The events leading right up to the 1996 Port Arthur massacre, though not the event itself, are depicted in this new drama from Justin Kurzel. Martin Bryant, played by Caleb Landry Jones, lives with his parents in Tasmania. He is clearly mentally challenged and has a history of getting into trouble. Incapable of having a normal relationship or holding down a real job, he makes some money mowing neighbours’ lawns. It is doing that, he meets the wealthy older eccentric Helen (Essie Davis) who lets him move in with her. Helen soon dies in a car crash, which the film suggests is Martin’s fault, and his despondent Dad commits suicide. Martin goes off the rails even more and purchases a cache of weapons.

This is frequently an uncomfortable watch, and I imagine a lot of people will struggle spending time with these characters. I admit, I did have those feelings as Martin clearly became more unstable and Helen indulged him. What it does have though, is an important message about how shockingly easy it is for people to acquire assault weapons in some countries. In this instance the shopkeeper asked him for a gun licence and Martin admitted he did not have one. But he was still able to make his purchases when he agreed not to register the weapons. As stories emerge from the US over the last couple of days about how the latest mass shooter, Robert Crimo, obtained guns despite previous arrests and threats to kill, this film feels very prescient.

It also has excellent performances. I have had issues with Landry Jones in the past but he is frighteningly believable here. Anthony LaPaglia gives a moving performance as he well-meaning but ineffectual father. Best of all, though, is Judy Davis as his Mum. She veers between loving her son and frustration with him, that teeters towards hostility brilliantly well.

So, why am I not giving Nitram a higher rating? For all that it is creditable about it, it does quite often feel like it is treading water up to its inevitable conclusion. We know what is coming and quite early can see how someone like Martin would commit the heinous crime.

Rating: 7.5 out of 10