As a child, there’s something peculiarly uncanny and unhomely about your grandparent’s home. On the one hand, it’s familiar to your parents, but, on the other hand, it works to displace your parents as parents at the same time, drawing you into an odd identification with them as you find yourself in their old bedroom and amongst their old objects. In some ways, that sense of the uncanny is the subject of M. Night Shyamalan’s return to classical horror after the fantasy and sci-fi experimentation of The Last Airbender and After Earth. As might be expected, it’s about a pair of children who pay a visit to their grandparents, but the brilliant touch here is that they’ve never actually met their grandparents, who rejected their mother years ago and have invited the children – just the children – to spend a week with them in their rural Pennsylvania home as a first tentative rapprochement. With the film told primarily through a home video that the children make to document their experience, the stage is set for what would already be a fairly uncanny and unnerving experience even if it didn’t gradually devolve into horror, as their grandmother, in particular, starts acting in increasingly erratic, abject and unpredictable ways, especially at night. At first, it’s attributed by their grandfather to sundowning – a kind of temporary dementia that sets in after sunset – and the horror emerges quite naturally from this frequently documented condition, as the children aren’t sure whether what they’re experiencing are genuinely weird grandparents, or just the weirdness of actually having grandparents for the first time. For that reason, the film doesn’t exactly present a lovable old couple who get progressively stranger so much as a couple who already start out as pretty alien, but take a while for their alien qualities to manifest in fully discernible or definitie ways. Somewhat robotic and zombified from the start, they would almost puncture the suspense were this not also Shyamalan’s first fully-fledged horror-comedy as well, a study in agesploitation in which even the most bizarre behaviours are blithely attributed to old age: “Just come to accept that they’re old people, and it won’t be as weird.” For all that that plays as camp, it’s not such an implausible proposition for these children either, with the grandparents more or less relegated to their fringes of their awareness – chopping wood, making dinner, stoking the fire - for the first couple of days at the farm, as Shyamalan perfectly captures the way grandparents can just fill out and texture the backdrop of a young child’s life until something happens to jolt them into sudden visibility. And those jolts are where the film’s horror lies, as the grandmother and grandfather – and their grandfatherly and grandmotherly bodies – are gradually thrust up right against the handicamp, until it feels as if the true horror of the film is in realising that your grandparents are embodied in the same way as you are, and recognising your own reciprocal mortality in the process. For another director, that might make for a somewhat morbid or depressing horror film, but here it veers more towards an otherworldly, alien atmosphere – certainly Shyamalan’s best fusion of sci-fi and American Gothic tropes – in a small-scale film that captures the grandiloquence of being a grandchild in quite a galvanising way.