Sarah Polley, a canadian actress best known for The Sweet Hereafter and the remake of Dawn of the Dead, is twenty-eight. I mention her age because Polley makes a miraculous debut as director and screenwriter of Away From Her by telling the story of a fifty-year marriage attacked by an unseen enemy: memory loss. Fiona (the luminous, legendary Julie Christie) starts fading with small things, like putting a frying pan in the fridge. But when she forgets her way home, Fiona and her husband, Grant (the excellent Gordon Pinsent), decide on the Meadowlake nursing home. In adapting Alice Munro’s short story “The Bear Came Over the Mountain,” Polley avoids any trace of TV-movie glibness or sentiment. As Fiona grows close to Aubrey (Michael Murphy), a wheelchair-bound patient who barely speaks, and Grant takes comfort with Aubrey’s hard-edged wife, Marian (Olympia Dukakis), Polley paints a devastating portrait of what gets lost in relationships even without the presence of Alzheimer’s disease. All the acting is first-rate — Dukakis gives major dimensions to a supporting role. And Christie, a Sixties screen goddess in Darling and Doctor Zhivago, shows that her spirit and grace are eternal. She’s a beauty. So is the movie.