The Fly (1986) explained: the killing kind

A retro-style PC with a huge white monitor fills the screen

A scientist turns into a murderous insect in Cronenberg’s classic The Fly – but that’s just one of the film’s many transformations.

When journalist Ronnie Quaife (Geena Davis) meets a socially awkward scientist at a party, she can’t wait to ditch him. Then she learns Seth Brundle (Jeff Goldblum) is working on a teleportation device.

Sensing an incredible scoop, Ronnie agrees to document Seth’s work up-close and (very) personally. Then, one night, the inevitable happens: Seth teleports himself.

After the experiment, Seth grows stronger, fitter and faster than he’s ever been. But what looks like a miraculous transformation comes with terrifying side-effects. You see, when Seth went into the teleporter, he didn’t come out alone …

Come fly with me …

Car sickness leaves Seth Brundle queasy, but science is about to fix that – and all the other inconveniences of travel.

His teleportation device will let passengers climb into a pod in one location, and climb out at their destination seconds later. There’s no need for cars at all – or planes, trains, baggage limits, passports and border control.

Seth thinks he’s on the verge of “something that’ll change the world and human life as we know it”. This being a horror film, his words are about to come true in ways he can’t possibly predict.

The tragedy of this is that Seth’s teleporter really works. He steps into a pod in his living room one night, and walks out of a pod a few feet away. Swats the problem? A fly gets trapped in the pod with him – and Seth’s computer splices their genes together.

Our guy sets out to make a machine that transports people. What he ends up with is a device that transforms him instead.

Initially a soft-spoken, socially awkward nerd, Seth becomes a kind of superhero with incredible strength, speed and agility. Then the mutation accelerates.

Ultimately, Seth’s metamorphosis sees his insect abilities overwrite his human nature – putting those around him in danger.

There are two flies to this story. There’s the fly who gets into the teleporter, and the fly Seth turns into. Which one the title references is one of the film’s many ambiguities.

The fly in the ointment

“Now you tell me: am I different somehow?”

Seth Brundle

The first time we see the telepods, they almost work. The software can send inanimate objects like a boss, but it fails – and fries – when sending living things.

When Seth teleports a baboon, it’s pulverised out of all recognition. Cruelly, it isn’t killed outright, but is turned into a living horror. This closely foreshadows Seth’s fate.

Seth’s a genius, by the way; he almost won a Nobel Prize in his 20s. Since then, however, he’s made some dicey choices. The first is building a high-tech lab in the living room.

Later he muses: “The teleporter insists on being pure. I was not pure.” He means the fly that got into the pod, but conveniently overlooks his very non-sterile lab.

His second bungle is a two-for-one. When Ronnie races off to see ex-boyfriend editor Stathis (John Getz), Seth makes a critical decision fuelled by jealousy and booze. Having successfully sent a second baboon through the machine, Seth now tests it on himself. Alone.

Unbeknown to him (and yet surely not hard to predict!), the pod is contaminated. But instead of aborting the program, Seth’s semi-thinking computer fuses him with the rogue fly ‘at a molecular level’.

The Seth who climbs into the pod is annihilated. What emerges from the other pod is technically “Brundlefly”, a completely new life form composed of both human and fly DNA.

We already have a few clues that Seth isn’t a consistent genius. Here are a couple more: it’s Ronnie’s comment about flesh that (albeit unwittingly) unlocks the secret of teleportation. And it’s Ronnie who discovers the truth about Seth’s transformation when she sends his strange hairs for analysis.

Seth Brundle: spider or fly?

In fiction, scientists who subvert the laws of God and Nature pay the price. Dr Jekyll finds a way to indulge in depravity, but unleashes deadly violence. Flatliners sees a medical student cheats death, only to enter living hell.

In the real world, scientists have tested on themselves to amazing ends. In fiction, self-experimentation is another sin. Consider the outcome of stories inspired by HG Wells’ The Invisible Man, including the 2020 reboot of the same name, and The Hollow Man.

Either way, then, Seth Brundle is due a reckoning. But while it’s tempting to see him as a victim of circumstance, that’s not the whole story.

His mannerisms, and the whole ‘mad scientist’ vibe, hint at genius eccentricity … but also arrogance. Seth doesn’t bother with protocol because the rules don’t apply to him. The boho apartment and jazz piano tell us he’s not a scientist. He’s special.

Similarly, much of his work relies on nameless others: the folk who build his pods, for instance. If Seth is part genius, he’s also part capitalist boss (er, and 0.0001% fly).

What’s interesting with hindsight is how much the modern-day cult of tech innovator / influencer resembles this lifestyle.

There’s the hybrid home-office (compare perks once common at Google HQ). Meanwhile, Seth wears the same outfit every day to free his brain from decision fatigue: see also Steve Jobs and Mark Zuckerberg.

As his insect genes dominate, Seth manipulates and maims others to get his way. But does the transformation merely amplify attributes he already has?

Consider that he lures a journalist to the greatest invention in human history … then begs her not to write about it. In the end, the set-up, and where it takes Ronnie, is another Bluebeard fairytale of bait, curiosity and horror.

