According to producer Timur Bekmambetov and director Aneesh Chaganty, Searching forms a critical release in a series of screen thrillers – thrillers set entirely on laptop and SmartPhone screens – that will be unrolled over the next couple of years. It feels that way too, since, like 2014’s Unfriended, this is a film that seems to envisage a new kind of genre, rather than just a new kind of thriller, even if it goes about that project in quite different ways. At its heart is a missing person narrative, as widow David Kim (John Cho) misses a couple of crucial calls and Facetime requests from his daughter Margot (Michelle La), only to find that she has gone missing the next day. With the help of Detective Rosemary Vick (Debra Messing), David starts to investigating Margot’s social media profile, moving across her Gmail, Facebook, Tumblr and Instagram accounts, while building a web of associations that gradually stretches far beyond their San Jose suburb and immediate family connections. While it might seem as effortless and casual as all social media interactions, the film becomes more tightly plotted with each turn, setting up links, clues and red herrings that only crystallise hours after you’ve watched it, and all demand a repeat viewing.

Obviously, Unfriended is the clearest point of reference here, but unlike Unfriended Chaganty tends to move around the laptop screen, adopting a more classical film syntax in which close-ups, pans and shifts in scale are paired with the actions taking place in digital space. At the same time, Searching is not as directly linked to any one device as Unfriended, instead consisting of footage that could conceivably be watched on a laptop or a SmartPhone, but that isn’t necessarily or consistently tethered to one screen. In doing so, Chaganty beautifully captures a world in which things may still happen away from laptops and SmartPhones, but are ultimately unthinkable without them – a world in which we are always, at some level, thinking about how we can mediate stuff through our screens, even if we don’t actually end up doing so. Actual cinematic experience falls into that category as well, since one of the key alteractions in the movie takes place in a multiplex cinema queue, evoking a media environment in which going to the movies is still a part of everyday life, but in which that space is immediately and pre-emptively contained by digital media as well, much as the screen thriller itself brokers digital screens for the sake of cinematic longevity.

For all those reasons, Searching never feels confined by the laptop and SmartPhone screen in the same way as Unfriended. If anything, this feels more expansive and peripatetic than films that simply unfold in “real” space and time, making you realise the extent to which lived space now only becomes lived space by virtue of being mediated through a computer or a phone. While it may be a thriller, much of Searching captures the lived-in, domestic homeliness of social media, as well as the extent to which social media has broken down all distinction between diegetic and non-diegetic space, between what happens on a screen and what happens around it. In many of the best scenes, David’s laptop creates the atmosphere of his domestic life as much as drawing from or accompanying it, whether in the form of a relaxing classical motif that turns out to be one of his favourite YouTube links, or an eerie expanse of night that turns out to be the backdrop to his all-night screensaver.

Of course, that homeliness of social media also means that the unhomeliness, and uncanniness, of social media is even more pronounced here, at key moments, than in Unfriended. No doubt, as some critics have pointed out, there are some conventional elements to Searching, which might be fairly underwhelming as a thriller if it were filmed away from these screens and interfaces. Yet that just captures the extent to which conventional, run-of-the-mill realism now needs to be mediated in this way to feel “real” in the first place, suffusing the film with an intensified normality that is quite uncanny on its own terms, and produces some remarkably scary and unsettling images. Most of these revolve around stock photography and stock images – intensified normality par excellence – which weave their way into the narrative as David’s quest takes him both further afield and closer to home. As with Unfriended, his estrangement from his own screen is a key part of this process, whether in the hesitation of the cursor and editing of messages, or in his recourse to his deceased wife’s account and email address in order to glean whether she might have left anything behind that can give him an insight into Margot’s current location.

Still, it’s through Margot herself that David finds himself most estranged from his laptop, since as the film proceeds, and he peruses her social media accounts, he discovers a distended adolescent subjectivity beyond anything he could have imagined from their encounters in person. Critically, there’s nothing especially – or immediately – creepy here, beyond the fact that Margot seemed to be a bit of a loner despite having a plethora of Facebook friends and Instagram and Tumblr followers. Instead, it’s the sheer diffusion of her digital life that’s most unsettling, as well as David’s gradual prescience of a dispersed adolescent lifeworld that becomes even eerier and uncannier than the investigation itself. Many of these scenes reminded me of the spooky sequence in Beware the Slenderman in which the filmmakers simply perused the YouTube accounts of the two girls who were charged with trying to murder their friend, documenting a series of videos so random and distended that their cumulative dispersal was eerier than any single piece of content. In Searching, this process doesn’t culminate with YouTube, but with YouCast, a fictional, anonymous, video chat roulette that Margot was apparently using for months. In one of the uncanniest moments in the film, David sees himself comes into the frame in one of the archived YouCast videos he is examining, suddenly realizing the extent to which his own life, and his own relation with this interface, has been globally mediated by Margot’s presence.

In that sense, Margot’s social media presence becomes a spectre haunting David’s house, just as her socially mediated self becomes the really threatening entity in the film, quickly exceeding anything that could have been done to her. As the daughter that David knew fades into one interface after another, she becomes a locus of unbearable mediation, or hypermediation, culminating with the pre-emptive offer that David receives for a live-streaming funeral service. In contemporary digital culture, no genre aims for that level of hypermediation quite like true crime, which might start out in one medium – podcast, documentary, television series – but typically functions as an incitement to discourse, and an injunction to mediation, encouraging users to share the true crime narrative in question over as many media platforms and interfaces as possible in order to arrive at a convergent, shared truth. For that reason, Searching often seems to draw on this true crime corpus as much as upon Unfriended, moving between the piecemeal aesthetic of Mosaic, the vocal style of Serial and the investigative momentum of Making a Murderer, to build a profoundly ludic atmosphere, a sense of infinite digital play, that seeks to evoke all the hypermediated and transmedial possibilities of a true crime text within the original ambit of the text itself.

No surprise, then, that David can only solve the case by deciding to act like a true crime fan himself, researching Twitter theories, and perusing photographs on Reddit for evidence, until he starts to realise that it’s the very people who seemed most exempt from the social media matrix surrounding Margot’s disappearance who have been the most mediated all along. In the process, he also realises that the expanding interface of this hypermediated event is, in some sense, where Margot can be found, at the elusive point where every screen she has used converges upon her presence. Yet if David’s investigation teaches him anything, it’s also that Margot’s social media presence was inherently divergent, disjunctive and distended, with the result that, when he does find her, it still feels as if a part of her is missing, or a part of her is still out there amidst the social media interfaces where she dispersed herself. In other words, the discovery of Margot’s body, and the banality of her disappearance, just makes her digital divergence all the more unsettling, just as the intensified normality of Chaganty’s social media world makes its uncanniness all the more resonant, lingering in your mind long after you’ve seen it, in the eeriest thriller of the year.