This indie shocker starts strong but doesn't know how to leverage its slick premise.

Dumb and horror go together like peas and carrots, to paraphrase a Gumpian prophet.

Half the fun of watching horror movies is mentally screaming for the heroes to do anything besides what they’re actually doing. That crowd participation element makes the genre pop.

It may not be “cinema,” but it’s a rollicking time at the movies.

You can only play the Dumb Card so much, though. “The Shed” is all Dumb Cards and no aces … or even a pair of Threes. “The Shed” arrives with a neat premise but has little idea what to do with it.

Stan (Jay Jay Warren) lives with his alcoholic grandpa in a quaint small town. Stan and his chum Dommer (Cody Kostro) are frequently targeted by the school bullies, even if all these high schoolers look well into their 20s.

So when Stan discovers something sinister lurking in the shed outside his home, it seems like his life just went from bad to God awful.

Only not everyone sees it that way.

The film’s trailer suggests a horror yarn where the bullies get what’s coming to them at long last. Vampire films come and go, but given the culture’s keen interest in bullying the twist arrives right on schedule. If only the film cared more about that concept, or engaging characters, for that matter.

FAST FACT: “The Shed” director Frank Sabatella says his film’s inspiration came partly from ’80s horror classics like “The Lost Boys,” “Near Dark” and “Fright Night.”

The Warren-Kostro bro bond is so toxic we never invest in their revenge plans. Blame a pedestrian script all but devoid of humor. A film like “The Shed” could have gone a different route, playing up the genre tropes with a wink and a smile.

Hey, we know this is ridiculous, but come along for the ride, why don’tcha? Instead, it’s stone cold sober, and that makes its flaws all the more iridescent.

Siobhan Fallon Hogan, light years from her brief stint on “Saturday Night Live,” overacts as the nosy Sheriff who suspects there’s more than old paint cans in Stan’s shed.

RELATED: Here’s Why We Love Horror Movies

Writer/director Frank Sabatella builds some apprehension around the titular shed, especially in the film’s first half.

Tease, don’t show, they say in horror circles, and Sabatella smartly keeps the vampire out of sight for as long as possible. That turns Stan’s shed into something mysterious despite its modest trappings.

At some point the action has to escape that confined space, and when it does the film collapses upon itself.

Warren doesn’t come close to elevating the material. It’s hard to tell who’s to blame for his one-note turn, a lack of direction or poor artistic choices. Either way, he’s sullen without gaining our sympathy, and the movie suffers greatly because of it.

Horror fans may snack on the lo-fi practical effects, but there aren’t enough kills here to merit their attention. “The Shed” even trots out a double cheap scare dream sequence, taking us back to the worst horror tics of the ’80s.

“The Shed” scores with a fiercely original premise and a whiff of social commentary. Both eventually give way to the worst feeling an indie thriller can deliver:

Is it over yet?

HiT or Miss: Indie horror can be a genre fan’s salvation, or it can leave them frustrated to the core. “The Shed” steers audiences firmly into the latter camp.