From Amazon.com: Wide Sargasso Sea is the story of Antoinette Cosway, a Creole heiress who grew up in the West Indies on a decaying plantation. When she comes of age she is married off to an Englishman, and he takes her away from the only place she has known--a house with a garden where "the paths were overgrown and a smell of dead flowers mixed with the fresh living smell. Underneath the tree ferns, tall as forest tree ferns, the light was green. Orchids flourished out of reach or for some reason not to be touched."
The novel is Rhys's answer to Jane Eyre. Charlotte Brontë's book had long haunted her, mostly for the story it did not tell--that of the madwoman in the attic, Rochester's terrible secret. Antoinette is Rhys's imagining of that locked-up woman, who in the end burns up
the house and herself. Wide Sargasso Sea follows her voyage into the dark, both from her point of view and Rochester's. It is a voyage charged with soul-destroying lust. "I watched her die many times," observes the new husband. "In my way, not in hers. In sunlight, in shadow, by moonlight, by candlelight. In the long afternoons when the house was empty."
A sensual and protected young woman, Antoinette Cosway grows up in the lush natural world of the Caribbean. She is sold into marriage to the coldhearted and prideful Rochester, who succumbs to his need for money and his lust. Yet he will make her pay for her ancestors' sins of slaveholding, excessive drinking, and nihilistic despair by enslaving her as a prisoner in his bleak English home.
In this best-selling novel Rhys portrays a society so driven by hatred, so skewed in its sexual relations, that it can literally drive a woman out of her mind.
Note: There are many editions of this book, at several price points. An edition sold by Barnes and Noble seems to be the cheapest, and can be found at http://www.barnesandnoble.com/w/wide-sargasso-sea-jean-rhys/1100878232?ean=9780393308808.