The Survivalist begins seven years on from this disaster, with one man (Martin McCann) in a wooden hut in the middle of a forest: lush, green, dripping in rain, and his life as he now lives it, in survival mode. His hand is never far away from a shotgun – for which he has a only few shells left – or his hunting knife, which has multiple uses like all his scavenged tools. He surveys his territory relentlessly for intruders, setting animal traps, collecting edible fungi, washing in a lively river, both eyes and ears wide open for unusual sounds.

So when one morning two women, a mother (Olwen Fouéré) and daughter (Mia Goth) appear outside his hut asking for food and shelter, it is not surprising that he goes into instant alert and special forces mode, scanning the landscape, taking elaborate precautions to make sure they are alone before he places bowls of gruel on the table.

Recent life has taught him man eats man; attacks first and tramples later. Strangers are threats, speech is superfluous and even actions cannot be taken at face value.

Trust grows slowly between the three of them, lust becomes tentative love as the daughter is traded for food, and dependence fights with practicalities. There is little dialogue but that does not mean this film is silent. The sound of the trees rustling in the wind, the constant plop of water dropping to the ground, the gurgle and susurration of the river, the crackle of wood on the fire, the creaking footsteps in the hut, all are almost deafening.

As viewers, we find that everyone in this new world is a survivalist, and will do anything to secure a safe place to sleep, access food and seeds to grow, and a chance to live a little longer. They will even poison their own mother, perform dangerous operations on themselves using twisted wire heated in the fire and sanction their own death in order for the others to survive.

Ultimately betrayal shatters human sentimentality, external threats lead to new alliances and loss, with but one character left poised on the verge of the rest of their life. The Survivalist is a grim reminder of how fine the line is between between civilisation and living like a pack animal or lone predator in a wilderness where rape is what happens when a man scents a woman, slaughter when a male meets a rival or when an injured being cannot produce more than they eat. For what matters is the survival of the fittest.

This is not an easy film to watch, and I had to shut my eyes several times when the brutal reality got to be too much, leaving me feeling sickened to my stomach for many hours later. Throughout, you find yourself strung as taut as the tin cans in the bushes and jumping at the slightest noise. But these are the terrible facts of life post-apocalypse.

Think you can handle it? Book now to see The Survivalist at FACT.