Jeet Thayil
Faber & Faber, 304pp, £12.99

This novel begins and ends with the same word: "Bombay". That city, the narrator tells us in the opening sentence, is the "hero or heroin of this story" - an intentional pun on "heroin", since drugs curdle through the narrative as they do through the bodies and brains of the characters. Narcopolis spans three decades, journeying deep into the Bombay underworld and painting an evocative portrait of those "invisible entities" on the margins of society in whose midst a murderer prowls.

“The past is a foreign country," said L P Hartley, a phrase echoed by the narrator who is trying to recall his hazy past "as I would the landscape and light of a foreign country", trawling through his memories of how he got into trouble in New York and was sent back to Bombay. Depicting the way opium ravages the memory and induces extreme psychical states, Jeet Thayil evokes the intense, feverish dreams and nightmares of addicts pushed to the edge.

Pain, too, is described as if it were a geographical territory, at the centre of which are the eunuch Dimple, whom the narrator encounters at Rashid's opium den, and a Chinese refugee named Mr Lee. For Dimple and Mr Lee, "It was a bond between them, this itemising of pain. In pain, [Mr Lee] said, as if it were a country. As if he were saying, I am in Spain." Thayil fills in Mr Lee's brutal back story and his family's tortured past in China under Mao. When he was beaten in prison, "the pain slowed time . . . A single moment became something impossibly complex that took all his resources to endure."

Thayil eschews a conventional narrative and in doing so he is able more accurately to reflect his characters' states of mind, trapped as they are inside their suffering. "He lost faith in linear time," he writes of Mr Lee. "His mind skipped years, slipping backward or forward without regard for chronology."

As well as physical pain, there are emotional wounds, too: for Dimple, the memories of being abandoned by her mother, of knowing she was unloved. For her, these are as persistent as her bodily discomfort. Little wonder that "forgetfulness was a gift, a talent to be nurtured". The drugs given to her by Mr Lee make her feel that she was "beloved and not alone".

Thayil's depiction of the addicts' slow disintegration until they become "damaged stran­gers" and "inanimate objects", even to themselves, is devastating. "I lost myself", says the narrator, and the tricksy switches between the first and third person are apt, for these characters are ontologically troubled, startled by their own reflections.

Thayil not only shows the effects of addiction but also probes its causes, emphasising the psychological effects of living with systemic violence, in a place where "anything can happen to anyone at any time".

Narcopolis is pervaded by a profound yearning to escape. "Dare to dream," Mr Lee advises Dimple. It is also a novel about books and art, and how they can humanise us. There is catharsis when Dimple and Rashid watch the 1970s Bollywood film Hare Rama Hare Krishna, about a girl who runs away from an unloving family. Dimple teaches herself to read and writes a story about a child living in "a world in which only pain was real."

Thayil shows us extremes of dehumanisation but there is also hope amid the horrific brutality. As Dimple says to the narrator in a dream: "You should listen. Even if you can't bear it, you should listen." And that is precisely what this novel asks us to do: to listen to the most vulnerable people who usually don't have a voice.

Anita Sethi is a writer and broadcaster