Is it a plot spoiler to reveal that the new film “Never Let Me Go” is about cloning? Sorry. But the beautiful novel has become a reasonably good film, according to the critics. Booker Prize winner Kazuo Ishiguro (author of Remains of the Day) wrote his novel about children raised in a classic English boarding school in 2005 to much acclaim. The reader gradually learns that they are clones destined to serve as organ donors. The book resists the temptation to exploit cloning as a lurid scifi potboiler and focuses on the characters' wistful, frustrated desire for love. It has a haunting charm and ravishing prose. Has anyone seen the film yet?