On the surface, Copshop, the new movie from director Joe Carnahan (Smokin’ Aces), looks like a standard shoot-em-up kind of action film, where blood flows easily and characters make improbable comebacks. And to be sure, Copshop is that several times over, especially starting at its midpoint. At the same time, there’s some surprising depth amid all the zinging bullets, and while Carnahan — who also co-wrote the screenplay with Kurt McLeod, based on a story by McLeod and Mark Williams — could’ve tightened up the plot and characters, there are thrills to be had. Fun yet flawed, Copshop mixes 70s action flair with present day suspense to create a fairly entertaining single-location shootout.

Con artist Teddy Murretto (Frank Grillo) is on the run in the dusty Nevada desert. Desperate to avoid whatever terrible fate he knows is coming for him, he slugs rookie cop Valerie Young (Alexis Louder) and scores a one-way ticket to an overnight holding cell. However, it isn’t long before he realizes the drunkard who was thrown in after him is none other than hitman Bob Viddick (Gerard Butler), a man who is very, very good at his job. As Valerie gets pulled into the tangled web between Teddy and Viddick, the stakes at the police station get even higher and deadlier with the arrival of psychopathic assassin Anthony Lamb (Toby Huss), who also has his eyes on taking out Teddy.

Carnahan’s desire to make a 70s action homage is clear right from the opening credits, between its bolded lettering and music, which is the theme from the 1973 Clint Eastwood movie Magnum Force. Production-wise, Carnahan has crafted a slick thriller. He and cinematographer Juan Miguel Azpiroz keep the camera moving, particularly with tracking shots that follow Teddy’s pacing in his cell. The score by Clinton Shorter adds the right amount of unease to pivotal moments, and while one might wish that Copshop made better use of the police station where virtually all of the action takes place, Carnahan choreographs an entertaining final act. Copshop doesn’t make it clear who will come out on top, making for an intriguing battle of wills between the four main characters.

Thanks to the trailer released online last month, Copshop looks like a violent all-out brawl, with relentless gunfire and brutal fist fights. That’s why it might come as surprise to some that, aside from some early flashes of motion, the movie doesn’t really kick into high gear until Huss’ Lamb shows up 50 minutes in. Before that, Copshop is largely a verbal cat-and-mouse game between just Viddick and Teddy as Valerie investigates just what brought Teddy to the police station. Carnahan tries to add some outside intrigue with a plot about a slain attorney general and a corrupt cop, but it doesn’t quite amount to anything truly satisfying. Copshop is at its best when it’s focusing on the thorny dynamics between the characters, but the first half is muddled a bit by setup. Carnahan injects some feelings of anticipation into the story, but that can’t always keep attentions focused. When Lamb arrives, then the action truly gets exciting. Though the movie itself might run out of steam by the very end, it at least offers a satisfying conclusion to the bloody ordeal.

Butler and Grillo both commit to their tough guy characters, though it’s Butler who comes away with some unexpected humanity in Viddick’s characterization at the end. Copshop doesn’t spend a significant time adding layers to the characters, only offering occasional glimpses at what lies inside for those like Viddick, Valerie, and Teddy. As Valerie, Louder is a force to be reckoned with. Adopting a perfectly steely gaze and a determined scowl, she makes Valerie the only person audiences might end up rooting for. As for Huss, he seems to be having a ball as the sadistic Lamb, and he’ll likely pull some awkward laughter out of viewers. Huss’ unhinged performance is a highlight of the movie, which makes it all the more disappointing that it takes so long for him to arrive.

Copshop appears to be one thing on the surface, but ends up containing some surprising depths. They don’t entirely erase the movie’s flaws, whether it be pacing or an unnecessarily complicated story. When it focuses on the main plot of a man being hunted by dangerous killers and the woman trying to work out who to trust, it’s an entertaining thrill ride that perhaps could’ve been even wilder, but suits just fine. Copshop won’t be for everyone, but those looking for some old-fashioned gun-slinging hijinks will get some enjoyment out of it.