Execution always comes before concept, except for when it doesn’t. We’d all love to consistently land on the left brain side of the binary, cogently assessing the content of a package rather than its spruced-up labeling, but sometimes that casing is just too enticing. The elevator pitch for writer/director Michael Shanks’ debut feature, Together, is simply unassailable, to the point where studio money and recognizable talent flocked to it like flies to a light. Locating a premise that’s both inspired and sturdy all but ensures a baseline of quality, and Neon must have known it was playing with intellectual house money when it acquired the film out of Sundance earlier this year. Proper scaffolding goes a long way to paving over occasional misgivings, a reflexive logic that Together seems determined to test with its every decision.

For as many blunders as Shanks and crew commit during the film’s 102 minute runtime, none are worse than its protagonists’ choice to move out to the country. Leaving behind a big city life filled with friends and frivolity, Tim (Dave Franco) and Millie (Alison Brie), a thirty-something couple whose romantic flame is holding on for dear life, are relocating to the outskirts of Washington, and taking all their baggage with them. A break-up seems imminent until the contemptuous pair stumbles upon a mysterious, shadowy cave that takes a psychic hold on Tim, leaving him in a lust-suffused fugue state for which Millie’s touch is the only balm. Making heads or tails of a partner’s reenergized passion can be tough when familiarity starts to bleed into obliviousness.

Codependency and body horror make for awfully symbiotic bedfellows, and the core idea of Together is so compelling that the movie’s opening passages have the feel of a modern genre classic. Shot in the same stylized, beatific darkness that’s adorned the last decade of high-minded frighteners, the flick’s balance of sinewy thematic cohesion and tried-and-true nightmare imagery is impossibly alluring, and bolstered by its inherent knowability. Even bad relationships don’t take kindly to decomposition, and Shanks cleverly goads his audience into projecting aspects of their worst forays into affairs of the heart right onto the screen. Here’s hoping that those same viewers don’t relate too intimately, because this is one lame duck of a union.

Skewering bad boyfriend behavior is nothing new in the land of ghosts and demons, but Tim is simply too much of a dud to inspire fervor in either direction. A cantankerous hipster chasing indie rocker dreams that are already out of reach, Franco’s character is neither charming enough to be appealing, nor deplorable to the point of delicious villainy. Shanks is clearly offering a mea culpa for all the bratty beta males that straight women are forced to sift through, but the apology comes at the expense of genuine shading, and turns Millie into a reactionary player. Despite being the more capable and charismatic of the two, the movie has little interest in her inner workings, creating the same imbalanced dynamic that it’s supposed to be detonating. There’s no better example of toxic masculinity than being so focused on self-flagellation that you forget anyone else exists.

Perhaps a more enticing headlining duo could have made the same material sing, but Franco and Brie just don’t have the juice. Despite the metatextual allure of having a real-life couple at the center of the frame, the chemistry is all off save a few moments of low stakes comradery, and made worse by dialogue that’s both clunky and heavy-handed. Damon Herriman, the film’s only other character of note, fares far better with decidedly broader tools, but his positioning in the story is too obvious to land what’s meant as a shocking third act revelation. Horror often benefits from the goofy wrong-headedness of hamfisted interactions, but the tightly-wound aesthetic here is the wrong vessel for enveloping tomfoolery. By attempting to have his B-movie cake and eat it with prestige utensils too, Shanks cuts both promising approaches out at the knees.

At least it’s done with a motorized saw, as Together is often at its best when operating in a gruesome space. The flayed skin and cracking bones on display won’t be for everyone, but David Cronenberg fans will be in their happy place when Shanks finally offers his pound of flesh, meted out with proper conviction and a keen eye for upset. The more leering, ornamental torments are nearly as effective, prompting shrieks and seat squirm with equal aplomb. The ratio and cadence here call The Substance to mind, not to mention both films’ interest in buttressing meaty social commentary with corporeal distress, but Coralie Fargeat’s assaultive bombast was overwhelming enough to land her a Best Director nomination. Shanks is more of a working man’s filmmaker, with most of the flick’s optical affronts paying homage rather than charting their own path. There’s nothing wrong with leaning into what’s worked in the past, but it puts a ceiling on a project that had a limited track in the first place.

Not to belabor the comparison, but The Substance had a short-sighted roadmap as well, with both features laser-focused on high concepts that bend toward predictable outcomes. Last year’s gory pop cultural sensation just muscled its way through the finish line, and there’s a chance that the conceit alone here has enough gas to do the same. Together-ing has a nice ring to it, and one could easily envision a world where it enters the lexicon as shorthand for many a noxious, unkillable tryst. Whether a movie with a genius-level launch point even needs proper legs to stand on will be in the eye of the beholder, but accepting the late-breaking pivot to sweeping, disgusting romance is a taller task. Together ultimately asks us to believe in the power of companionship and indefatigable devotion, which is a hard pill to swallow when the cons so greatly outweigh the pros. There’s excitement and illumination in even the most ill-conceived engagements, as long as you know that it’s not really going anywhere.