Never Let Me Go is narrated retrospectively by Kathy H., who is thirty-one years old and introduces herself as a ‘carer’ who works with ‘donors’.  Her story begins some years earlier when she is a student at an institution called Hailsham, and the first chapters detail her friendships with a girl named Ruth and a short-tempered boy, Tommy, who is often teased by the other students.

Hailsham seems rather like a boarding school, but there are some peculiarities.  The students never leave the school or speak of having families, and they are sometimes visited by a woman known only as Madame, who chooses some of children’s artwork for her ‘gallery’.  Then one day, a teacher reveals to the students what it is that distinguishes them from other people.  They are in fact clones who have been created in order to provide donor organs.  Once they have grown up, they will begin to donate their vital organs, and consequently they will all die young.

In spite of this revelation, the students continue their lives without too much upheaval.  When they reach the age of sixteen they leave Hailsham and go to live with older students in an establishment called the Cottages.  They are now free to travel in the outside world, and have greater independence.  At this point, Ruth and Tommy form a relationship.

Kathy leaves the Cottages to become a carer, providing support to donors as they give up their organs.  It is assumed that she will soon become a donor herself, but she continues to be a carer for longer than most of her peers.  Consequently she is able to care for both Ruth and Tommy through their donations.

Before her final donation and her ‘completion’, Ruth suggests that Kathy becomes Tommy’s carer.  She also advises her to form a relationship with Tommy, saying that she always thought they should have been together, and adding that if they are in love then there is a possibility they may be granted a deferral in their donations.

Kathy begins to care for Tommy and a relationship develops.  By chance, Kathy sees Madame and discovers where she lives.  When she tells Tommy about the possibility of a deferral they decide to visit Madame and request it from her.  They travel to Madame’s house and find her with the Hailsham headmistress, Miss Emily.

But when they ask about the deferral, they are told by Miss Emily that there is no such thing.  She also explains that Hailsham was intended as a place where the clones could be educated and cultured; some had even tried to prove with exhibitions of the donor children's art that they were 'fully human' and should not be treated as medical resources.  However, places like Hailsham no longer exist and cloned organ donors now have soulless existences in ‘vast government homes’. 

Shortly after this meeting, Tommy completes his donations and Kathy prepares to become a donor herself.