Never Let Me Go, directed by Mark Romanek, known for his lush music video style (see: Madonna's "Bedtime Story" and Fiona Apple's "Criminal"), is not the sort of film you can go into and not come out of the other side somewhat changed--specifically, a greater number of tears streaming down your visage where once there were none. Based on Kazuo Ishiguro's 2005 novel, Alex Garland (who wrote 1996's The Beach) adapted the script into a sweeping emotional vista of longing, regret and helplessness.
Like so many other tragic tales, Never Let Me Go centers around a love triangle. Three friends relegated to an isolated boarding school called Hailsham in 1978, Kathy (Carey Mulligan), Ruth (Keira Knightley) and Tommy (Andrew Garfield), are blissfully unaware of their sole purpose in life: to be donors for others. Set in an English dystopia (as I've always said, Britain is the go-to for dystopias--likely thanks to George Orwell), the average human lifespan has been expanded to at least one hundred years, in part due to the sect of the human race responsible for donating their organs.
It isn't until a new teacher at Hailsham, Miss Lucy (Sally Hawkins), informs them that their sole purpose is to give extended life to others that the dynamic of the trio starts to shift. After that day, Ruth, who is well aware of Tommy and Kathy's unfulfilled love for one another, makes a move on Tommy. Echoing tones of Sandra Goldbacher's Me Without You, the film then shifts to 1985, when the trio is transferred from Hailsham to The Cottages. By now, Tommy and Ruth have been together for years, though it's clear Tommy's interest in Kathy hasn't waned. Ruth's jealousy over this makes her hostile toward Kathy, who begins distancing herself from both Tommy and Ruth at this time. With the option to become what is called a "carer," Kathy is able to delay her first donation by several years. It's another ten before she sees Tommy and Ruth again after they depart from The Cottages.
The next time Kathy sees her female rival, Ruth has completed two donations and is going on to her third. When a donor has "completed," this is a polite way of saying he or she has kicked the bucket. Ruth, overtly humbled and wizened by her experiences in the operating room, requests that she and Kathy go on a trip together--with Tommy. Because Ruth has had time to reflect on the turn of events at Hailsham and The Cottages, she confesses to Kathy and Tommy that she knows keeping them apart was the worst thing she ever did, but it was her way of feeling like she wouldn't be the one to end up alone. To remedy her mistake, she gives them the address of one of the headmistresses of Hailsham, Madame Mary Claude (Natalie Richard), who is rumored to give couples "truly in love" a deferral on their donations.
The bittersweet conclusion finds Kathy alone after experiencing the brief bliss of finally being with Tommy as they were intended to be. The disappointment of Madame Mary Claude's rejection is compounded by her telling them that they're, in essence, lesser than human. But Kathy knows better, remarking, "In the end, we all 'complete'" and "None of us understand what we've gone through, or feel that we've had enough time." The differences between "donors" and "normal humans" are, thus, not that vast.