Alexis, Val, and Bev are three young women that you probably wouldn’t expect to see driving to a seedy bar in the middle of nowhere to attend a heavy metal concert in the late-1980s. Though they look the part, dressed in black leather, spikes, big hair, and loud makeup, there’s something about these three girls that doesn’t quite click, as they discuss the newest teen magazine, snacks, and makeup tips. Director Marc Meyers takes those characters and inserts them into the middle of a film that is also suffering from an identity crisis. “We Summon the Darkness” wraps itself in all the ingredients of a grindhouse feature but never quite pulls it off in a truly convincing manner. But it sure is a fun attempt.

Without getting too bogged down in the twists and turns of the plot, “We Summon the Darkness” follows the story of three young women who pick up three male metalheads at a concert and invite them back to their house for a night of partying. But as mentioned, it’s somewhat obvious that Alexis (Alexandra Daddario), Val (Maddie Hasson), and Bev (Amy Forsyth) aren’t all they appear to be, as the three unsuspecting guys become the lastest potential sacrifices of a Satanic cult that has been going around and killing people all around the country.

It’s clear from the moment the second act begins, when the audience is allowed to see Alexis, Val, and Bev without their facades, that director Meyers is positioning “We Summon the Darkness” as a refreshing horror callback to the era gleeful excess of the ‘70s and ‘80s grindhouse films. The actors and dialogue are all over-the-top and campy. The story pushes plenty of taboo hot buttons with commentaries on religion and corruption. And the deaths are all supposed to elicit equal amounts of shock, horror, and verve. Unfortunately, just when the film almost convinces you that it could be a modern grindhouse delight, the film pulls a punch—or in this case, drops a boat motor—and you realize that “We Summon the Darkness” is just a passable, if not fully enjoyable, slasher film with far too much untapped potential.

And there’s no aspect of “We Summon the Darkness” that illustrates this shortcoming more than the acting. Alexandra Daddario is, without a doubt, one of the most beautiful women working in Hollywood. And seeing her as a possibly-Satanic metalhead is jarring at first. However, when her true psychotic nature is revealed, Daddario fully embraces the opportunity to chew up the scenery and deliver a performance that you can’t help but adore. Her eye-acting alone is worth the price of admission, as she uses her piercing baby blues to steal your attention and utterly convince you she’s the type of girl that would slit your throat and laugh doing it. She’s joined by Hasson, who is positioned as the sex-crazed member of the girl gang but largely subverts your expectations becoming the much-appreciated comic relief, given some of the very best lines in the entire film. The rest of the cast is also doing its best, as the various actors ensure that each character adds a wrinkle to the horror archetypes they inhabit.

But when you have a cast committing so fully to the campy nature of the story and the extremes of horror acting, it’s the filmmaker’s job to give them the tools to succeed. Unfortunately, that’s where Meyers and his scriptwriter Alan Trezza come up frustratingly short. Though the dialogue is often fun, punchy, and silly (in all the right ways), the plotting is needlessly convoluted and the action is mundane and anti-climactic. Characters carry huge butcher knives only to make one stab or a simple slash. Guns are used sparingly, and when they are, it’s horribly uninteresting—blood spatter is barely ever required. The two worst offenders are the constant teasing of a boat motor being used as a chainsaw, with no real payoff, and the lighting of a character’s hair on fire, with no burnt remains to be shown. In a horror film, particularly an ‘80s-set Satanic slasher, audiences expect the murders to be moments to cheer and squeal with psychopathic joy. Instead, “We Summon the Darkness” gives you killings that barely warrant an R-rating and aren’t dissimilar from what you might find in a modern PG-13 teen horror film.

That being said, the charisma from the leads and the ridiculousness of the story do mask a lot of the shortcomings. Just when you’re ready to give up on “We Summon the Darkness,” something will happen that will bring the smile back to your face and give you hope that the potential will be fulfilled. Though it may be an unimaginative slasher hiding in grindhouse clothing, Daddario, Hasson, and the rest of the cast conjure up enough craziness to make the finished film way more enjoyable than pregaming a lukewarm PBR right before a metal show. [B-]