During a widespread viral pandemic, a scientist and a park guide head into the forest in a search for a missing colleague. By the time they reach the site of her experiments it becomes clear that they are not alone – and that it is too late to turn back.

After demonstrating a talent for an entire range of genre pictures, English director Ben Wheatley has returned to the folk horror genre that first made his reputation. While In the Earth is a distinctly different film to earlier works like Kill List (2011) and A Field in England (2013), it shares a common dna. It also kickstarts what I suspect will become a trend over the next 12-24 months: films created during, and influenced by, the global COVID-19 pandemic of 2020-21.

The film begins with scientist Martin Lowery (Joel Fry) arriving at what was once the visitor’s centre for a woodland park, now a locked-down base camp near an unusually fertile patch of forest. Martin ventures into the forest with park guide Alma (Ellora Torchia) to find his co-worker and former lover Olivia Wendle (Hayley Squires). Instead they are both attacked in the night, before encountering a strange bearded man (Reece Shearsmith) who isn’t supposed to be there.

It is mightily crowded in the forest: it must surely be the primal site for horror cinema, filled to the brim with witches, cabins, monsters, and various murderous psychopaths. It is clearly tapping into something much older, potently embedded in most cultures around the world. It all makes for an effective backdrop for horror filmmakers, but it also makes it difficult to stand out from the crowd. A lengthy series of city-wide lockdowns have made seeing new features in 2021 something of a challenge for me, and yet I have managed to see the forest act as a site for horror and high-tension thrills in Wrong Turn, A Quiet Place Part II, Come True, and The Empty Man – and my viewing year still has several weeks to go. In the Earth steps into enormously busy territory, and it is testament to Ben Wheatley’s skills as a writer that he still manages to find his own distinctive niche.

That niche is carved out with a combination of three disparate angles, each drawing on their own genre conventions. It is where they interact that makes In the Earth a film worth watching. The folk horror angle is impossible to miss. Before leaving the visitor’s centre Martin is introduced to the local folklore, including drawings of some demonic spirit named Parnag Fegg that supposedly haunts the area. Early scenes in the forest immediately bring to mind Myrick and Sanchez’s 1999 hit The Blair Witch Project. As the film progresses, it starts to shift into multiple directions. There is the sort of ‘untrustworthy stranger’ thriller, that begins with unexpected strangers offering help and usually ends being chased around the house by a maniac with a chainsaw, but there is also a huge apparent influence on the third act by British writer Nigel Kneale.

Kneale remains one of the greatest writers that British television ever had, with an enormous gift for forethought (his The Year of the Sex Olympics play effectively predicted reality TV in 1968) and a tremendous gift for mixing folk horror with science fiction. He is most famous for his four Quatermass science fiction serials, the first three of which were some of the earliest appointment television the BBC ever had. The third serial, Quatermass and the Pit (1958)  based itself around a scientific investigation into a long-buried alien spacecraft that seemed to have inspired centuries’ worth of superstition, supernatural encounters, and religious mania. The very best of Kneale’s TV plays, The Stone Tape (1972) saw a similar investigation attempt to use technological means to understand a supposed haunting. It is this combination of supernatural themes and technological methods that Ben Wheatley has co-opted for In the Earth, and he exploits the tradition wonderfully.

Good horror films rely so much on their cast to sell their premise, and in that regard In the Earth is gifted with an excellent central quartet. Interestingly, both Fry and Shearsmith come primarily from the comedy world (Fry in Plebs and Shearsmith in The League of Gentlemen) yet both deliver strong, emotional performances. Shearsmith in particular is barely recognisable, thanks in part to a thick grey beard and unruly hair as well as to an unsettling matter-of-fact approach to his seemingly deranged behaviour. It is refreshing to see Fry essentially play the film’s increasingly distressed sidekick, relying constantly on Torchia’s steely and resolved park guide to keep him safe. Squires is wonderfully ambiguous in her key third-act role: by this point Wheatley has upped the paranoia enough that her character is immediately suspect, and Squires’ acting does not resolve any questions easily.

While the setting is self-similar – there are only so many ways to shoot a forest – Wheatley keeps the tone varied and effective. The horror elements range from jump scares to rising dread to relatively graphic violence, but there is also a somewhat mean streak of comedy laced throughout. One scene of squeamish violence is deliberately stretched out to extremes, purely to mess with anyone looking away or glancing through their fingers. Clint Mansell’s score is both subtle and effective throughout.

The film’s climax will likely be divisive. I enjoyed it as a psychedelic and emotional journey for the characters, however viewers expecting easy and frank answers will easily become frustrated. One of the remarkable aspects of Wheatley’s film is just how spontaneously came together: written and produced during the first year of the global pandemic, shot entirely on location with a minimal cast and crew, yet still exceptionally staged, wonderfully acted, and deeply unsettling to watch.