The Hole in the Ground opens on a sweeping view of an emerald forest, trees marching out into the horizon for as far as the eye can see. It is majestic, and undeniably beautiful. And yet, as Stephen McKeon’s ominous score makes very clear, something terrible lurks beneath that lush green façade. Cue the camera slowly rotating on its axis, flipping us upside down and making it look an awful lot like that tiny Range Rover weaving its way along that woodland road is driving downwards… straight to hell.

Inside that seemingly doomed automobile is Sarah O’Neill (Kerslake) and her young son, Chris (Quinn), who have upped sticks to set up home in this isolated spot. Domestic bliss, however, soon comes to an end when they decide to explore the woods outside their home. Out there in the centre of the forest, where the light struggles to trickle through the dense branches, they stumble across an enormous gaping sinkhole.

A perturbed Sarah reminds Chris that he must never play in the woods alone, lest he… well, lest he fall into a hole and die. But Chris, of course, ignores his mother’s sound advice and disappears from his bed one evening. 

There’s nothing to say that Chris fell or climbed into the sinkhole during his brief absence – he just turns up back in his bedroom, shadily claiming to have never left. However, from that night onwards, something about Chris seems… well, it seems off. His manner is different, his tastes have changed, his appetite is suddenly enormous – and he seems to have forgotten some key details about his and Sarah’s life together. Things are worse whenever Sarah falls asleep: in her dreams, Chris violently attacks her.

Somehow, Sarah is able to push her concerns from her mind. Children change before their parents’ eyes all the time, she reasons with herself. A disturbing encounter with her neighbour (Kati Outinen), though, suggests that there’s more to Chris’ altered personality.

“He’s not your son,” shrieks the elderly woman. And, when Sarah watches Chris track a spider down and gobble it up one evening, she feels somewhat inclined to agree.

Horror fans will already know the broad brush strokes of the ‘possessed child’ storyline, and Cronin’s film doesn’t deviate from this paint-by-numbers formula. However, the director has done his best to add his own stamp to the genre by taking inspiration from the rich tapestry of Irish folklore and legend, and there’s also a nod towards the many kinds of family secrets that some feel the need to bury and keep hidden – with a particular emphasis on domestic violence. It is implied (with almost zero subtlety) that Sarah moved to this hauntingly isolated spot in order to escape an abusive marriage. That the scar on her forehead was the result of a violent run-in with her ex. That she is terrified, however much she may refuse to admit it, that her Chris may take after the vicious man she once loved.

Could it be, then, that her fears of seeing her son grow up to become a monster have addled her judgement? Cronin certainly wants us to think so, using disorientating cuts and colour palette shifts to keep us confused, off-kilter and unbalanced. He zooms in on the pills Sarah is taking to help her sleep, shows us rubbing at her head whenever something strange happens, spends just a little too long on the woodland motif running through the décor of his protagonist’s home, and constantly works to yank the rug out from under our feet. 

Despite its eerie build-up, though, the film loses its way (and all sense of what it’s set out to achieve) in the last 20 minutes as it surges towards its shock ending. And it’s also worth noting that Sarah lacks the nuance and complexity of horror heroines past (Hereditary’s Annie, Halloween’s Laurie, Alien’s Ripley). This is a woman who doesn’t raise her voice at Chris, no matter how badly behaved he’s being. Who doesn’t hurl abuse back at her eldritch harasser. Who doesn’t defend herself when her son brands her a liar. And who, even when she strongly suspects her child is a demon in disguise (we’ve all been there), still kisses him on the forehead and tells him “I love you”.

It is for these reasons that The Hole In The Ground is knocked down to a three-star rating. Because, while Kerslake is brilliant at portraying a woman who is progressively disturbed by the presence of her child, the midway shift in Sarah and Chris’ mother-child relationship doesn’t feel as scary as you’d expect (primarily because they were so abnormally happy to begin with). And, when it comes to horror, scary is key.

Image: Vertigo Releasing