Never Let Me Go is set in alternative history and centres on Kathy, Ruth, and Tommy, portrayed by Carey Mulligan, Keira Knightley, and Andrew Garfield, respectively, who become entangled in a love triangle.

Mulligan was cast in the role after Peter Rice, the head of the company financing the film, recommended her by text message while watching her performance in An Education.

The teachers, called guardians, encourage students to be health-conscious and create artwork, the best of which is accepted into The Gallery run by the mysterious Madame; they have little other contact with the world beyond the school's fences.

Seven years later, Kathy, Ruth, and Tommy, now young adults, are rehoused in the Cottages on a farm; they are allowed to drive away on day trips, but they remain reclusive, lacking social skills and resigned to their fate.

Tommy, still partnered with Ruth, is convinced that The Gallery serves as verification for deferrals since artwork reveals the soul and laments his lack of creativity.

Director Mark Romanek has highlighted that everyone must clarify a relationship with their own mortality: either go against it or find a way around it, as the character Tommy does, the clones' acquiescence echoing aspects of original author Ishiguro's British Japanese background.

[9] Director Mark Romanek was originally attached to The Wolfman, but when he was dropped from that production for an unknown reason, he accepted the offer to work on Never Let Me Go.

"[8] The Seattle Times observed that the project was "something of a departure" for the novelist, noting that it merges Ishiguro's signature "elegant prose with a decidedly science-fiction theme".

"Garland, who has explored science fiction themes in his previous work, was a sounding board for ideas for the novel and an early reader of the book.

[3] Carey Mulligan plays the narrator, Kathy, an introverted, observant character who projects both innocence and knowingness and who over the course of the story develops from a passionate, optimistic child to a wise and accepting young woman.

Romanek told The Los Angeles Times that he originally was having difficulty finding the right actress to play Kathy; a tight filming deadline loomed before Mulligan's casting.

[13] Andrew Garfield was cast as Tommy, a well-meaning, rather dim young person who struggles to find a place in an environment which values imagination and creativity above all.

[20] Sally Hawkins, who co-starred with Mulligan in An Education, had a supporting role as Miss Lucy, a teacher at an isolated English boarding school where the students slowly become aware that they are feared by people in the outside world.

[22] Richard was cast as the administrator, known as Madame, who is conducting a project to analyse the students' characters and psychologies, which has been compared to treating them as if they were subjects in an experiment.

A large property on the Bexhill-on-Sea seafront was used on 12 and 13 May 2009 to act as the exterior for the residence of Madame, where Tommy and Kathy go to apply for a deferral.

[31] Portman employed a smaller orchestra consisting of 48 players, and used instruments such as piano, strings and harp, with solos for violin and cello, and recorded the score within four months.

[46] To promote the film, Mulligan appeared at movie screenings, including at the Landmark Theatres and AMC Loews Lincoln Square.

He believed its reviews were "likely to be split between those who consider the film a bleak masterpiece and others who find it straining so mightily for aesthetic perfection that it fails to provide a gripping narrative.

[1] According to a news piece published by the Los Angeles Times on 21 October, by its fifth week of release, the film was an "undeniable disappointment" commercially.

The publication noted that when its release widened to over 200 theatres the previous weekend its per-theatre average was so low that its distributor decided to cut its screens in the succeeding weeks.

[54] Based on answers from film experts and executives for Fox Searchlight, there were five factors to why the film commercially disappointed: its timing, airing too early in the year when lighter summer fare is still popular; a novel that is particularly difficult to adapt; mixed reviews from critics; its depressing tone; and its lack of appeal to male viewers.

The website's critical consensus reads, "Mark Romanek has delivered a graceful adaptation that captures the spirit of the Ishiguro novel—which will be precisely the problem for some viewers.

[36] Cleveland Magazine's Clint O'Connor strongly approved the acting performance of Garfield,[58] and Eric Kohn from IndieWire praised Garland’s script and Kimmel’s photography.

[59] Chris Knight of the National Post wrote that the film was able to capture the wistfulness and the unpredictable tone of Ishiguro's novel, but added that it "spills the beans much sooner".

[60] Mark Jenkins of NPR called Never Let Me Go a "remarkably successful adaptation" of Ishiguro's book, but acknowledged that Romanek and Garland "do make a few missteps", which were mostly the result of the limitations imposed by turning the novel's contents into a film.

[19] Slant writer Ed Gonzalez gave the film a two-out-of-four-star rating, saying the characters' actions do not feel "appropriately warped" while the interactions between the teachers and students is not "at all rife with the what-are-they-thinking-about-us mystery of the book".

[64] Tom Preston from The Guardian described Mulligan and Garfield's acting as solid, while commenting that Knightley's emotional performances are occasionally jarring.

He said that the film does work on a "suspense level", due to Romanek's creating a "quiet, leisurely pace that would not be out of place in a yoga class".

[69] Scott Bowles, writing for USA Today, gave the film a negative review, declaring "never was a movie so bleak and empty".

[70] New York Times journalist Manohla Dargis said that the film presented "the aspect of a tasteful shocker" because its "cruelty is done so prettily and with such caution that the sting remains light".