We know that new, last-minute-replacement babysitter Anna (Sarah Bolger: My All American) is going to be a nightmare from the moment she shows up at the Thompson home. We know because we’ve seen what happened before she arrived. But as far as the Thompsons can see, she is a godsend: Joyce (Susan Pourfar: Alex of Venice) and Dan (Chris Beetem) get to head out for their anniversary dinner secure in the knowledge that the kids are in teenage-girl hands that come highly recommended, and 11-year-old Jake (Joshua Rush: Mr. Peabody & Sherman), 9-year-old Sally (Carly Adams), and 4-year-old Christopher (Thomas Bair) soon see that Anna is gonna let them get away with stuff that would freak out Mom and Dad. But soon Anna’s, er, leniency descends into the reckless, and then the sinister… and this slow-burn twist on the home-invasion story becomes a thing of unusual — and unusually elegant — suspense. Alas, though first-time feature director Michael Thelin (who wrote the script with fellow first-timer Rich Herbeck) elevates genre expectations by shaping a creepily classy atmosphere of out-of-left-field menace and building dread, where Emelie eventually ends up is the stuff of pure hoary cliché… and one that sits uneasily with its setup. Anna’s secret motives don’t quite match up with the things she’s done, but even if they did, she still represents a hackneyed take on womanhood that did not require a revisit. If only Thelin had lavished as much care and thought on his story as he did on the way he presents it.