The Monster Wore A Tank Top. Paranormal Activity 4, Reviewed.

1. Like Grierson, I'm a sucker for the Paranormal Activity films. I don't care that their stories don't make sense, that apparently there's some sort of mythology tying everything together behind them, that no one ever, ever turns that goddamned camera off. These movies work not as movies—they're barely movies at all—but simply as brutally efficient scare machines. The fact is, if you point a camera at something for 30 seconds, and at the end of that 30 seconds something JUMPS out of the side of the frame, I'm gonna leap out of my seat. It happens every time, and it's going to happen every time, until they make Paranormal Activity 49 and every shock-cut is accompanied by me spilling my colostomy bag. These movies work, even when they don't.

2. All that said, Paranormal Activity 4 is definitely the worst of the series, particularly disappointing because it comes on the heels of the best one. (It's directed by the same people, the talented douchebags who brought us the bullshit ) It's the first film of the series that doesn't seem to have any new ideas to scare us; it uses the same old techniques with the same old rhythms and the same old tropes. As established: It still works. But that doesn't mean it's not still a little tiresome.

3. The third film went back in time to the '80s, when we saw the two sisters ostensibly at the center of this story as children. ( Some people care about the backstory and the history of some sort of demonic possession at the heart of the series. I, and I suspect you, couldn't care less.) Here in the fourth installment, we're back in the "present," as the boy abducted in the second film ends up moving next door to a well-to-do Nevada family and, particularly, a teenage girl obsessed with Skype. Though, oddly, the movie never mentions Skype (or even iChat) by name. Everyone does make sure to drink Diet Pepsi and other PepsiCo beverages, however.

4. The main innovation in the third film was a camera attached to an oscillating fan. The viewer would look out over an empty room; the camera would move a few feet to the left and then come back to something terrifying now in the room. (That, in particular, had me crawling around my seat.) The directors try another new thing this time, but it doesn't work nearly as well. Apparently there's a setting on the Xbox Kinect that turns a darkened living room into a black-light party, sorta like having night-vision goggles. ( Here's what it looks like.) This isn't close to a compelling device, and, in fact, it gets in the way most of the time. Instead of the mystery of the known, we spend half our time trying to figure out who in the hell we're supposed to be looking at. The downgrade from the oscillating fan is considerable.

5. But the real issue with Paranormal Activity 4 is that nothing all that interesting happens—at least nothing we haven't seen before. At last, the series is repeating itself. It also doesn't help that the film goes back to having Katie, the tormented yuppie from the first film (played by Katie Featherston), as the spooky monster. (She was mostly absent from the third film.) I mean no offense to Featherston here, but, well, Jason Voorhees she is not. She is intended to be this ominous, evil presence, but mostly I found myself just wanting to do something with her hair. This series is just another monster series at this point. Except the monster is a 30-year-old woman in a tank top. It's a new experience in terror!

Grade: C+.

Grierson & Leitch is a regular column about the movies. Follow us on Twitter, @griersonleitch.