The first part of Wide Sargasso Sea is told from the perspective of Antoinette Cosway, a young girl who lives on an estate on the island of Jamaica (a British colony) with her mother and brother and a dwindling group of the family's former slaves. As the novella begins in 1834, the slaves have been granted emancipation and the island is in a state of total upheaval. Former slaveholders have yet to be compensated for the loss of human labor and as a result their estates are quickly falling into disarray. Coulibri, the mansion that is home to Antoinette and her family, is no exception. The situation is dire: the family has no more money and is on the verge of certain death.
The Cosways are outsiders in Jamaica. They do not fall into either of the island's dominant racial and social groups; that is, they are neither wealthy white property holders nor impoverished but recently freed black slaves. Instead, we learn in the opening pages, Antoinette and her mother and brother are Creoles, or whites of European descent born in the West Indies. In fact, Antoinette's beautiful mother Annette was born on the nearby island of Martinique (a French colony), and came to Jamaica as the much-younger second wife of Alexander Cosway, Antoinette's now-deceased father. The other white people in Jamaica apparently never approved of their marriage and therefore never accepted the Cosways as part of their circle. Now that the family is poor, they no longer even command the respect of the black people, who comprise the vast majority of the island's population due to their economy's years of reliance on slavery.
As the family's situation approaches the point of crisis, Antoinette's mother grows increasingly unstable. For a while she insists on going horseback riding every day, even as her riding habit gets torn and shabby, but after her horse is poisoned she refuses to leave the house and becomes thin, silent, and sullen. Antoinette gets concerned when her mother starts talking to herself and pacing up and down the glacis while the servants and townspeople point and stare. When she tries to comfort her mother, however, Annette pushes her daughter away and begs to be left in peace. The only person Annette seems to want anything to do with is her mentally and physically handicapped son Pierre, Antoinette's younger brother. A doctor comes to assess Pierre one day, but never returns. In the meantime, Annette grows more and more moody and distant.
Estranged from her mother, Antoinette spends most of her time either alone or with Christophine, the loyal black servant who was a wedding gift from Alexander to Annette. Several of the other servants are afraid of Christophine, who is reputed to practice the dark arts. She sings to Antoinette and finds her a playmate named Tia. For a while Antoinette and Tia go swimming together every day, but then Tia steals Antoinette's pennies and dress and calls her a "white nigger." Antoinette is ashamed.
She returns home to find visitors at the house for the first time in ages. They plan to take up residence at the neighboring plantation of Nelson's Rest. Antoinette's mother is delighted to have company, but Christophine is distrustful of the newcomers, who she believes will institute a new and legal but equally cruel form of slavery on the island. Antoinette, meanwhile, is so unaccustomed to strangers that she runs away in shyness at the sight of them. Her mother scolds her for this behavior and for not having a clean dress to wear. Christophine explains that Antoinette has no other dress; the next day yards of muslin arrive. Antoinette speculates that her mother must have sold her last ring to pay for the fabric.
The arrival of new neighbors seems to rejuvenate Antoinette's mother and things seem to improve at Coulibri for a time. The Luttrells lend Annette a horse to ride and as a result she is seldom home. Antoinette decides to stay away from the house too, and spends her days in solitude, wandering about the wild tropical landscape.
The opening pages of Wide Sargasso Sea set a dark and ominous tone that will pervade the entire work. Two instances of death occur within the first two pages of the text - that of the Cosway's neighbor Mr. Luttrell and that of Annette's beloved horse. Antoinette describes both deaths in succinct and unemotional terms. Mr. Luttrell, she says matter-of-factly, got impatient waiting for the money he was owed for his slaves, and so he "shot his dog, swam out to sea and was gone for always." The horse, she explains, was "was lying down under the frangipani tree... he was not sick, he was dead and his eyes were black with flies." Such images of decay reinforce Rhys's theme of British imperialistic decline.
The first lines of the novella also serve to establish the undercurrent of racial tension essential to Rhys's post-colonial revision. "They say when trouble comes close ranks, and so the white people did. But we were not in their ranks," Antoinette nonchalantly remarks. Her words set up an immediate dichotomy between "us" and "them," between outcast and insider. There is, however, yet another element to this complex racial situation. In the work's beginning lines Antoinette refers to "the white people," but several paragraphs later she mentions, with similar detachment, "the black people" who also apparently view the her family with scornful derision.
The reason for the family's status as racial "other" soon becomes clear: Antoinette and her mother and brother are Creoles, or light-skinned European descendants born in the Caribbean but perhaps with some mixed racial heritage, although Rhys never makes this explicit. Antoinette is frequently called a "white cockroach" and a "white nigger," terms which perhaps imply some degree of interbreeding, but which could also simply denote inferiority. In Charlotte Brontë's Jane Eyre, meanwhile, the Creole madwoman is definitively dark-skinned.
As a result of their marginalized racial status, the Cosway family lives in almost complete isolation - "marooned" as Annette puts it, "abandoned" and "forgotten." Young Antoinette feels this seclusion all the more acutely because her mother consistently rejects her in favor of her younger brother Pierre. Antoinette, therefore, is an outcast even within her own family. Except for a short-lived friendship with Tia, she spends her days alone, wandering about remote parts of her family's dilapidated estate and attempting to convince herself that ants and snakes are "better than people." When visitors finally come to the house she has become so used to being a recluse that she runs away and hides. Antoinette's reclusive behavior not only emphasizes her adolescent isolation, it also subtly prefigures her hellish life to come as Rochester's mad wife in the attic.
Wide Sargasso Sea contains many autobiographical elements, and it is worth noting that Antoinette's mother and father seem to be based at least loosely on Rhys's own parents. Critic Anne B. Simpson writes that Rhys's father, like Old Mr. Cosway, "flirted playfully with women other than his wife, and spent money improvidently"; Rhys's mother, meanwhile, was "frigidly inaccessible" much like Annette. As a result, Rhys, like Antoinette, spent her most of her childhood in solitude.