"This is the story you get!" So, occasionally, go the timeless, peremptory final words between parent and child at story time. In this case, the words are exchnaged between Joy (Brie Larson) and Jack Newsome (Jacob Tremplay), who looks rather like a Jill at first glance. As it happens, there's an explanation for the boy's feminine appearance, beyond his soft features. Jack possesses hair that probably has never had the benefit of good shampoo or a pair of scissors during his five years of life. If you don't know the premise of Room before you sit down in the movie theater, if you haven't seen the film's typical here's-the-entire-plot-in-two-minutes-trailer, you quickly realize that "Room," the compact space in which Jack lives with his mother, is the only home the boy has known. To know that Jack is newly five, as we do by the humble birthday cake (which Jack initially rejects due to its lack of candles) that is baked early in