After a horror decade that was driven largely by torture and found footage, Indisious marked a return to the classic haunted house, but with a few twists. Written by Leigh Whannell and directed by James Wan, the team behind the Saw franchise, it starts by following some familiar beats. We’re presented with a suburban American family – father Josh Lambert (Patrick Wilson), mother Renai Lambert (Rose Byrne) their children Dalton and Foster (Ty Simpkins and Andrew Astor) and Josh’s mother Lorraine (Barbara Hershey). We’re also presented with a supernatural entity, which occupies Dalton’s body, and sends him into a coma that doctors struggle to explain. Finally, we’re presented with a group of supernatural professionals – a pair of ghost hunters, Specs and Tucker (Leigh Whannell and Andrew Sampson) and Elise Rainier (Lin Shaye), a spiritual medium who is easily the most memorable character in the entire film, and graduates into the protagonist of the franchise in later films.

For all these familiar genre cues, however, Insidious exudes a dread and terror that is completely its own, and specific to this moment when directors were returning to suspense horror after the ocular assaults of torture and found footage horror. Both of these 00s modes of horror were, in a sense, about the complete breakdown of thresholds – between inside and outside, subject and object, viewer and actor – that animate American life. In that sense, they felt like end points, full stops, and conversation closers in the great lineages of American cinematic horror. By the time we return to the suburban home in Insidious, then, it already feels irreducibly violated, tainted and compromised. Watching it, I was reminded of The Strangers, perhaps the foundational film in this wave of late 00s neo-suspense, which revolves around a couple whose home is invaded by a nefarious cult – but only after the man’s marriage proposal has gone awry in the opening scene, meaning that the bourgeois thresholds that the invaders are supposed to violate are not envisaged as intact to begin with.

The Strangers opens, in medias res, in the moments after this failed marriage proposal, as the couple in question sit traumatised at a pair of traffic lights, no other cars around, caught in a sliding transitory space that seems to confound all the thresholds they have used to structure their lives. Likewise, Insidious opens in the midst of the Lamberts’ move into a new house, right at that mercurial moment when the homeliness of their old place has started to wane, but the new place hasn’t become homely yet either. This is a house that hasn’t yet settled into a home, and Wan suffuses every scene with that unhomeliness, making for a grating chaos and cacophony that refuses to stabilise into a traditional mise-en-scene. A hyperactively mobile camera and off-kilter angles makes it impossible for the audience to ever attach to this space, or to feel at home in it themselves. The same goes for Renai, who is tasked with the unpacking, works in real estate, and feels the unhomeliness especially vividly.

The resulting tone is remarkably similar to that of The Strangers – drab, downbeat, depressive and defeated long belong the invasion even occurs. The palette is so bleached, and the light is so cold, that when the action moves to the clinical sterility of the hospital where Dalton is treated, there’s no shift in the address or atmosphere of the film. So desaturated are some of the scenes that they almost seem to be shot in black-and-white, reflecting the twilight state of Dalton’s coma, along with a Hollywood audience that can no longer believe in the lush mise-en-scenes that sustained an older mode of suburban horror. Despair percolates through everything, especially for Renai, who tries to console herself with the twee compositions that she performs on their home piano (“I been looking west, always looking that way”) but soon reflects that she’s “I’m scared that nothing’s going to change” with this move to a new house.

The stage is set, then, for a profoundly unhomely and uncanny vision – so unhomely and uncanny that it exhausts and eviscerates home invasion horror itself in the process. At first, as in so many films of this kind, the threat appears to come from outside, in the form of a looming figure who passes Dalton’s window, and then a similar vision that appears to Renai. Yet this trope of an external invader is half-hearted, and quickly gives way to a threat that comes from both inside and outside – a threat that is insidious. In the first big set piece, Josh hears a knocking on the door in the middle of the night, makes sure the door is secure, races back upstairs when Renai sees an apparition, and then comes down to find the door has been opened from the inside. During this scene, the house alarm, the main regulator of inside and outside space, continually goes off, further defying invasion from without and invasion from within. When the Lamberts move into Lorraine’s house, the supernatural entity invades it too, but Renai only witnesses this invasion through a window, when she herself is outside, begging the question of whether the entity entered from outside, or emanated from the house itself. Finally, medium Elise Rainier explains that: “It’s not the house that’s haunted – it’s your son.”

During these escalating set pieces, Whannell and Wan ensure that the supernatural entity doesn’t inhere in any one monster, or indeed in any one style of monster. Instead, it lies in the continuous convolutions of inside and outside that turn the house into a giant Moebius strip. The supernatural presences that emerge are partly corporeal, and partly ethereal, not fully realised in either medium, much as the Lamberts learn that Dalton’s plight stems from his capacity for astral projection, his ability to leave his body and travel to another dimension. Elise speculates that Dalton has been astrally projecting in his sleep, but has travelled too far, bringing in spirits from the astral plane who are now starting to claim the house as their own.

With no clear inside or outside, this “other” space from which invasion occurs can only be described in relative terms, as the “Further,” a zone that defies any absolute notion of inside or outside, “a world beyond our own and yet all around us.” Dalton exists in the connective tissue between the house and this numinous space that is “further” from the house. He’s strayed too far from the family home but when he was ensconced at the very heart of that home, deep asleep, in the middle of the night, meaning that his parents can only access the Further from the house as well. The third act of Insidious immerses us in this Further, imagined as everything that lies beyond the ideational orbit of suburbia, the point where bourgeois proprioception ends and the larger world begins. It’s the dark doppelganger of the American Dream, and often recalls the doubled spaces in David Lynch’s films – especially the Black Lodge of Twin Peaks – as when we start to encounter awry 1950s archetypes, ghosts of the Einsenhower era that refuse to give up their power even though half a century has passed.

It’s at this point that Insidious moves away from traditional suburban horror, since the Further is strange more than scary – uncanny in the truest sense – leading Josh, who turns out to have visited the Further himself as a child, to reflect that “I know I was asleep in the dream but I could feel that someone was awake in the house.” Lest the Further simply settle into an eerie tone poem, Wan amps up the grating textures of the film in the third act too, moving between different degrees of saturation, different styles of horror and different approaches to filming. Beyond a certain point, the Further is not even a relative space, but a cinematic dissonance that evokes the continuous convolutions of inside-outside through fractures, fissures and jagged edifices in the texture of the film itself. As in The Strangers, these often revolve around tortured analog ambiences, hauntological relics of an older time – a grandfather clocks, a crackling record player, and a needle being placed on a record, like nails on a blackboard here.

Insofar as the Further has a point of continuity it’s in the figure of Josh, the head of the family, the previous explorer of the Further, and the character who ventures into the Further in an effort to save Dalton. While Dalton does survive, the Further is never resolved, partly because Elise, the best character in the franchise, and the most confident expositor on the Further, is abruptly killed, and partly because Josh seems to bring back an evil entity himself, producing  an inchoate “ending” in which Renai turns around to look at him in horror, and Wan cuts to black, with all the abruptness and auteurist assurance of John Carpenter’s great horror endings, before her gaze can resolve. It’s a non-ending, a relative shift in a Further that cannot be mapped, explaining why the sequel was compelled to start again at this exact moment, producing an even drabber, dourer and danker outing than this morbid moody masterpiece.