I hated the mountains and the hills, the rivers and the rain. I hated the sunsets of whatever colour, I hated its beauty and its magic and the secret I would never know. I hated its indifference and the cruelty which was part of its loveliness. Above all I hated her. For she belonged to the magic and the loveliness. She had left me thirsty and all my life would be thirst and longing for what I had lost before I found it. (p. 112)
Wide Sargasso Sea is a transformative work: it tells the story of the first Mrs Rochester from Charlotte Bronte's Jane Eyre -- the 'madwoman in the attic' -- from a feminist post-colonial angle.
The first part of the novel describes the childhood of Antoinette Cosway, a young Creole heiress whose life is changed (and not for the better) by the abolition of slavery in Jamaica. The family's home is burnt down, Antoinette's brother Pierre dies and their mother descends into madness, leaving Antoinette lost and alone. Then she marries an Englishman (Mr Rochester, though he's never named) who is recovering from fever.
The middle section of the novel is from Rochester's point of view: he is entranced by Antoinette's beauty, but disturbed by the rumours that reach him. Bad blood on both sides? A coloured lover? Witchcraft? Rochester tries to make Antoinette into a suitable wife: he calls her Bertha, because 'Antoinette' was her mother's name and her mother was mad; he attempts to quash her enjoyment of sex; he takes her away from everything she knows, to England.
The final section of the novel overlaps the narrative of Jane Eyre: Antoinette / Bertha, descending into madness, dreaming of fire.
Wide Sargasso Sea is beautifully written, and I admire it: I don't think I like it, simply because the relationship it describes is so dysfunctional, painful, doomed. It's a marvellous portrayal of mental instability -- both Antoinette's and Rochester's. (His narrative is increasingly fragmentary, and increasingly irrational.) Rhys certainly adds depth and dimension to Bronte's original story: in Wide Sargasso Sea, marriage is not a metric of female success, and 'madness' is not a simple case of bad blood.