Two disturbed young siblings return home from the hospital and resume an acrimonious life with their father and stepmother in writer-director Kim Jee-woon’s horror movie, the third-largest-grossing South Korean film of 2003. In theory it’s an ambiguous ghost story, like The Turn of the Screw, that deliberately obscures the distinction between the supernatural and the imaginary, but in practice the awkward storytelling and spotty exposition reduce it to a string of rude shocksnot even the eventual denouement provides a lucid enough account of where this is all coming from. It’s roughly three parts Brian De Palma to one part Val Lewton; I would have preferred the reverse. In Korean with subtitles. 115 min. (JR)