The severe pixie hairdo that Nicole Kidman wears in Birth isn't meant to be flattering; it's the Rosemary's Baby martyr cut. Kidman plays one of those pale movie waifs whose spouse died a while ago (in this case, 10 years) but who is still Mourning His Loss. When a 10-year-old boy (Cameron Bright) with the face of an angelic owl shows up and claims to be her late husband not the spirit of her late husband, but the dude himself she's doubtful at first, but before long she begins to believe.
The notion that Kidman might be married to a prepubescent tyke presents, you might say, a few minor practical problems. Her fiancé (Danny Huston) is a tad upset, and so are her relatives, led by a feisty Lauren Bacall, whose tart skepticism slices through the movie's is-it-supernatural-or-is-it-Memorex? glaze. In a series of cavernous old-money New York apartments, the family gathers to question the boy about things that only Kidman's husband would have knowledge of. The trouble is, the script is so cloddish in its ambiguity that their questioning never pushes hard enough to establish whether the boy could have learned what he knows through outside means.
We're meant to stare at Cameron Bright, with his spooky inscrutability, and think, ''What if...?'' All I could think was, What in God's name do the filmmakers think they're doing? When Kidman slithers into a bathtub with her young ''husband,'' the scene, in its soft-pedaled way, is the definition of exploitation: It appears to have been cooked up for no other purpose than to conjure creepy child-porn overtones. This is the second film directed by Jonathan Glazer, whose first was the electrifying Sexy Beast, and I hope that we'll one day look back at Birth as a movie he needed to get out of his system before he returned to the art of authentic storytelling.