A female sexual predator comes in a horribly respectable guise in this utterly riveting drama, from Danish-Egyptian director May el-Toukhy, which has the courage to both charm and chill us as it depicts a midlife crisis. With a protagonist that's spiralling out of control and in its intimately captured reactions, it recalls recent festival hit and fellow Scandi drama Another Round, but takes us into far murkier territory. Finding itself without fanfare on its UK release, Queen of Hearts is well worth seeking out; it's the winner of numerous international prizes, including the World Cinema Audience Award at Sundance 2019, and was the toast of the Danish Film Awards (known as the Roberts) this year, where it absolutely cleaned up.

The film gets ample mileage out of the fact that someone can be both a protector and an abuser. When we meet Trine Dyrholm's Anne, she's a spectacular success, a glamorous lawyer righteously advocating for young victims, who lives a charmed life in rural Denmark with her doctor husband Peter (Magnus Krepper) and twin daughters. The cat amongst the pigeons comes when Peter's volatile teenage son Gustav (Gustav Lindh) comes to live with them after being expelled from school in Sweden. After applying her considerable professional experience to the situation, Gustav and Anne seem to come to an understanding. We see that Anne can be impulsive and that she lacks the ability to draw boundaries at work, but when she makes a move on her stepson it's shocking.

Co-writing with Maren Louise Käehne, el-Toukhy encourages us to at first like and later at least understand Anne, casually illuminating her unstable childhood, where she too suffered abuse, and the film is shot in a way that's painfully alive to the conflicting emotions at play. If we have a constant visual reminder of the inappropriateness of the liaison with the casting of the slight, boyish Lindh – who, in real-life, is well into his twenties – the director also illustrates how Anne gets swept up in her desire, unafraid to show how a mature woman can still be ruled by her sexuality and need to be seen as attractive.

The film draws deliberate discomfort from aligning us with someone so troubling – a post-coital gesture that's unmistakably maternal is just one unsettling feature in a film that takes us deep into the nightmare Anne has made for herself, and shows what unbelievably complex beasts people can be. Dyrholm is remarkable, beautifully nuanced in her portrayal and compelling, if no longer sympathetic, even as Anne's mask of saintliness lays shattered. It's extremely astute on the lies people tell themselves, and a nerve-shredding account of what it's like to lob a grenade into your life.

Available to watch on MUBI from Sat 7 Nov.