From the promotional materials:
In his highly acclaimed novel Never Let Me Go, Kazuo Ishiguro (The Remains of the Day) created a remarkable story of love, loss and hidden truths. In it he posed the fundamental question: What makes us human? Now director Mark Romanek (ONE HOUR PHOTO), writer Alex Garland and DNA Films bring Ishiguro’s hauntingly poignant and emotional story to the screen. Kathy (Oscar® nominee Carey Mulligan, AN EDUCATION), Tommy (Andrew Garfield, BOY A, RED RIDING) and Ruth (Oscar® nominee Keira Knightley, PRIDE & PREJUDICE, ATONEMENT) live in a world and a time that feel familiar to us, but are not quite like anything we know. They spend their childhood at Hailsham, a seemingly idyllic English boarding school. When they leave the shelter of the school and the terrible truth of their fate is revealed to them, they must also confront the deep feelings of love, jealousy and betrayal that threaten to pull them apart.
See also: Book Review: Never Let Me Go