It’s insidious how we’ve been trained to concede that the ascendancy of badass action babes has been a boon to female-driven movies. As if all driving a movie really requires is keeping one shiny mid-calf boot pressed firmly on the gas. As if physical toughness, usually of a sort that defies physics anyway, should be the end all. On this front, maybe action movies can’t be helped. Horror, on the other hand, still has great possibilities, as we learn from Australian writer-director Jennifer Kent’s resounding debut. A weary, widowed single mom (Essie Davis), fending off some deeply shady bogeyman who seems to have sprung straight from the maybe-damaged mind of her own unruly first-grader (Noah Wiseman), or from her own? That takes real toughness: the human kind. Kent has a good handle on tried-and-true suspense techniques, well articulated creepouts, and sardonic humor, but her coup is characterization. Faced with a home (and mind) invasion by a sinister children’s book, this heroine, neither hapless and soulless nor just another uncomplicated ass-kicker, is bereaved, exhausted, at the end of her rope, and summoning her last resources, some of which turn out to be ferocious. At times she seems like both of the parents from The Shining rolled into one. In other words, there are legitimate terrors here — legitimate because, as any bleary-eyed parent will verify, they come from a real and terrible place. It’s to the filmmaker’s credit, and to Davis and Wiseman’s, that even under extreme circumstances, the mother-child dynamics just seem so true. And for those who do enjoy at least some defiance of natural laws, The Babadook has some of that too.