The good-cop-gone-bad trope is such an overused one by now that it’s rare to see a film in which such a transformation is in any way shocking or emotionally involving. With the new Mad Max: Fury Road hitting cinemas this week, though, it’s a good time to revisit one film in which the portrayal of a man’s descent from well-meaning lawman to vigilante remains genuinely powerful: the original Mad Max.

Given that it’s been 35 years since its release, it’s easy to forget just what a strange and unique piece of work Mad Max is. It’s the franchise’s second film, The Road Warrior, from which the new Mad Max will apparently draw the most inspiration, and fair enough — the world of The Road Warrior has come to define how we think of post-apocalyptic societies, and its aesthetic can be seen in everything from The Road to the Fallout series.

But it’s the first film that sticks in my mind. The cartoonish villains of The Road Warrior (seriously, main villain The Humungus looks like a Masters of the Universe figurine, and his lieutenant Wez inexplicably wears ass-less chaps throughout) and Beyond Thunderdome aren’t nearly as menacing as Max’s original nemesis, the flat-out terrifying Toecutter, who remains one of cinema’s most memorable villains. And while the second and third films have their requisite action scenes, the scenes of violence in the first film are genuinely difficult to watch. (The scene in which Toecutter and his motorcycle gang chase and attack a young couple in a car is particularly harrowing, especially when you see its aftermath — the young man fleeing half-naked through a field, blood on his buttocks suggesting he’s been anally raped, and his girlfriend left for dead in the car, her hands chained together like a slave.)

The iconic post-apocalyptic setting that has become synonymous with the franchise isn’t really fleshed out until the second film; in the first, we certainly get the sense that something has gone wrong with the world, given that gangs of psychotic bikers are able to rape and murder with apparent impunity, but there’s also television, some semblance of a justice system, and a distinct lack of people eating dog food (which Max famously does a few minutes into The Road Warrior). This makes sense, given the film’s relatively small budget — it cost less than half a million Australian dollars, and one suspects that most of that went to buying cars and then destroying them, with little left over for grand, sweeping shots of a post-apocalyptic landscape. The limitations work in the film’s favor, though — instead of being a portrait of a world gone mad, it is (as the title suggests) the portrait of a man gone mad. The film is unconventional, though, in that the character of Max-as-vigilante doesn’t emerge until very late in proceedings — really, it’s only the last 20 minutes in which Max throws the law out the window.

This leaves plenty of time in which to depict the slow destruction of all that Max holds dear. His best friend on the police force is burned alive in an overturned car, a ghastly fate for the film’s most gregarious and likable character. As a result, Max quits the force, and there’s an extended sequence in the middle of the film where he travels Australia with his girlfriend, infant son, and dog, apparently having left all his troubles behind him. The idyll he and his family enjoy is all the more poignant for the fact that, as a viewer, you know something terrible is going to happen. The fact that it’s a single, chance encounter at a car repairer’s shop that sets events in motion only makes the whole thing more brutal.

The film’s last scene remains genuinely startling, because it’s only in the final minute that we see exactly what has happened to Max. Having exacted his revenge on the gang responsible for killing his wife, child, and best friend, Max discovers Johnny the Kid, the last of Toecutter’s henchmen, lying on the side of the road near a crashed car. It’s here that your average Hollywood film would make a point about the quality of mercy — Max might spit, “You’re not worth killing,” or insist on taking Johnny into custody to face justice. Instead, Max handcuffs his foe’s ankle to the car, connects a lighter and a fuse to its leaking petrol tank, and in a Saw-esque touch, hands Johnny a hacksaw, inviting him to cut off his own foot or perish.

It’s this Max who’s equipped to survive in the wasteland of The Road Warrior and beyond, although it’s notable that in subsequent films he never quite sinks to the depths he does at the end of the first one — Hollywood was already calling. Still, it’s Gibson’s ability to give convincing portrayals of both sides of Max — sympathetic family man and dead-eyed killer — that makes this movie and its successors so effective. It’s a shame that, these days, Gibson is remembered mostly as a crazy person (although, of course, it’s his own fault), because in these films he’s a genuine star, oozing charisma but also — crucially — the sense that there’s something frightening lurking beneath the surface of a man who appears to be a benevolent hero. He’s a good cop gone bad, and for once, that descent is one that sticks with you long after the final credits roll.