Despite the presence of an unusually menacing Benedict Cumberbatch unnerving all on set, it’s this young Australian actor’s otherworldly stillness that lights up Jane Campion’s western psychodrama

Jane Campion’s psycho-sexual western The Power of the Dog is a tremendous film but it is the power of Kodi Smit-McPhee that really adds bite to its bark. The 25-year-old Australian actor has been a fragile, hypnotic presence, with an eerie knack for stillness and intensity, ever since his earliest performances. At the age of 10, he played a boy coping with the desertion of one parent and the breakdown of the other in Romulus, My Father. At 12, he trudged through a post-apocalyptic hell-scape in The Road, then fell in love with a vampire at 13 in Let Me In, the US remake of the Swedish horror hit Let the Right One In. Even his multiplex movies, such as the X-Men outings (Apocalypse and Dark Phoenix) in which he played the blue-skinned Nightcrawler, have felt that bit stranger thanks to his delicate, androgynous features and those pool-sized anime eyes set far apart on his face.

His uncanny quality is crucial to Campion’s movie, which is set in early 2oth-century Montana. Smit-McPhee plays the gangly, effeminate Peter, who spends his days crafting intricate paper flowers and sketching dead animals. His life is destabilised when his mother (Kirsten Dunst), a widowed innkeeper, takes up with a new partner. It is not this stepfather (Jesse Plemons) who poses a threat so much as his sadistic, bullying brother Phil (Benedict Cumberbatch), who taunts Peter and mocks the way he “creeps all over the place, big eyes goggling”.