Set in an unnamed African country after independence, the book is narrated by Salim, an ethnically Indian Muslim and a shopkeeper in a small, growing city in the country's remote interior. Salim observes the rapid changes in Africa with an outsider's distance.
Salim, the protagonist, grows up in the Indian community of traders on the east coast of Africa. Feeling insecure about his future in East Africa, he buys a business from Nazruddin in a town at "a bend in the river" in the heart of Africa. When he moves there, he finds the town decrepit, a "ghost town", its former European suburb reclaimed by the bush, and many of its European vestiges ruined in a "rage" by the locals in response to their suppression and humiliation during the colonial times. Old tribal distinctions have become important again. Salim trades in what people in the villages need, pencils and paper, pots and pans, various household utensils. Soon he is joined by his assistant Metty who comes from a family of house slaves his family had maintained in the east. One of his steady customers is Zabeth, a "marchande" from a village and a magician, too. Zabeth has a son, Ferdinand, from a man of another tribe, and asks Salim to help him get educated. Ferdinand attends the local lycée that is run by Father Huismans, a Belgian priest who collects African masks and considered a "lover of Africa". Life in the town is slowly improving. Salim’s decision to move there gets vindicated when he learns that the Indian community on the East coast is getting persecuted. But he feels not secure either. Metty says of the local Africans "... they are malins", "because they lived with the knowledge of men as prey." A local rebellion breaks out, and the Indian merchants live in fear. Soon white mercenaries appear and restore order. After peace has returned Father Huismans goes on a trip. He is killed by unknown assailants and nobody cares. Afterwards, his collection of African masks is denounced as affront to African religion. An American visitor pillages most of it and ships it home –"The richest products of the forest".
The town now develops becoming what it always was, a trading center for the region. Government agencies spring up. European salesmen and visitors arrive. Salim’s friends Mahesh and Shoba become successful with their new Bigburger franchise. The new army arrives – "poachers of ivory and thieves of gold". The portrait of the President – "the Big Man" – is displayed everywhere. A new section of town is built, the "State Domain", to showcase the President’s vision of a new Africa. Yet buildings are shoddy, tractors of the agricultural center never go to work, and much of it falls quickly into some disrepair, – Salim calls it a "hoax". The Domain is soon converted into a university and conference center. Salim is visited by Indar who grew up with him on the East coast, then went to England to study and now has become a lecturer at the new institution. He takes Salim to a party in the Domain to meet Yvette and Raymond. Raymond had been the advisor and mentor of the President. Although in charge of the Domain, he finds himself now outside of the center of power. Loyal to the President, he continues to write for him hoping to be recalled to the capital. Salim whose experience with women has been limited to prostitutes is intrigued by Yvette, Raymond's much younger wife. Later, after Indar departs with the steamer, Salim and Yvette enter an adulterous affair, right under Raymond's eyes. Eventually, the liaison breaks down, Salim hitting her and spitting on her, between the legs.
Raymond's attempts to please the Big Man are not successful, instead the President publishes "a very small, brief book of thoughts, Maximes, two or three thoughts to each page, each thought about four or five lines long." Like others Salim is forced to buy a stack for distribution. The local youth group displeases the President and is denounced in one of his propaganda speeches. As a result unrest grows, corruption and extortions become more prevalent, and a "Liberation Army" forms in the underground. They reject the President, his cult of the black Madonna, his vision of Africa, and want to return to the "truthful laws" of the ancestors. Salim looks for a way out. He travels to London where he meets Nazruddin. Nazruddin after having sold his business to Salim, had first moved to Uganda, left it because of persecution, moved then to Canada, left it because of its capitalistic rapaciousness, and finally landed in London becoming a landlord. He bemoans the lack of security for honest businessmen, – there is no safe place. Salim becomes engaged to his daughter, but soon leaves returning to his place in Africa. Upon arrival he learns that he has been expropriated, the President’s new program of "Radicalization" has transferred his business to a local. Théotime, a "state trustee", is ignorant and lazy and retains Salim as manager and chauffeur. Salim recognizes that all is lost. He had hidden some ivory on his property, but betrayed by Metty, is found out and put in jail. He is presented to the commissioner, now Ferdinand, who has moved up in the administration after his training in the capital. Ferdinand tells him that there is no safety, no hope, and everybody is in fear of his life. "We’re all going to hell, and every man knows this in his bones. We’re being killed. Nothing has any meaning." He sets Salim free telling him to leave the country. Salim takes the last steamer before the President arrives at the town to supervise an execution of a yet-to-be-determined victim. During the night, there is a battle on the ship, as rebels try to kidnap it. The attack is repelled, but the attached barge, full of Africans, is snapped loose and drifts down the river.