Cultural resonance in The Fly

So we know what happens, and we know why it goes wrong (a rogue insect, but also because social and narrative precedents dictate it). But what does it mean?

Some critics have read The Fly as a metaphor for AIDS and, as a product of its era, that resonance makes sense. The first AIDS cases were recorded in 1981. By the late 80s it was an epidemic – not only of illness, but of panic and prejudice (TV drama It’s a Sin charts the effects of both).

Similarly, The Fly is a tragic romance in which one lover contracts a terminal illness. The rest of the world recoils in horror, making monsters of those who get sick.

To be fair, this extends director David Cronenberg’s intended commentary on cancer, ageing, dying and euthanasia.

There’s no end of cultural overlap in The Fly, though. It’s about sickness, but there are parallels with addiction when Seth becomes hooked on teleportation (and sugar), and grooms others to join him.

Interestingly, his sales pitch to Ronnie is that they become a ‘dynamic duo’, i.e., superheroes. Yet it’s likely he also senses looming isolation, whether because of his abilities, illness, or as a monster in the making. Compare Elijah Price in Unbreakable.

Seth also likens himself to filtered coffee, because teleportation makes him pure (no end of irony here!). He talks of waking up to a vibrant new reality that others are too ignorant to grasp – so they hold him back. It’s all rather like prototype red pill thinking (see Taxi Driver).

We can see the shape of earlier narratives in The Fly too. In Franz Kafka’s nightmarish, 1915 story, Metamorphosis, Gregor Samsa wakes after uneasy dreams to find he’s turned into an insect.

The killing kind

“He’ll hunt you if you stay”

Seth Brundle

The Fly is about a man who turns into an insect. Kinda. We could equally argue he becomes host to a parasite that eats him from the inside out.

Either way, the metamorphosis hints at an inescapable ambiguity. Are we born into immutable boundaries of good and evil, or are they fleeting? Is human skin and sensibility a veneer?

This resonates with Ronnie’s abortion angst, when she dreams she gives birth to a maggot. The overlap of pregnancy with contamination and parasites is common across horror, incidentally. See Rosemary’s Baby, Alien and Dybbuk.

Actually, this scene is a warped version of philosopher Zhuangzi’s butterfly dream, a motif of transformation and ambiguity that repeats throughout the movie. It’s what Seth references when he says:

“I’m an insect who dreamt he was a man and loved it. But now the dream is over… and the insect is awake.”

In The Fly, Seth is a good man undone by DNA. The consequences of his poor choices play out as a moral battle between good and evil – between human nature and insect desire.

The implication is that, without human nature, Seth is unthinking and murderous. Yet being human is inseparable from being beastly, whether we talk of evolution or the depths of our depravity. See in particular Split and The Silence of the Lambs.

The men in Ronnie’s life are similarly ambiguous. Seth manipulates her (both as man and fly). Stathis is Seth’s mirror opposite: a creep on the outside, but a hero when it counts.

The film’s final scene encapsulates this ambiguity. Brundlefly has just enough human reason left to ask Ronnie to shoot him. And she does, killing him out of kindness.

The film’s other transformation

It’s fitting that as Seth becomes ‘the fly’, he loses his voice. It’s one more sign he’s losing his human nature (consider the strategic devocalisation in novel Tender is the Flesh).

In The Fly, it’s also a warning this is a one-way journey, because Seth can no longer vocally control his computer.

Seth’s computer is a fascinating character. It may be super-sized tech, but it mirrors the era’s quantum leap in home computing (again, note it’s kept in the living room). As ever, this is laced with fears that machines will replace us, erase or cause chaos: see also WarGames.

This doesn’t get Seth off the hook for his own downfall, though. He tells Ronnie computers are dumb because they only do what you tell them. Incidentally, this implies the computer is an extension of Seth … which is rather telling.

When he teaches the computer how to handle flesh (replicate, don’t rethink), teleportation becomes a reality.

Unfortunately, he doesn’t tell the computer how to handle other errors and … well, we know how that works out.

The semi-sentient computer resolves the fly problem by reinterpreting the two organisms, rather than replicating them. It finds an effective solution – even if it’s incompatible with Seth (see also I, Robot).

‘Machine think’ is the film’s other trajectory of transformation, of course. It begins with a computer in the living room, and sees Seth pierced with a stray microchip (because contamination, people!). Finally, he becomes fused to his own telepod … and the transformation is complete.

The Fly’s body horror reveals a fascination with what lies beneath the human mask. But its other mutation, from man to machine, is the one that mirrors us most in the digital age.


The Fly (1986), directed by David Cronenberg

What to read or watch next
  • eXistenZ (Cronenberg, sci-fi, tech)
  • Jurassic Park 2 (scientists, playing God, Jeff Goldblum)
  • Spider-man (superheroes, insects)
  • Jumper (teleportation)
  • Her (our tech romance)
  • An American Werewolf in London (1980s, body horror)
  • Cocoon (1980s, sci-fi, transformation)
  • The Happening (insects)
  • The Nutty Professor (scientists, transformation)
  • Flowers for Algernon (transformation)

Picture credit: Bert b