Technology has forced the makers of horror films to get creative with their locations. It’s no longer sufficient that the victims be isolated in spooky houses or abandoned warehouses; now they have to be in places where they won’t get cell phone reception, either. And so we have “P2,” set in a parking garage. Whoopee.

P2 would be parking level 2, of course, the place where Angela (Rachel Nichols) has left her car on this fateful Christmas Eve. (No matter how often the film repeats it in tense situations, “P2” will always be a silly title.) With a stressful, undefined job at an undefined corporation based in a Manhattan high-rise, Angela hardly has time for friends or family. But after working late tonight, she is heading to New Jersey to spend the holiday with her mother and sister.

She’s the last one out of the building except for the parking garage security guard, Tom (Wes Bentley), who turns out to a) have a crush on her and b) be a psychopath. He chloroforms her. When she wakes up, she’s chained to a table in the garage’s office. It goes downhill from there, both for her and the viewer.

If you think that sounds like a pretty thin story for a 98-minute movie, you have a good point. I’m thinking of other recent films with similar stories and similarly small casts — “Vacancy,” which was just 85 minutes, and the French thriller “Them,” which was a scant 77. Both films are fast-paced and scary, in large part because they don’t waste any time. “P2” takes the opposite route, stretching things out as much as possible.

This is the first film by one Franck Khalfoun, who co-wrote it with Alexandre Aja and Gregory Levasseur, the minds behind “High Tension” and last year’s “The Hills Have Eyes” remake. Their adorable fascination with blood ‘n’ gore continues. “Yeah!” the kids seem to say. “We’re gonna make a movie with guts in it, and it will be super-scary! See if you can borrow your dad’s video camera!”

The main defect in “P2,” though, is Tom, who isn’t creepy so much as pathetic. He’s from the Norman Bates line of psychos who idolize and fear women to the point of wanting to kill them, but Wes Bentley’s screaming and ranting is (unintentionally) funny, not unnerving. If he weren’t armed, and if Angela weren’t often handcuffed, there would be no reason at all to feel intimidated by him. It’s like being menaced by Tobey Maguire.

He’s also not a very believable nutcase. Most movie psychos have a pattern of craziness. In the best films, you can even diagnose the character’s specific mental illnesses. Tom, on the other hand, is crazy in a general, random way. He can be delusional, lucid, gentle, vindictive, rational, or violent — and when he changes, it’s always because the story requires it, not because of the character’s psychosis.

My favorite part is when Angela sneaks into the office to retrieve her cell phone to call for help. She has to crawl across the desk to get it, and as she does so, she climbs over … a phone. You know, the regular desk kind that they have in offices. The kind that use telephone wires instead of cellular towers. Stupid functional telephone! she must be thinking. Get out of my way so I can get to my non-functional one! Way to go, Angie.

D (1 hr., 38 min.; R, a lot of harsh profanity, some very gruesome and very bloody violence.)