The filmmaking duo of Aaron Moorhead & Justin Benson has hit upon a very reliable schema - I will not call it a formula, because it's not really the same thing every time. But in every one of their films, we see a quiet story about the relationship between two people filtered through a mash-up of genres, one of which is sci-fi, as well as an ingenious ability to maximise the genre elements through the judicious use of visual effects that, because of how they are worked into the movie, feel a great deal most polished and costly than was the case. None of their features has been an undeniable masterpiece, but they've comfortably established themelves as two of the most reliable creators of indie-scale sci-fi epics: they are thoughtfully and carefully written, and executed with obvious love of the craft.

Their newest feature, Synchronic, makes it four-for-four, following 2012's Resolution, 2014's Spring, and 2017's The Endless. The film is the most straightforward, easy-to-follow in the filmmakers' career, and their first one made with Real Movie Stars, though in neither case does this feel like a compromise, or like they're selling out and going mainstream. And it does mean that this is probably the best place to try jumping into their low-key sci-fi worlds, if you haven't had the pleasure.

The basic thrust of the plot is, at least initially, a combination of detective procedural and surreal horror. As we see in the first scene (one of the few moments in the film to go all-in on visual effects, a simple trick of priming to make us think that there's more visual trickery going on than is actually the case), a new designer drug is going around New Orleans, one that causes some particularly vivid visual hallucinations in the user, such as the growth of a primordial forest in the room where one is sitting, or visions of people moving through material like they're out of phase with reality. They also, though no mechanism that makes any sense, seem to cause a wide array of impossible accidents: one user burns to death, another suffers a bit from a snake that hasn't been found in Louisiana for decades. This is where paramedics Steve (Anthony Mackie) and Dennis (Jamie Dornan) come in,, and where the film starts to share its actual interest, which has nothing to do with the drug, and everything to do with the tensions on a longstanding friendship between two middle-aged adults whose lives have gone in very different directions: Dennis has a wife, Tara (Katie Aselton), and an 18-year-old daughter, Brianna (Ally Ioannides), and he likes to complain about both of them; Steve is hitting the age where you start to suppose that it is officially too late to end up with a long-term partner, and are consumed with regret about that fact; it's not helping matters that he's been given a terminal diagnosis, with one of those really unpredictable cancers where the prognosis is a very helpful "could be six weeks, could be 60 years". This is already doing quite a bit to put a strain on the men's relationship, something Dennis doesn't even seem to realise; things get much worse when Brianna takes the drug, Synchronic, and her side-effect is to just straight-up disappear into thin air. This crisis reveals the depths of Dennis's helplessness, especially once Steve takes it upon himself to to investigate what the hell is going on, and in the process discovers just what the hell Synchronic is.

This brings us around a third of the way through the film, by which point I was pretty sure this was Moorhead & Benson's best film yet. The film balances three very different modes very deftly: first, there's the relaxed paramedic procedural, watching as two professionals navigate a very bizarre mystery in the course of their daily work, both excited by a change in routine and terrified by how inexplicable it seems, all set in a very loving portrait of New Orleans as a city where people live and work rather than a collection of tourist-friendly images. Another is the mood of heavy apocalyptic horror that covers the movie like a hot blanket: Moorhead's cinematography is full of robust color grading that makes the air seemed poisoned and bacterial, while he sets the camera drifting through long, sinewy shots that float around spaces with a dreamy weightlessness that creates a hallucinatory mood to the proceedings. The third is of course the character drama, which finds Mackie and Dornan doing wonderful work balancing each other out and suggesting the comfortable, relaxed cadences of two people who know each other well enough that there's not even really a reason to talk about anything. It's a superb central relationship made up entirely of innuendo and implication; the film never needs to underline, say, the fact that Steve is African-American and Dennis is white to let us see how that plays across their relationship, nor does it actually need to have Steve openly declare how envious he is of the life Dennis is squandering, though this doesn't keep Benson from putting lines that effect in the script.

The remainder of the film shifts pretty strongly twice over, though it happens naturally enough that it doesn't feel noticeable as it happens. First, Dennis is greatly diminished as a character, whichย  probably "needs" to happen, but it noticeably damages the film's emotional impact, and makes it basically just a fun sci-fi adventure lark. And that's the other thing: it stops being a horror-tinged mystery, and becomes a time travel movie, as Steve begins hopping around the centuries. This happens, again, so smoothly that it doesn't even really register as a shift, which I know isn't how it sounds. And the sci-fiย  elements of the film are pretty delightful in their own right: Mackie is great at playing Steve's initial confusion and awe giving way to an indignant rage at how shitty most of history is, and how especially shitty it is for someone of his skin color, and the bluntly unromantic way the film plays with the traditions of time-travel narratives gives the film a nice sarcastic bite.

Somewhat surprisingly, this is all played pretty straight: there are no real mechanical tricks to speak of in the screenplay, which basically just watches Steve figure out the rules by which time travel works in this universe, and then apply what he learned. There's an appeal to this, particularly as it fits in with the movie's emphasis on character; it feels intimate and non-epic in a way that's true to Steve's personality, is maybe the best way to put it. It's a very different film, with different strengths, than the first two-fifths; and they are maybe not such strong strengths. But between the omnipresent atmosphere of the world on the brink, the quiet depth of its character sketch, and how well the film creates an elaborate sci-fi world mostly through simple filmmaking tricks, Synchronic always works on a scene-by-scene basis. I prefer Moorhead and Benson when they're being a little more baroque, I cannot lie, but this is still awfully satisfying stuff, and continues to suggest that these are two of the most interesting people currently working in sci-fi cinema.

For more about the film, check out Rob & Carrie's interview with Justin Benson and Aaron Moorhead!