that the ship was sabotaged so that it would sink at sea and that Rebecca's corpse is still inside, Maxim having identified another drowned woman as his first wife one year ago. Maxim is immediately suspected of having murdered Rebecca. He then confesses to his wife that he always hated Rebecca, who is then revealed to have been in fact a vain and dislikeable woman, whom he wed for an arranged marriage and who openly cheated on him many times, while always appearing as a paragon of virtue.
He also confesses that Rebecca died during a heated argument, in which she had claimed to be pregnant with an illegitimate baby that would inherit Maxim's name and title, driving him over the edge. Rebecca died when she hit her head in an accidental fall in the midst of the skirmish (in the original novel, Maxim purposely shot her). Maxim later sabotaged her yacht and put her corpse in, so that it would disappear at sea.
Mrs. Danvers and Jack Favell, who are convinced that Maxim killed Rebecca and that her unborn baby was Jack's, go to the police and try to have Maxim judged. However, it is ultimately revealed by a doctor whom Rebecca consulted under Mrs. Danvers' name that not only she could not have children due to a malformation of her uterus, but she was dying of a cancer. She then staged her "murder" by the hands of her husband, probably hoping that he would get arrested.
Now that Rebecca's suicide has been established, Maxim returns to Manderley, only to find it ablaze. His wife then welcomes him in a loving embrace, telling him that Mrs. Danvers set the manor on fire, for she would rather destroy it than witness them living happily in it. The demented housekeeper is last seen wandering in the midst of the fire, shortly before the blazing roof collapses killing her (in the novel, it is said that Mrs. Danvers fled before burning Manderley, never to be seen again).
In the final scene of the movie, the flames are seen devouring the embroidered 'R' on a pillow (in a fashion similar to the flames devouring the 'Rosebud' sledge in Orson Welles' masterpiece Citizen Kane) ending Rebecca's haunting grasp over those who knew her for good.