RABBIT HOLE

John Cameron Mitchell's Rabbit Hole, which stars Nicole Kidman and Aaron Eckhart as a married couple coping with the loss of their four-year-old son, is based on the Pulitzer Prize-winning play by screenwriter David Lindsay-Abaire, and there's probably not much reason for the film to exist. Happily, though, it appears that nobody brought that to the director's or the author's attention, because as unnecessary movies go, Rabbit Hole is a mostly exemplary one - a stagey yet emotionally incisive, ultimately cathartic experience blessed with the sort of powerhouse cast that could never be assembled, in full, on a stage.