There are three parts to Jean Rhys' novel Wide Sargasso Sea, and each part takes place in a different setting. Part I recounts the childhood and young adulthood of the central character, Antoinette Cosway. The story begins in 1839 in Jamaica, which is at that time part of the British Empire. It has been six years since the abolishment of slavery in the Empire, and the social situation on the island is chaotic. Antoinette lives on the impoverished Coulibri Estate in Jamaica, and as a child of mixed racial heritage, she is isolated from her peers, being neither black nor white.
In Part 2, the setting moves to another island in the Carribbean, Dominica, and specifically, a city called Massacre. Antoinette has entered into an arranged marriage with an Englishman, Edward Rochester, and the two newlyweds journey to a "honeymoon house" on Dominica which Antoinette has inherited from her mother. Although Antoinette is deeply in love with Rochester, he, on his part, is repulsed by her exotic, unrestrained nature. Regretful that he has allowed himself to marry only to fulfill the aspirations his family has had for him, he takes Antoinette, whom he will always take care of but whom he will never love, away from her island environs and sets sail for England.
Part 3 takes place at Thornfield Hall, Rochester's home in England. The dreary, misty weather here is a stark contrast to what Antoinette is used to, having grown up in the sun-drenched Carribbean, and Rochester, believing her to be mad, keeps her locked up in the attic with a caretaker, Grace Poole. Antoinette Cosway has become Bertha Mason, the monstrous madwoman in another classic novel, Charlotte Bronte's Jane Eyre.
Setting is central to the main themes in Wide Sargasso Sea. The author has written the book to present an opposing perspective to that in Jane Eyre, and she has clearly delineated the complete differences in perception of people and values between the darker races of the colonized in places such as the Carribbean, and the staid white citizens of the British Isles.