What’s up with that wild twist in ‘Sorry to Bother You’? Well, it’s part of a long movie tradition.

Boots Riley’s surreal new social satire Sorry to Bother You takes place in a world that’s much like our own — until a twist in the latter part of the film sends it careening into science-fiction. While that reveal may have seemed over-the-top, it’s also part of a long cinematic tradition of using similar devices as allegory. If you haven’t seen it yet and don’t know what twist we’re talking about, look away now, because spoilers abound.

Sorry to Bother You stars Lakeith Stanfield, of Atlanta and Get Out, as the not-so-subtly-named Cassius “Cash” Green. Hard up for money to pay his uncle rent and repair his busted car, Cash takes a job at RegalView, a bleak telemarketing company. The shadow of late capitalism hangs over Cash’s world as it does ours — all around Cash are people struggling to get by, while a dystopian company called WorryFree advertises “free” food and housing in exchange for a lifetime of labor, aka a system that, as characters in the film point out, is essentially slavery.

But Cash begins to excel at work when he discovers that he can sell more by putting on a “white voice,” supplied via voiceover by comedian David Cross. He soon rises in the ranks, and gets promoted so he can sell WorryFree labor over the phone. His newfound success nets him a hefty salary and allows him to afford a beautiful new apartment and flashy car, but puts him at odds with his friends and girlfriend Detroit, an artist and activist working multiple jobs who’s played by Tessa Thompson.

Understandably, Cash is conflicted about his personal gain coming at the expense of other people, but he can’t resist the trappings of wealth, including a special invitation to a party at the home of WorryFree CEO Steve Lift, played by Armie Hammer. There, in Lift’s sprawling mansion, Cash opens the wrong door and stumbles upon a disturbing secret — Lift is engineering horrific human-horse hybrids, called “equisapiens,” who are meant to be stronger and more productive than WorryFree’s human laborers. And Lift has a proposal for Cash: $100,000,000 if Cash will transform into a horse-person for five years and act as a man on the inside for WorryFree.

The flickering-lights, horror-movie reveal of the horse people in Sorry to Bother You might seem out of place even for the film’s exaggerated reality, but it’s straight out of the “mad scientist” trope established by H.G. Wells’ 1896 novel The Island of Doctor Moreau. In the story, a man winds up on a mysterious island where he discovers a scientist who’s been creating human-animal hybrids. The novel was adapted into the 1932 film Island of Lost Souls and two subsequent movies, both titled The Island of Dr. Moreau, one in 1977 and one in 1996. The story also inspired a Simpsons spoof (”The Island of Dr. Hibbert”).

Well’s Moreau creates his human-animal hybrids because he’s, well, a crazed scientist, drunk on his own power — but Riley’s Steve Lift is a Silicon Valley capitalist, not a “mad scientist.” In a satisfying skewering of capitalist ethos, Lift explains to Cash that he, very reasonably, made the horse-people to maximize profits, not for any “weird” reasons, casually telling Cash, “I didn’t want you to think I was crazy.” And, when Cash leaks a video of the tortured horse-people begging for help, the world responds not with horror but with a stock market surge and a celebration of Steve Lift.

In Sorry to Bother You, the “equisapians” serve the story as an allegory with multiple meanings. They are the warped faces of exploited workers, representing literal dehumanization at the hands of a corporate giant like WorryFree and the disturbing evils of unchecked capitalism. The rhetoric about the horse-people also evokes racist stereotypes rooted in slavery; Lift’s focus on their strength and sexuality (the size of the horses’ penises comes up multiple times in the film) sets up the exploitation of the horse people as a metaphor for race, and for subjugation that denies the humanity of the oppressed.

Using animal-human hybrids as allegories for social ills is a cinematic tradition that goes beyond Dr. Moreau. David Cronenberg’s The Fly, which starred Jeff Goldblum as a scientist who accidentally, and painfully, transforms into a half-man, half-fly creature, was released in 1986, during the AIDS epidemic. It was taken by many at the time as a metaphor for the disease — both in the main character’s powerlessness to slow his deterioration and in the social isolation he experiences as everyone he knows turns against him.

In the 2009 sci-fi horror film District 9, aliens arrive in South Africa and are immediately sequestered into a segregated ghetto in an extended metaphor for apartheid with a splash of xenophobia. Wikus, played by Sharlto Copley, is a bureaucrat who find himself mutating into one of the aliens — thus learning a lesson about their mistreatment at the hands of humans like him. (Turning into an animal to learn a lesson is basically a whole other subgenre and shows up frequently in children’s films — think Beauty and the Beast, The Shaggy Dog, and The Emperor’s New Groove.)

But in Sorry to Bother You, the introduction of the horse-people — and the way their existence is essentially accepted by a society trained to celebrate anything that makes a profit — serves as an endpoint for the plot, not a beginning. And Cash’s own eventual transformation into a mutant horse-person isn’t the start of his journey; it’s the natural final step of a system that divides individuals into the exploited and the exploiters. Sorry if that bothers you.