“The Fin” has mutated mermen, ecological collapse and absolutely no interest in subtle dystopia

South Korean filmmaker Park Syeyoung has taken mermaids somewhere significantly less romantic.

His sci-fi horror film “The Fin” has a new trailer ahead of a limited theatrical run beginning later this month. Instead of beautiful creatures singing from rocks, Park gives us mutated humans called Omegas, pushed to society’s edges after war and ecological collapse reshape a unified Korea.

Clean water is scarce. The Omegas are treated as disposable labor.

One of them, played by Goh-woo, receives a final request from a dying member of his community: find his daughter Mia, who has been hiding among humans, and deliver his fin to her as part of a traditional funeral rite.

His journey crosses with Sujin, played by Kim Pureum, a young civil servant whose loyalty to the system starts breaking apart while she pursues him.

That is already miles away from the usual sea-creature setup.

The mutations in “The Fin” are tied directly to class, xenophobia and environmental destruction. The creatures are visible reminders of what happened to the world, while everyone considered “normal” gets to decide how much humanity the Omegas deserve.

Park previously directed “The Fifth Thoracic Vertebra,” a strange little body-horror film about a mold-covered mattress producing a creature that steals vertebrae from sleeping people. So yes, this filmmaker has form when it comes to human anatomy behaving badly.

“The Fin” premiered at Locarno before traveling through festivals including Sitges and the Taipei Golden Horse Film Festival.

Its U.S. theatrical run begins at Roxy Cinema in New York on November 27 and 29, with Park attending the screenings. Toronto follows on December 1, with additional engagements expected before the film reaches VOD in January 2027.

Fish people inheriting a ruined world may not even be the bleakest part of this one.