The first thing you need to know about Primer (2004) is that it's relentlessly difficult to follow. Comprised mainly of high-level physics jargon, interweaving timelines, and very few clear answers, Shane Carruth's inventive debut continues to baffle its audiences a decade later and after many, many repeated viewings. Produced on a shoestring budget, Carruth undertook writing, directing and acting duties, somehow juggling all of this whilst assembling a plot that even its protagonists fail to fully understand.

Primer follows two scientists into uncharted territory as the machine they invent in their garage reveals a hidden function, the ability to travel through time. It's endlessly difficult to explain just how the machine achieves this, and the shortest explanations available online are at least a page and a half of intricate details, but the film's enigma remains possibly its most endearing factor, and the fact that we're still trying to work it all out is a glowing testament to Carruth's vision.

Admittedly the film is initially more frustrating than it is rewarding, and it is a work that requires not just a second viewing, but perhaps a seventh or eighth. The lack of any kind of discernible exposition means that you are essentially left to your own devices in terms of trying to understand what goes on, but for those who do persist there is revealed a surprising amount of depth to this relatively short film.

Fig i: Primer (2004) Dir: Shane Carruth

Though Primer's complexity often takes centre stage, it is, at heart, a film about friendship. If you strip back all the layers of strenuous physics terminology, and forget about the time that coked-up art student tried to explain it all to you at 4am, beneath you will find a startlingly simple tale of two friends falling out.

From my perspective, Primer's script has long been its standout feature, and what it may lack in the visual spectacle often associated with the genre, it makes up for in abundance with tightly wound writing. Delicately balancing unreasonably large ideas such as the consequences of playing god, with relatively simple questions in the vein of "Should we tell anyone?" and "why is it doing that?" the script manages to deal with dense scientific explanation and incredibly concise summation in equal measure.

It is a script that grounds the dimension-bending narrative in undeniable reality by greeting the discovery with the same intense confusion it would be met with if you or I created the box. None of the characters tell you how it works because they don't fully understand it themselves, and they argue and quibble and interrupt each other to no end when trying to.

Fig ii: Abe and Aaron, manipulating stocks with their knowledge of the future.

Combined with Carruth's keen eye for visual detail, the script flawlessly executes a labyrinthine premise without ever straying into excessive imagery, and in this sense it could be considered the realist antidote to the usual grandiosity of the genre. As a result, the writing takes much of the weight of the complexity, rendering it largely invisible and limiting the 'spectacle' to the medium of light-speed conversation. Instead, focus is subconsciously drawn to the film's visual composition, allowing Carruth to tell you about his characters whilst they worry about the concept.

Throughout the film, protagonists Aaron and Abe are shown to be deeply connected and associated through a number of methods. An explicit example would be the costumes they wear - Plain white shirts with different patterned ties. Immediately Carruth tells us multitudes about these two men. That is, they are similar on a surface level, with complementary ambitions, drives and goals, but on a deeper down they have differing ideas regarding more substantial issues, such as what is right and wrong in this situation if no human has ever experienced it.

Fig iii

Fig iv

Fig v

The examples above (Figs iii, iv and v) depict Abe and Aaron in shared, often symmetrical frames, and it is notable that they repeatedly occupy the same side of the screen. This highlights their close relationship and establishes between them a clear sense of trust, routine, and understanding. Carruth shows us in simple terms that there is an undeniable platonic connection between the men and by extension, that the box is a product of their shared efforts. Through this repeated visual motif, the responsibility inherent with the box's use is divided between them, and soon after, when their more intricate ideologies clash, the friends begin to grow apart and the moral debate intensifies.

When they start to deceive each other, creating separate boxes for their own personal use and interacting with their resulting alternate doubles, their onscreen representation suddenly adopts a different guise, and Carruth begins to change the aesthetic dynamic of their relationship in accordance with their changing attitudes towards each other.

Fig vi

Fig vii

Where there was previously a strong visual connection between the friends, we now see the imagery that defined their closeness broken, interrupted or hidden. In Fig vi Abe and Aaron switch from their established sides and Carruth frames them either side of a distinct barrier between them in the form of a petrol station pump. Likewise, In fig vii a similar approach is taken, with another visual separation placed between them and an obstruction of the one element that has bonded them for the entire film - their costumes.

So Primer is a film about the disintegration of a friendship as much as it is about time travel then, and Carruth here deals in the most explicit visuals possible to tell us this. But still, after numerous viewings and attempts to understand the plot, I find myself struggling to understand the event by event chain of development. However, I believe that this complex nature of the film's concept is designed to be so hard to follow for a very specific reason.

Fig viii

If we as an audience are collectively baffled by the script and its massively complex and relentless stream of scientific musings, then perhaps Carruth wishes that we zone out and simply consider the inventors of the device as people in a situation that has driven them apart. The aforementioned visual ideas could be equally applicable if these characters had argued over a love interest, or a money issue, or a religious disagreement, the raw form of the story being a simple exploration of a failing friendship.

If you simply consider the visual representation of these two men as opposed to the brain melting scenario they find themselves in, then theirs becomes a universal idea, suddenly applicable to anyone who has ever argued with a good friend or who has grown distant from a once inseparable partner.

In Fig viii, taken right from the start of the film, before any science jargon or time travelling antics, we see the group all separate in their own distinct spaces, framed through a garage door that looks suspiciously like a roll of film. Right from the outset, Carruth is telling you to watch the film, just the film, and in it you will see the real story. As we zoom (fig ix), Abe and Aaron come to occupy their own frames, and one shot suddenly sums up the entire film whilst we struggle on to understand it.

Fig ix