Never Let Me Go is set in a dystopian world in which human clones are created so that they can donate their organs as young adults. The novel follows the life story of Kathy, a clone who is raised at a boarding school for future “donors.” It is related in flashback: Kathy is now thirty-one and about to start her first donations. For the past eleven years, she has worked as a “carer,” a nurse and companion to clones who are in between donations.
Kathy reminisces about her time at Hailsham. Her two most important friends were Ruth, a charismatic but manipulative and dishonest “queen bee,” and Tommy, a kind boy with a bad temper who is disliked by the other students. Kathy relates a number of anecdotes about how her relationships with Ruth and Tommy change over time.
Hailsham places a great emphasis on art, writing, and other forms of “creativity.” A mysterious woman named Madame comes periodically to take the students’ best artwork away to an off-campus “Gallery.” Tommy is not particularly good at these things and never gets pieces into the Gallery, which is part of why he is ostracized. One day when he is thirteen, Miss Lucy, a teacher and guardian, informs Tommy that it is all right if he has trouble being creative because it does not matter anyway. Kathy is shocked by this.
Kathy relates several anecdotes about Ruth’s pathological lying. At one point, Ruth pretends to be talented at chess when she does not actually know how to play. At another, she pretends that a pencil case was a gift from her favorite teacher when in fact she bought it for herself. Nevertheless, Kathy becomes good friends with her, and when she loses her favorite cassette tape––which features a song called “Never Let Me Go,”––Ruth tries to help her find it.
One day, Miss Lucy tries to explain to the students about how tragic and difficult their lives will be once they become donors. However, the students are unable to process the information. Around age sixteen, Tommy and Ruth begin dating each other. Kathy is slightly jealous but tries to hide her feelings for Tommy. A few months after Tommy and Ruth get together, the students graduate from Hailsham and go to live at the Cottage, a more relaxed holding facility where the students are free to drive and otherwise act as they wish.
At the Cottages, Ruth becomes fixated on impressing the older students, or ‘veterans.’ Two of these veterans, Chrissie and Rodney, take Kathy, Ruth, and Tommy on a trip to Norfolk because Rodney believes he has found Ruth’s “original,” the person from whom she was cloned. On the trip, Chrissie and Rodney confront the younger students about a rumor that if two Hailsham students are truly in love, they can get their donations deferred so they might have a few years together. No one has heard of this program, but Ruth pretends that she knows all about it.
Tommy and Kathy split from the rest of the group. At Tommy’s suggestion, they look in secondhand stores for the favorite music tape that Kathy lost so many years ago. They find it and have an emotional moment together. Ruth begins to notice the growing affection between Kathy and Tommy, and does what she can to sabotage the budding relationship. She tells Tommy that Kathy dislikes his drawings, and tells Kathy that Tommy could never fall in love with someone who has had casual sex, as Kathy has.
Kathy is saddened by the situation, so she voluntarily leaves the Cottages to begin her carer training. Several years later, rumors begin to circulate that Hailsham has closed. One day, Kathy encounters an old friend from Hailsham who informs her that Ruth has begun her donations and is doing poorly. Despite their tumultuous relationship when they were young, Kathy volunteers to become Ruth’s carer.
Ruth asks Kathy to take her to see an abandoned boat several hours away. Kathy agrees, and they stop to visit Tommy, who has also begun his donations. Tommy’s “recovery center” is near the boat, and Kathy suspects this is why Ruth wanted to make the trip. When the trio is back together, Ruth apologizes for keeping Kathy and Tommy apart. She encourages them to apply for a deferral so they can have a few years together, and gives them the address of Madame, whom she believes will be able to help.
Shortly after this, Ruth dies. Kathy becomes Tommy’s carer. By this point, Tommy has made three organ donations and is approaching his fourth, which clones generally do not survive. Kathy and Tommy go to visit Madame, who kindly tells them that the deferral program never existed. She explains that Hailsham was a “progressive” school, and that she and the other guardians were actually activists for the humane treatment of clones. The emphasis on artwork was to show the public that the clones had souls. However, the humane-treatment movement has petered out and Hailsham has lost its funding.
On the way back to the recovery center, Tommy is overcome with emotion and throws a tantrum. However, he gets past this and comes to accept that he will die soon. Because he is suffering from increasingly gruesome medical problems, he asks Kathy to stop being his carer. Kathy reluctantly agrees, and she bids farewell to Tommy as he gets ready to make his fourth donation.
Back in present day, Kathy is about to make her first donation herself. She is calm and even happy about this, because it will give her a chance to reflect on her life. She has only permitted herself one “indulgence”: a few weeks after Tommy dies, she goes to mourn him in a field in Norfolk. There, she imagines that all the things she has lost––most importantly, Tommy––will return to her.