When first we meet nine-year-old Joshua Cairn (Jacob Kogan), there's not an ounce of rambunctiousness in him. He's a superior pianist, natch, and brainiac to boot, with his hair perfectly coiffed and his skin a pale shade of corpse. Joshua is more a parody of a pint-size horror-show monster than the real deal, more lonely than loathsome — the kind of kid who asks his daddy (a toned-down Sam Rockwell) if he loves him because he's genuinely afraid the old man is losing interest. And then comes the beautiful baby girl, a little sister ready to command the attention Joshua expects and demands and craves. Joshua's mother (Vera Farmiga) can't take her wide eyes off the newborn; Dad can't put her down. So Joshua is left all alone — to dissect his plush toys, mummify his hamster, and maybe kill the family dog. But what parent hasn't said, "That kid's gonna drive me crazy"? What parent hasn't looked at their child at some point and been hit with the sudden, terrifying realization that within the apparently angelic lurks the potentially demonic? Children are remarkably manipulative at an early age, and Joshua is merely a big-screen variation on the real-life version — a kid who takes great pleasure in freaking out his folks.