Paranormal Activity came out of nowhere. It cost almost nothing to make, and proceeded to make over $100 million dollars. Of course there was going to be a sequel. Paranormal Activity 2 follows a lot of what made the first movie a success: the "found footage" premise, the slow build and the low rent scares. But Paranormal Activity 2's bigger budget proves that sometimes more is better.
The film follow Kristi, sister of the woman from the first film, and her husband, stepdaughter, and new baby. I don't want to give anything away, but needless to say, creepy stuff happens. This sequel doesn't try to do anything that's really all that new, but that actual works to the filmmakers advantage. They can play with our expectations from the first film, then twist them to freak us out. So it doesn't break any new ground, but it's also not the blood and guts horror that we're used to seeing these days. It's more in your head than in your face, and I really appreciated that.