There is an old saying in theater: if there is a loaded pistol on stage in the first act, it had better be fired in the last. The adage has become shorthand for the need to manage the tenuous relationship of suspense and payoff.

The problem with “Paranormal Activity 4” is that it is all gun and no bang.

While this fourth installment of the wildly popular franchise manages to introduce its gun with mild success, it takes far too long to get to the actual payoff. And even worse, when the trigger is at last pulled, the ever anticipated bang is actually more of an embarrassing poof.

The film continues “Paranormal Activity’s” profitable shtick with its found-footage style, predictable plot formula and demons who show their presence mostly by messing with people’s furniture. But this installment caters to its core demographic – teens hoping to scream – by focusing on pretty fifteen-year-old suburbanite Alex.

Along with her boyfriend, Ben, Alex begins to investigate her dour-faced neighbor, Robbie, after the tot’s mother (Katie from the first two installments) is hospitalized. Complying with horror movie logic, he ends up staying with Alex’s family, and weird things follow him across the street.

The two teenage sleuths decide to set up 24-hour surveillance of the house by installing continuous recording programs on laptops scattered throughout the house – even the six-year-old’s room (seems legit, right?).

The resulting footage makes up the bulk of “Paranormal Activity 4,” but unfortunately, a ridiculous amount of time is spent switching between camera shots of empty rooms. Audiences are constantly doing a mental “no ghost in here” checklist that, needless to say, gets boring really quickly.

While creepy kids are normally stale horror fodder, Robbie is actually one of the film’s few successes. The character is less demon-baby and more like that creepy kid you knew in real-life kindergarten – the one who tells you he can read thoughts or that he bleeds blue blood (which, by the way, were both said by real kids I know).

Robbie is a dweeby little creep. He has a mushroom cut, wears sweatpant-gauchos and rocks the ever-alluring socks and sandals combo. Thankfully, Robbie doesn’t utter threats filled with demonic weight that far too many horror movie kids use. Instead, he has an awkward, off-hand delivery that makes him sound like a real child, just … off.

Robbie fits the film’s mockumentary style, and his believability has the potential to provide more scares than the rest of the movie manages to deliver. Nevertheless, the few moments that do elicit jumps and gasps are mostly Robbie’s strange little face popping up in places it shouldn’t.

The one other highlight in the otherwise lackluster film is the humor provided by Alex’s bro-ishly charming boyfriend, Ben. The two teens have a flirtatious dynamic that creates a few undeniably enjoyable moments. But while their cute repartee is fun, it’s just not enough to make up for the lack of “activity” that frustratingly comprises “Paranormal Activity 4.”

Beyond the outrageous amount of weak scares (i.e. chairs moving, repetitive shots of the teens freaking out and countless shots of a Microsoft Kinect, one of the movie’s lone new features) and the dubious idea that people will continue to hold their recording devices when face-to-face with a demon, there is the unavoidable problem of the ending.

To call it disappointing would be generous. Everyone in my theater seemed to have the same sort of “that’s it?” reaction. A few people were even openly laughing out loud.

Much like the other installments, the entire film builds ever so slowly toward some sort of epic conclusion, but it never seems to fully arrive. Audiences are instead left with what feels like a waste of time and money. The movie never makes use of the few interesting ideas it manages to wring out of its derivative concept, and it fails to provide even the cheap thrills of its predecessors.

“Paranormal Activity 4” commits the cardinal sin of horror – it’s just not that scary. Hopefully, the already-planned fifth installment will repent for this series’ continually diminishing returns.