The rape-revenge thriller gets a deliberately thorny and unpredictable remix in this exceptional film written and directed by Emerald Fennell. It bursts with originality and dares to present a fierce feminist statement via the blackest of comedy. It marks Fennell’s feature debut – few first-time films are this unashamedly bold and distinctive.

Cassie (Carey Mulligan) is a medical school drop-out: 30 years old, working in a coffee shop and still living at home. At night she goes to bars and night clubs, pretending to be blind drunk right up the point when some opportunistic man is about to take advantage of her. It is a challenging premise, and is executed in a manner that raises almost as many questions are there are moments of satisfaction in seeing predatory men get their comeuppance. Does it count as entrapment? Is it fair? Is it safe, or sensible? Most pressing: why is Cassie doing it at all?

The answers come powered by a tremendous central performance by Carey Mulligan (An Education), through which she freely expresses both the good and the bad of her character. There is a tradition among films of these genres which depicts their wronged protagonist through a process of lost innocence, life-destroying trauma, and then almost inevitably a vengeful, phoenix-like rebirth; Coralie Fargeat’s impactful Revenge (2017) is an excellent example from recent years. We do not get this with Mulligan’s performance: we do not see the key inciting incident, only the wreckage left behind, and whatever violent rebirth she expresses is visibly broken almost beyond repair. Promising Young Woman teases its audience with the classic rape-revenge narrative, and then furiously punctures it at every turn. The bravery of Mulligan’s acting comes in her willingness to look foolish at times, or vulnerable, or even deeply and actively unpleasant.

Just as impressive – and indeed as difficult – is the manner in which Promising Young Woman handles the male characters upon whom Cassie preys. They are, almost to the last man, initially portrayed as sympathetic characters. They are clean-cut, they laugh with friends over light banter, and they have decent, responsible jobs. There are no suspicious strangers lurking in alleyways: they all appear, more or less, like ordinary people. They look like people we know in real life. In some cases, for male viewers of the film, they look like ourselves. They say things we might say. Fennell is not interested in simple explanations and elements. She does not write and direct obvious villains. Instead she dives into deeply masked, prevalent misogynies that are much more difficult to predict, and which hit very close to home for a great many of us. Nobody at fault here thinks they are a bad person. They have an excuse for everything. The casting is as close to perfect as can be, relying on actors with pre-existing popular images to drive home the point. We instinctively want to like actors like Bo Burnham or Adam Brody. There is a particularly queasy feeling in watching an actor like Christopher Mintz-Plasse – so vulnerable as McLovin in Superbad – go from funny to deeply menacing in the space of two lines of dialogue. The casting also allows for a superb shorthand in storytelling: when the film suddenly needs a character to be immediately recognised as an untrustworthy womaniser, in step Max Greenfield from popular sitcom New Girl to play an uncomfortably real variant on his TV character.

So far so miserable, but it is a testament to the talent in assembling this film that it manages to be as entertaining as it is. There is a savage, bleak seam of from-the-gut comedy throughout. It seems guaranteed to offend some and delight others, but it always comes from a painful place. The balance of comedy and drama is often uncomfortable, but it seems deliberately so. There are outstanding levels of schadenfreude to be had seeing bad people get caught being bad, but as a viewer you are never able to ignore the seriousness of what has been done. That balance is most evident in a particularly divisive climax.

Some moments work brilliantly, and some stumble, but if the price of decent provocation is an uneven film then it seems a price worth paying. Some will call it a timely film; it is honestly a tragedy that it would almost certainly be timely in whatever year it was released. This is a superb feature. Indeed, it feels a necessary one.