Answer:
Rebecca begins with the sentence, "Last night I dreamt I went to Manderley again." The heroine, dreaming, sees herself as a ghost, flitting through the charred ruins of the once-beautiful mansion Manderley, where she once lived. When she awakes, she resolves not to speak of the dream, for "Manderley was ours no longer. Manderley was no more." The only person to whom she could speak of it, we realize shortly, is her husband, whose name we have not yet learned. Together, the couple is traveling through Europe, staying in small hotels to avoid meeting people they both know. They have recently been through a period of great suffering, connected to the destruction of Manderley, but the heroine does not reveal the nature of their predicament. Pieces of a vanished life float vaguely about: the heroine misses her dog, Jasper, and remembers how meals were prepared at Manderley, and then she thinks of a Mrs. Danvers, and a man called Favell, and wonders where they are now. Mrs. Danvers, we learn, was always comparing the heroine to someone named Rebecca, but details are not forthcoming. Instead, the heroine's thoughts turn to her younger self, years before, and then the real story begins, told in a flashback.
As a young woman, the heroine (whose given name we never learn) travels across Europe as a companion to Mrs. Van Hopper, a wealthy American lady. (It was a common custom in the 19th and early 20th century for wealthy, unmarried older women to pay young girls to travel with them, as both a servant and a friend with whom to converse. During their travels, the two women come to Monte Carlo, a resort city in the south of France. Mrs. Van Hopper, a nosy, gossipy, vulgar woman, recognizes a handsome middle-aged man who is staying in their hotel, and points him out to the heroine. He is Maxim de Winter, the owner of the famous estate known as Manderley, and he is reportedly in mourning for his wife, who died the previous year. Mrs. Van Hopper invites him to tea, but shows her most vulgar and crude side, to the great embarrassment of the heroine. Maxim treats her coldly, but later that day he sends a note to the heroine, apologizing for his rudeness at tea.
The following day, Mrs. Van Hopper is ill, and so the heroine has the day to herself. At lunch she runs into Maxim, who insists on eating with her, and then invites her to drive with him along the beautiful coastline. He shows warm and courteous demeanor--except at one place on the road, a place with a particularly striking view, where a bad memory seems to trouble him. At the end of the drive, the heroine notices a book of poetry in the car, and he insists upon giving it to her. She reads it that night, and notices that it is inscribed, "Max--from Rebecca." Then she recalls what Mrs. Van Hopper said about Maxim's dead wife: her name was Rebecca, and she drowned, accidentally, in a bay near Manderley.