This Latin phrase is still visible to Salim on the granite base of a ruined European monument near the dock. Later Father Huismans explains him its meaning. "He approves of the mingling of the peoples and their bonds of union", derived from Virgil's Aeneid. The hero lands on the shores of Africa, falls in love with the local queen and wants to settle, and his mission, the migration to Italy, is in danger. The gods intervene: they do not approve of a settlement in Africa nor of the mingling of the peoples. In the motto, however, three words were altered to reverse the original meaning. A second Latin phrase is encountered by Salim: Semper aliquod novi, the motto of the lycée. The original phrase by Pliny the Elder meant that there is always something new out of Africa (ex Africa). Huismans applied it jokingly to the unique masks and carvings with religious quality he had collected.
Naipaul is recognized as a "magnificent novelist", and A Bend in the River has been described as a "full-bodied masterpiece". Yet criticism arises about his opinions and viewpoints. He has been accused of being a "neo-colonialist", and in this novel post-colonial Africa is depicted as spiraling into hell. He has also been accused of being "infected by an ancestral communal resentment" against blacks. Whitaker indicates that Salim's plight as an outsider, a member of the Indian community in Africa, is credibly rendered, but takes Naipaul to task for ascribing to African people a "mysterious malevolence". Irving Howe admires Naipaul's "almost Conradian gift for tensing a story", the psychic and moral tension of the novel, and its "serious involvement with human issues".
He rejects the notion that Naipaul is an apologist of colonialism. Howe contrasts the foreground space occupied by Salim with the background acts set in motion by the Big Man. The Big Man never appears but finds a voice in Raymond, the white intellectual who gets dumped later. Howe bemoans the fact that, as he sees it, Naipaul offers no hope, and that he allows "the wretchedness of his depicted scene" to become "the limit of his vision". Selwyn Cudjoe thinks the novel depicts "the gradual darkening of African society as it returns to its age-old condition of bush and blood" and thinks this pessimistic view indicates Naipaul's "inability to examine postcolonial societies in any depth". The novel examines "the homeless condition of the East Indian in a world he cannot call home" and shows in Salim's case his passage to free himself from "the constricting ties to his society's past".
Imraan Coovadia examines Naipaul's Latin quotations and accuses him of misquotations and manipulation opining that he tries to polarize the readers and to evoke fear, disgust and condescencion. Raja suggests that the novel is less about a conflict of modernity and Third World development, but more about a representation from a bourgeois perspective, Salim being not interested in revolutionary goals but a profitable enterprise. He asserts that Naipaul is not a postcolonial author but a "cosmopolitan" one (as defined by Timothy Brennan), who offers an "inside view of formerly submerged peoples" for target audiences that have "metropolitan literary tastes".
In 2001, without specifically referring to this novel, the Nobel Literature Prize Committee indicated that it viewed Naipaul as Conrad’s heir as the annalist of the destinies of empires in the moral sense: what they do to human beings. In Heart of Darkness, Joseph Conrad presented a dark picture of the same region at the beginning of European colonization; this type of depiction of Africa is also found recast in Naipaul's novel.
Like Conrad, who in Heart of Darkness does not name the big river, Naipaul does not name the river in this novel, nor the town at its bend, nor the country or its president. Yet there are possible identifiers. Thus the reader learns that the town is located in the heart of Africa, at the end of the navigable river, just below the cataracts, and the European colonizers had been French-speaking, likely Belgians. Naipaul's description has been interpreted to point to the town of Kisangani on the Congo river. A link between the "Big Man" and President Mobutu of Zaire was drawn by some reviewers. Indeed, it is profoundly apparent from an early stage in the novel that it is set in Kisangani during the Mobutu era.
Naipaul credits his extramarital affair with Margaret Gooding for giving A Bend in the River and his later books greater fluidity, saying that these "in a way to some extent depend on her. They stopped being dry.”
Although A Bend in the River did not win the Booker Prize, despite being shortlisted, it is discussed by two characters in The Inheritance of Loss by Kiran Desai, which won the prize in 2006.