The sequel to the low-budget blockbuster "Paranormal Activity" takes place a few months before the events of the first film.
Katie (Katie Featherston), the much put-upon leading lady in the original, has a sister living in an upscale Los Angeles suburb named Kristi (Sprague Grayden). Kristi has a new baby son, Hunter; a likable lug of a husband named Daniel (Brian Boland), who owns several fast-food joints; a teenage stepdaughter from her hubby's first marriage, Ali (Molly Ephraim); and a large, friendly dog.
As the family gets used to the new arrival, strange noises are heard late at night and when they come home from an outing, they discover the house has been trashed, even though none of their valuables have been stolen. Daniel responds by installing a security system and a network of surveillance cameras, though that doesn't stop the noises or the Latino housekeeper's insistence that spirits lurk in the home.
When Katie and her boyfriend, Micah (Micah Sloat), stop by for a visit, they discuss the strange goings-on with Kristi; the women of the house believe supernatural forces are at work, while the men find that notion ridiculous. That doesn't last long, as the spirits get noisier and angrier, especially when Ali begins doing some research on the subject, and before long the safety of the household is being threatened on several fronts, possibly due to some dirty dealings in the family's distant past.