What a good short film “Salvage” would have made, and what a bad long film it is. It’s a low-budget, low-impact, low-quality horror flick with a cool idea that simply doesn’t withstand being stretched over 90 minutes. Chop it down to about 20 and you’d have something.

It begins with Claire (Lauren Currie Lewis), a 19-year-old college student, leaving her graveyard shift at a convenience store and waiting for her boyfriend, Jimmy, to pick her up. But arriving instead, in Jimmy’s truck, is Duke (Chris Ferry), a friend of Jimmy’s from the salvage yard where he works. Allegedly, Jimmy asked Duke to give Claire a ride home.

Scary-movie things happen at that point, and then Claire wakes up. She’s back at the convenience store, apparently having dozed off on the job. The whole thing was a dream. OR WAS IT?!?!?!??!

Back in reality now, the film spins its wheels for a good long time. Claire’s mom (Maureen Olander) is behaving strangely in the basement. Jimmy (Cody Darbe) says he had a sexy dream about Claire and a friend of hers. Claire experiences deja vu in class and sees the killer from her dream stalking her elsewhere. OR DOES SHE?!?!?!?!?!??!

We realize early on that very little, if any, of what’s happening is real, that most of it is in Claire’s head. When the film goes into “Groundhog Day” mode (albeit with variations each time Claire is attacked), the relevant question becomes: Why should we be scared for Claire when we know she’s just going to wake up any minute anyway?

I also wonder: How many times can one character back away slowly from something while shaking her head in horror and saying, “No … no …”? It seems like half the shots in the film are of Claire doing that. The other half are of her walking slowly down stairs or around corners, saying, “Hello? Is someone there?”

Jeff and Josh Crook, the brothers who wrote and directed “Salvage,” have made three little-seen films before this one, all available on DVD. There are encouraging reviews of those movies on the Internet. “Salvage,” the Crooks’ first foray into horror, is likely a downturn in quality for them. It’s a film that will probably nowhere and do nothing.

D (1 hr., 30 min.; Not Rated, probably R for a lot of harsh profanity, some graphic violence.)