Shirley comes into this year’s London Film Festival with an awful lot of buzz. Executive produced by Martin Scorsese and starring the likes of Elisabeth Moss (The Invisible Man) and Logan Lerman (Hunters), it’s an intriguing, if somewhat half-baked, look at obsession and patriarchy.

The premise of Shirley is based around the real-life experience of author Shirley Jackson (Moss), as she grows close to the young couple Rose (Odessa Young) and Fred (Lerman), with Shirley moulding Rose to her will, using her as inspiration for a novel she has long been stuck on. It initially takes a Get Out-esque atmosphere – with a young couple visiting an odd, slightly disconcerting older couple – and director Josephine Decker conveys this uncertainty excellently, with unsettling close-ups, skewed camera angles and intense, shrill music. Both Shirley and her husband Stanley (Michael Stuhlbarg) come across as so odd, particularly the patriarch, who is dominating, intimidating and hugely manipulative. It’s in these early moments where Shirley functions really well, as the mystery around the situation builds and the sense that something is very wrong throbs.

Yet the problem is it never quite lives up the lofty expectations set in this first act. It’s hard to pinpoint why this is, because the story does take on a fascinating and pretty dark turn, building hugely on its characters and establishing room for the cast to really act – particularly Moss, who is by far the standout performer here – but it just feels a little melancholy, and loses some momentum. This isn’t to say it’s not a great watch, but perhaps it’s not as expertly paced as it could be, particularly towards the middle as the state of affairs doesn’t advance in the way the first act had promised.

Yet despite this, the characterisation is simply fantastic. Of the four main characters, they’re all brilliantly played and deeply layered, especially Shirley and her husband Stanley, who is so creepy – nuzzling up to Rose and controlling Shirley’s schedule – which feeds into the film’s main thesis about the damaging weight of patriarchy and how poisonously it can affect women. This is terrifically communicated and the progression of some characters, particularly Rose, prove how the desires and aspirations of men, even good-natured men, completely outweigh and nullify the mobility of the women in their lives. Decker communicates this subtly, but it’s a heartbreaking state of affairs that Shirley attempts to navigate throughout the film.

What’s particularly interesting is how Shirley doesn’t really conform to a specific genre. It has elements of horror with some visceral and disturbing delusions and dream sequences, but is equally dramatic, creating an ambiguous tone that purposefully never gives you too much information. This is certainly Decker’s intent throughout: the time period is never quite clarified, some key characters and relationships are glossed over, and it doesn’t spoon-feed audiences at all, meaning it’s an experience unlike anything else – you’re meant to be somewhat disoriented, second-guessing everything.

And while that is sometimes unsatisfying, it’s often a very enjoyable watch. The dialogue from Sarah Gubbins is terrific – so layered and engaging, with plenty of clever lines – and the execution, from soundtrack to cinematography, all contributes to this disorienting atmosphere that never relents and makes for a very unique experience. While it’s potentially a little unsatisfying and never quite reaches the crescendo it promises, it’s a fascinating character study and a brilliant criticism of patriarchy – a message that is sadly just as relevant today.