Rarely has a portrait of a sociopath been so enigmatically engaging and mesmerizingly immersive. Affecting neurological proximity, despite a preference for languid master shots and reticent mumbled dialogue, writer-director Antonio Campos, hones and perfects the distancing techniques he implemented in Afterschool, putting the viewer right in the head of the titular killer, even if such adjacency fails to elucidate Simon's motives.

Campos' restless, constantly panning camera gives the impression of surveillance footage, often drifting away from the drama of many sordid bits of business which can still be heard off screen. Turning a blind eye for us, Campos gives only a false sense of security. Cataloguing a room's banal details during heated exchanges, there's an altogether queasier kind of intimacy, reminiscent of childhood fights between parents glimpsed undetected from the top of the stairs. Hyper aware of everything that's occurring precisely because of what we can't see, the room's constrictive dimensions become uncomfortably apparent. What's being said feels closer, more loaded, and impossible to ignore. The hypnotic power of such deliberately stylized camera work, forces the viewer to anxiously wait for the scene to rotate back into view, pulling us in much closer than comfortable to sudden eruptions of violence, which remain psychologically obscured.

The technical sense of manic disorientation is a natural extension of the geographic loneliness felt by Simon, an American abroad who, following a nasty break-up, has fled to Paris in a fit of heedless, bankrupting bonhomie. As Simon navigates the stygian depths of the capital's grubbier districts, the film's sideways equilibrium settles on subconscious self-destruction as he attempts to dispel mounting despair with seedy sex.

At first he is exploited and taken advantage of by a prostitute (35 Shots of Rum's Mati Diop) but he's soon weaseled his way from client to companion and is sharing her bed. Lurking beneath the shy guy next-door naiveté and pervasive Norman Bates awkwardness is a parasitic Tom Ripley-like trickster. Brady Corbet, like Matt Damon, worms his way to sympathy, not soliciting it directly but playing this unlikable devil with an angel's face as so pitifully dependent, you can't help but feel sorry for him, or at the very least, intrigued as to how much further he'll allow himself to fall.

The language barrier may inhibit already limited social skills, but it also allows Simon to act on darker impulses he might otherwise resist and to be someone else entirely. The fox pin given to him by his mother is an indicator of how he's thought of back home (he's certainly sly enough), but out here in a foreign land he gets to roam around like a lion, a diffident twenty-something who doesn't fall to pieces like a lovesick teenager when he's dumped by the only likely girlfriend he's ever had. Between the lack of relationship experience implied in his grovelling, apologetic letters sent home to an ex who wants nothing to do with him and a voracious appetite for fucking the pain away, Simon is disturbingly marooned between sexualized and sexless, implacable resolve filling the gap and perhaps the surest warning sign of his potential for ruthless killing...

If Simon's ill at ease and doesn't understand the city in which he finds himself, this is partly by choice: blocking people and places with electroshock playlists, earphones plugged in like an umbilical cord. The volume of his beats rattle, though he finds himself repeatedly cut off mid-song, the sudden intrusion and intensity of an indifferent city assaultively asserting itself. As much as he tries to ignore it, this Third World quarter of the capital's red light district is – like Simon – blemished by bitter experience, its diffuse dismal aura enveloping him and stirring something dangerous within. In a letter to his ex he bluntly states, "I can't hurt you from here." These scant breadcrumbs of backstory suggest Simon's blossoming urge to kill is an inborn psychotic impulse, though the menace of the vice ridden streets on which he now finds himself should certainly be considered an environmental stressor.

Inescapably, what's churning inside him will soon consume him. Strobe-light scene transitions not only reflect a film cut to a killer soundtrack, but in the way they pulse and shudder, they evoke a visual migraine of the mind. A furious brain scan of chemically imbalanced, sparking synapses, Simon sees a shade of red that casts all women as whores, be they La Pigalle prozzies or not.

Outlining the construct of a killer and his emerging world view, Campos' film haunts us with the knowledge of seeing the kind of casual brutality and profane sexuality that comes so easily to Simon merely in its nascent bloom, the fox well on his way to becoming a lion.

Director Antonio Campos talks to Timothy E. RAW at the 56th London Film Festival about Simon Killer and its predecessor Afterschool. This video has been optimised to be viewed full screen at 720p/1080p, which can be accessed on the tools button when the video is playing. All film clips used by kind permission of Eureka Entertainment.