How do you recover from the death of a child? The movie 'Rabbit Hole' eloquently posits the only correct answer to that question: You don't. Based on David Lindsay-Abaire's acclaimed 2006 play of the same name, 'Rabbit Hole' focuses on a grieving couple eight months after their young son was killed by a car while chasing his dog into the street. What on the surface seems to possess all the melodrama and photogenic suffering of a banal prime-time weepie instead becomes a lucid, tough, deeply sensitive examination of emotional fortitude. It's important for viewers to know that it's okay to laugh during 'Rabbit Hole.' Thanks to Lindsay-Abaire's mastery of difficult tonal shifts and John Cameron Mitchell's alert, nimble direction, laughs and tears co-exist, if not comfortably, at least recognizably as equally necessary to surviving life's most devastating moments. In Nicole Kidman and Aaron Eckhart, Mitchell has found actors who gracefully pull off that psychological high-wire act as Becca and Howie, an attractive, prosperous couple who have reached the point in their mourning where most of their friends and neighbors think it's time to be moving on. Howie tries to do this by attending support-group meetings and contemplating another child. Becca cooks compulsively, repels the efforts of friends to get together and goes about daily life with crisp matter-of-factness, even when it comes to removing their son's drawings from the refrigerator. Becca reserves her cruelest barbs for her mother, Nat (Dianne Wiest), who lost a grown son to drug addiction but whose attempts at empathy Becca resents as unearned comparisons. (Sandra Oh and Tammy Blanchard, as a support group member and Becca's sister, respectively, provide welcome comic relief for the film's most discomfiting encounters.) Becca eventually discovers solace in the most surprising place imaginable, but 'Rabbit Hole' resists facile catharsis or easy equivalencies. Thanks in large part to Kidman's refusal to soften her character's most fascinating sharp edges, as well as Mitchell's superb command of the material, 'Rabbit Hole' gives the lie to such comforting fictions as closure and transcendence. As Wiest suggests in her character's moving soliloquy, sometimes the best thing to do with feelings isn't to 'process' or 'work through' them, but simply to feel them. 'Hanging in there' can often seem like a meaningless cliche, but in 'Rabbit Hole' the phrase takes on newfound meaning as perhaps the hardest, most heroic thing in the world to do. PG-13. Contains mature thematic material, drug use and profanity. 92 minutes. 