The novel is divided into three parts, which correspond to the three phases of the characters' lives: child, adult, donor. Kathy, Tommy and Ruth, are the protagonists, they are orphans who live and study in Hailsham collage, which is completely isolated from the surrounding world, absorbed into English countryside. The only adult figures who live there are the "guardians" which are teachers who provide education and take care of the children. Children learn Literature, History, Arts and their best works are selected by the mysterious "Madame" to create, apparently, a private gallery. During their childhood they strengthen their friendship which will last forever. Tommy, despite his feelings for Kathy, develops a romantic and sexual relationship with Ruth.
Chapter after chapter it's revealed to the reader and to the students that they are clones created to provide vital organs for normal people. At the age of 16-18 they move to the "Cottages" which are residential buildings where they start their first contacts with the external world. Here, they live in poor conditions, and although the numerous quarrels, Ruth and Tommy continue their relationship, while Kathy has many short-time relationships. They imagine who and how could be their possible "models" and, unfortunately, they discover that their model will be outcasts of society like prostitutes or drug-addicted. After ten years, Kathy becomes a "carer", while Ruth and Tommy become "donors". Kathy's work consists in controlling the reactions of the donors' bodies after the donations and to assist them. From an old friend, Kathy discovers that Ruth's first donation failed, so, she decides to take care of her old friend. The two girls have a trip and they call Tommy too; in the meanwhile Ruth confesses that she has always kept Kathy and Tommy distant one from the other because she has always known their feelings.
Trying to make amends, Ruth gives them Madame's address and suggests them to ask for a postponement for the donations. After the trip, Ruth makes her second donation and dies, so, Kathy becomes Tommy's carer and begins a romantic relationship with him. They decide to go to Madame's house to postpone his donation and the boy takes his works of art with him to show his personality, that he's in love with Kathy, and that he has a soul. When they meet Madame, they find out that Hailsham is a failed experiment in the world of cloning organized by the government with the purpose of having organ donations. The city is the result of a movement founded by Madame and a teacher to create a sense of humanity and morality in a world without scruples. The experiment fails because people change their opinion, but not in positive way, in fact they decide not to think about "carer" anymore.
