About the film

Below Bonghwa is a Korean horror trailer made with director Dave Clark. It’s loosely based on a true story: in late 2022, two South Korean miners were trapped for nine days in a collapsed zinc mine in Bonghwa County and survived on instant coffee. The film makes things considerably worse for its miners by putting a bulgasari down there with them — a monster from Korean folklore that eats metal and can’t be killed.

The trailer premiered at the Bucheon International Fantastic Film Festival (BIFAN) in 2024, where Dave was speaking at the festival’s AI conference. Chronologically, it’s the first film in this collection — the one that kicked off everything that followed.

How it was made

The whole thing came together in a couple of days, with roughly nine hours of total production — and about 80% of it coordinated over text message. Stills were generated in Midjourney and upscaled in Magnific, then run image-to-video through Kling and Luma’s Dream Machine, with a few Runway Gen-3 shots added after Gen-3 dropped mid-production.

Kling refused to generate the monster outright (a content warning, every time) but had no problem as long as the creature stayed in shadow. Luma’s then-new keyframes feature pulled off the reveal — the miner turning to see what’s behind him.

Post ran the footage through Topaz for an upscale, then FilmConvert to put the grain and scratches back, plus a layer of VHS distortion for a found-footage look. Voices came from ElevenLabs’ multilingual model, with Dave’s mom checking the Korean translations. ElevenLabs also handled most of the sound effects; the pulsing horror score is Udio.

As Tim put it in the walkthrough: an AI-generated Korean horror film, made by two Americans, using software from China, Poland, the US, and Spain. The video above is the trailer followed by the full breakdown — the tools, the timeline, and how the premiere went.