Filmmakers Justin Benson and Aaron Moorhead are great ideas guys. Their previous indie sci-fi films Resolution (2012), Spring (2014) and The Endless (2017) all started with enticing, mind-bending sci-fi ideas that were never quite fully realized. Synchronic is the pair’s biggest production to date, featuring major Hollywood actors (Anthony Mackie and Jamie Dornan) in the lead roles and a larger budget to pull off their ambitious sci-fi concepts. But it also suffers from many of the same problems as their previous movies, presenting an intriguing set-up and a disappointing follow-through.

The second 2020 movie to feature New Orleans overrun by futuristic drugs after the similarly muddled Project Power, Synchronic opens with a pair of partiers taking the eponymous substance, little S-stamped pills that promise unknown effects. Perhaps expecting mellow trips, the two don’t realize that Synchronic’s effect is to make them unstuck in time, putting them in the path of various unforeseen dangers. Paramedics Steve (Mackie) and Dennis (Dornan) are called to the scene to deal with the aftermath, and it’s just one in a pattern of strange incidents they’ve encountered lately: A man stabbed with an ancient sword, a woman bitten by a snake that hasn’t been seen in the area in decades, someone burned alive in an area untouched by fire.

RELATED: Synchronic Trailer Takes Anthony Mackie on a Mind-Bending, Nolan-Esque Sci-Fi Trip

Benson and Moorhead build the details slowly, spending as much time on the main characters’ messy personal lives as on the mysterious drug. Steve is dealing with a terminal cancer diagnosis that he’s keeping to himself, and Dennis is struggling to connect with his sullen teenage daughter Brianna (Ally Ioannides). But when Brianna goes missing after apparently taking Synchronic, the movie shifts gears from moody and mysterious into an exposition-heavy procedural. Steve tracks down the source of Synchronic and starts experimenting on himself, determining the rules of the drug’s time travel effects.

Jamie Dornan and Anthony Mackie in Synchronic

The more the movie explains the mechanics of Synchronic, though, the less convincing it becomes, and while the swirling, woozy long takes of the first act can get a little tiresome, Benson and Moorhead are better at artsy misdirection than they are at straightforward techno-babble. Steve’s single-minded obsession with figuring out Synchronic’s secrets and finding Brianna also sidelines Dennis for the entire middle portion of the movie, making it tougher to invest in the friendship that motivates Steve to such extreme actions.

RELATED: Anthony Mackie Recounts His First Crash Landing as Marvel's Falcon

Both Resolution and The Endless are built on similar close male bonds, and Benson and Moorhead are good at portraying that dynamic, especially in the face of increasingly inexplicable phenomena. In the movie’s quieter moments, Mackie and Dornan have a chemistry that suggests old friends who know each other well and don’t have patience for anything less than straight talk. That’s why it’s frustrating for the movie to embrace clichéd speeches about appreciating life while you can and not taking things for granted, as Steve eventually behaves like a cheesy Hollywood stereotype of a terminal cancer patient, only with the added sci-fi context.

Anthony Mackie in Synchronic

As they have on their previous films, Benson and Moorhead share directing and editing duties, while Benson writes and Moorhead serves as the cinematographer, giving them far greater control over the final product than most directors. But taking on so many positions in the production may spread them a little thin, and while Moorhead’s cinematography effectively creates a dreamlike mood at times, especially in the sequences featuring characters thrust into previous time periods, the pacing is choppy, and the dialogue too often swings from elliptical to blunt.

When those initial users start to drift into previous time periods, as a hotel room is gradually replaced by a jungle, Synchronic is enticing and evocative, and that feeling continues over the course of Steve’s various journeys. Every time he travels into the past, the movie shows off Benson and Moorhead’s abilities at creating immersive sci-fi worlds. Steve encounters an alligator and a conquistador in a swamp, shares a fire with an early human in what may be the ice age, and has to run from racist townsfolk sometime in the 1940s or ’50s. The idea of the Southern past being a dangerous place for a Black man comes up more than once, but it’s just one more intriguing avenue that Benson and Moorhead fail to explore fully.

Despite all the sci-fi mumbo-jumbo he has to spout and the sometimes treacly emotional speeches, Mackie holds the movie together with his energy and charisma, and Dornan finds some genuine pathos in Dennis’ anguish over his missing daughter. Whether they’re hanging out shooting the breeze together or trying to understand the secrets of the universe, they make for an appealing team. Between the onscreen talent and the resources for those sci-fi explorations, Benson and Moorhead have plenty to work with here, but they still can’t quite satisfactorily bring it all together.

Starring Anthony Mackie, Jamie Dornan, Katie Aselton and Ally Ioannides, Synchronic opens Friday, Oct. 23 in select theaters.

KEEP READING: Netflix's Project Power: Every Ability Seen in Action