Kazuo Ishiguro says of his most recent novel that "the reader is on a sort of parallel journey" with the diffident 31-year-old narrator Kathy. Like her, one slowly realises the truth about her life and that of her friends Tommy and Ruth; they are clones who will one day donate their organs for transplant.

"If information does trickle gradually it's because the children themselves do not realise who they are," he explains.

Their boarding school, Hailsham, set in a rural landscape, is poorly equipped but run by stimulating teachers called guardians, who shelter them from the world. But certain rituals and routines are unsettling: the regular medical checks the children have to undergo and the way their art is whisked away to an unknown location.

Words like "donations" and "complete", "models" and "possible" have a sinister, unfathomable ring and they fear the nearby wood, where a boy was found tied to a tree with hands and feet chopped off.

Unaccountably, there is no mention of parents, of home, of holidays. Above all, they know themselves to be different: "At that stage in our lives any place beyond Hailsham was like a fantasy land; we had only the haziest notions of the world outside and about what was and wasn't possible there." On one occasion they try to track down a "model" that could give them an insight into who they are and what the future holds in store for them. Ishiguro's understated narrative is about young people who are in limbo, trying to make a meagre life for themselves. In a telling moment, Kathy realises: "These dark byways of the country existed just for like of us, while the glittering motorways with their huge signs and super cars were for everyone else."

Exploitation is a key theme for Ishiguro: the butler inThe Remains of the Day and the widow in Nagasaki in The Unconsoled (1995). In Never Let Me Go, some are sacrificed so that others might live; Kathy's pared-down style conveys movingly her sense of worth and the dignity that should be accorded to every section of society, a concern in all Ishiguro's work.

Kazuo Ishiguro will be at the Oxford Literary Festival on Sunday at 6pm in the Oxford Union.

Never Let Me Go is published by Faber at £16.99