Busan 2025 Review: THE GREAT FLOOD, Thrilling Disaster Drowns in Confounding Sci-fi

Following Omniscient Reader this summer, Director Kim Byung-woo returns with his second effects-heavy tentpole this year, the Netflix original The Great Flood, an ambitious film that dazzles and confounds in equal measure.

The Witch star Kim Da-mi plays An-na, a young single mother living in an apartment block who is woken up by her son in the middle of an apoplectic storm. Concern soon morphs into panic when she steps into water and casts her eyes to the windows, horrified to see two feet of water lapping up against the glass of their third-floor unit.

An-na grabs her son, his meds and her phone and tries to make her way up to drier floors. She gets a call from Hee-joo (Park Hae-soo, Squid Game), a security agent who has been tasked with retrieving her. An-na, an AI researcher, is informed that the world as they know it is coming to an end and that she will play a crucial role in the preservation of humanity -- but first, Hee-joo needs to get her and her son safely up to the roof.

Diving almost straight into the action, The Great Flood kicks off as an engrossing and nerve-jangling disaster film, with flood waters rising up the levels of the building, pandemonium ensuing as panic-stricken residents scramble to safety.

Clever and claustrophobic, the film's opening salvo is mightily effective, even if the melodrama is laid on a little thick. It's a shame, then, that it soon stops being a disaster film, and veers off into madly ambitious yet maddeningly asinine speculative sci-fi.

However, the one thing The Great Flood could never be accused of is being boring: there isn't a dull moment throughout. The action on screen provokes many a physical reaction, whether it's your hands gripping the armrests as An-na swims through the rising water and dodges gas explosions or your fingers massaging your temples during most of the exasperating second half.

Kim's work is sadly the latest in a string of exasperating Korean sci-fi stories -- such as previous Netflix offerings Jung_E and The Silent Sea -- which mix and match sci-fi concepts, often borrowed from popular Hollywood tentpoles (the fingerprints of Inception and Interstellar are all over this, to name a few), and repurpose them into cloying family melodrama, with narrative logic largely cast aside.

The melodrama is present right from the start, but it has always gelled better with the disaster genre, which lends itself to families protecting each other or trying to find their way back to one another. Though the subgenre does inevitably churn out a few overly cloying examples, it has also produced compellingly emotional tentpoles like The Tower, Tunnel and Exit, which blended sentiment and sensation, and were each rewarded with box office glory.

Sci-fi has the potential in the world (and out of it) for crafting new visual and narrative experiences and, in theory, it seems like it could be a way to offer novel spins on familiar material. However, as Korean sci-fi has often proved, the ideas and concepts of sci-fi rarely merge comfortably with the emotional registers of melodrama.

Despite the ludicrous scenarios she finds herself in, Kim is a fierce and focused lead, once again proving why she is one of the most compelling young leads on Korean screens today -- she also appeared in this year's strong procedural K-drama Nine Puzzles.

No stranger to action, Park is a nervy and stolid presence as Hee-joo, bolstering many of the set pieces, but, despite its many twists and components, the script never manages to add any layers to the character.

The Great Flood is a spectacle viewers won't soon forget -- but whether its excesses can be forgiven is another matter.