Crafting a movie around a real-life tragedy is an understandably tricky endeavour. While James Cameron’s Titanic doomed hundreds to their deaths, pretty much everybody alive at the time of that travesty had long since passed on. Not so with the Snowtown murders, which were committed in an isolated, downtrodden region of Australia not 12 years ago, and are still a justifiably touchy issue for those who live there – not least the families of serial killer John Bunting’s 11 victims.

It’s to first-time director Justin Kurzel’s credit, then, that he approaches the subject with both compassion and sensitivity. That’s not to say that he balks at Bunting’s horrific deeds – though Snowtown is essentially a hard-bitten character study, it’s also easily one of the year’s most disturbing films. Undulating with an unhurried, creeping menace, it positions horror in everyday situations and stealthily cranks up the tension until it becomes almost unbearable.

At the centre of this dark and absorbing drama we find 16-year-old Jamie (Lucas Pittaway). Living with his mother and brothers, he finds a new father figure in Bunting (Daniel Henshall), his mum’s latest, quietly charismatic squeeze. Except John’s idea of educating Jamie in the ways of world involves acts of ever-increasing violence, as first the pair vandalise the house of the paedophile living across the street, and then take part in a little casual murder.

Providing Snowtown with its murky heart, Henshall is fantastic – at once relatable, likeable even, and then suddenly, out of nowhere, a figure of pure terror. Instead of focussing entirely on him, though, Kurzel is more interested in Jamie. Skirting away from vivid depictions of brutality (though when those killer moments come, they freeze the blood), the director wrestles with that most fascinating, perhaps unanswerable of questions: what turns a timid teenager into a ruthless killer? 4/5