Sometimes when watching a movie, one can't help but speculate that there were some disagreements behind the scenes, as if the filmmakers weren't quite on the same page about what kind of film they were making.

That's the case with Dave Franco's directorial debut, The Rental, which Franco also co-wrote. It's a decent horror-thriller, but one that's a little undercooked and unfocused. It turns out to be more forgettable than anticipated, leading us to wonder about the truly great, more consistent film that could have been rather than the scatterbrained, less interesting one we actually saw.

In The Rental, two couples — Charlie (Dan Stevens) and Michelle (Alison Brie), as well as Charlie's work partner, Mina (Sheila Vand), and her boyfriend and Charlie's brother, Josh (Jeremy Allen White) — take a weekend trip together to a ridiculously gorgeous home they rented on Airbnb. But they soon become suspicious of the owner, leading to a horrifying discovery within the house.

The setup is solid, and equally intriguing is an early wrinkle the film introduces. It's Mina, who has a Middle Eastern-sounding name, who repeatedly raises concerns about the seemingly racist owner after he rejects her attempt to book the home but accepts the booking of Charlie, a white man, immediately afterward. But Charlie brushes this off, and the group is quick to ignore the red flags that she recognizes, even as Mina seems inclined to turn back home immediately. It appears we could be headed toward a nail-biting thriller that defies expectations and actually has something to say, perhaps about the concerns of people of color not being taken seriously.

Before long, though, the film turns into a fairly run-of-the-mill relationship drama centered around questions about who will learn about which romantic secret, as it explores the group's wildly unhealthy dynamic. It occasionally taps into the fear of being watched by way of some ominous point-of-view shots during this time, but not enough to maintain consistent dread. Mostly it feels familiar, and that only becomes much more prevalent as the film shifts into more traditional horror-thriller territory.

Another issue arises in the latter half of The Rental. Aside from the fact that the characters start making some baffling decisions, the final stretch ends up feeling awkwardly tacked on, focusing on a threat that wasn't terribly present in the earlier parts of the film and seems like it's air-dropped in from another story. As a result, those early sections feel in retrospect like they were just treading water. Even as the film starts to embrace the horror-thriller genre, it still doesn't entirely decide what it wants to be right away, mixing multiple different subgenres together. All the turns left and right, both in tone and in plot, create a sensation of whiplash. One particular twist that hastily disregards some of what was built up in favor of a new dynamic adds to the film's lack of focus, and when yet another new dynamic arrives after that, it's just too sudden.

For Franco, The Rental is certainly not the wildly confident directorial debut we just recently saw from Natalie Erika James in Relic, which maintained a consistent tone and in which every scene felt purposeful, serving the same central idea. Or compare The Rental to Karyn Kusama's The Invitation, another horror-thriller set all in one house and in which things quickly escalate near the very end. Kusama's 2015 film sprinkles in tons of moments that are subtly unsettling throughout, hinting at what's to come. When the narrative bomb finally goes off, it's entirely in keeping with what was set up. When The Rental's bomb goes off, however, it's not as satisfying given that what turns out to be the final conflict of the movie is much more abruptly introduced.

The Rental does get in a few solid scares, but by the time it loops back to a more low-key final montage that sheds the fullest amount of light on what was going on the whole time, it's impossible not to think, “where was all of this earlier?” And it's tempting to envision a version of the movie where what's shown to us at the last moment actually feels like an integral part of the whole story. When the creepiest part of a horror-thriller is the closing credits, that isn't a great sign.

The Rental's greatest asset is its cast, especially Alison Brie, who brings a lot to the film with her Annie Edison levels of simmering rage, especially in one particular reveal scene. The movie all in all isn't a total miss, with a handful of standout beats, including one that makes creative use of the sound of a shower. It just doesn't come together into something truly special, and the way it suddenly switches gears on more than one occasion makes it all too messy. Maybe Franco simply wanted to do too much in his first movie, or maybe he and co-writer Joe Swanberg were interested in the material for separate reasons. Either way, the result is a diverting but rocky trip.