It must be said that the "found footage" sub-genre of horror movies requires the audience to suspend disbelief a bit. The idea is clever - you're watching something that allegedly really happened, which gives the movie a bit of documentary-style credibility. But you have to accept that at some point in the movie, you're going to shout, "put down the darn camera!" It's surprising that the "Scream" franchise hasn't mocked this trope yet.
Either you can get past this, or you can't. If you can, the "Paranormal Activity" series should be on your must-see list. The first two movies tell the present-day stories of Kristi and Katie, two sisters whose pleasantly suburban lifestyles are ripped asunder by a sinister spectral force. In "Paranormal Activity 3," we return to 1988, where the sisters first meet the poltergeist who will terrify them and their families a few years down the road.
The movie sets the stage by showing grown-up Kristy and Katie rediscovering old videotapes from when they were children - a gift from recently departed Grandma. These tapes are later stolen in a scene all too familiar with fans of the first two films. The movie then switches to the videotapes.
Young Katie and Kristi are enjoying Katie's birthday party, and we also meet their mom Julie and her boyfriend Dennis. (Oddly, there's never any mention of the girls' biological father - where did he go . . . hmmm.) Dennis, conveniently for the movie's conceit, is a videographer, so naturally his response to every development is his life is to tape it. During the birthday video, we learn that Kristi has a close relationship with an imaginary friend, Toby.
Toby, as you might guess, turns out to be more than imaginary, and he quickly proves to be one scary, demanding guy. To avoid spoilers, that's it for the plot summary.
Directors Henry Joost and Ariel Schulman know how to make a found-footage movie. Tension builds nicely as we strain to watch a seemingly innocuous scene - are the bedsheets moving? How about the lamp? Perhaps the creepiest scenes (before the final 15 minutes, which are terrifying) come with their use of a video camera set up on an oscillating fan base so the camera slowly pans from one part of the house to another - the directors' clever use of the "that freaking thing wasn't there a few seconds ago" trick will have you looking over your own shoulder the next time you're all alone in the house and hear an unexplained noise.
For a third installment in a horror series, "Paranormal Activity 3" exceeds all expectations. A spooky film that builds to a truly frightening third act, "3" succeeds in deepening the story created by the first two installments without wearing out our interest - the filmmakers know that we're here to get scared, not to get a PhD-level understanding of Toby . . . and scare you they do. Terrific stuff.