The Great Flood is a film that, after the initial watch, leaves you a little hollowed out… but in a good way? I loved it, but it wasn’t a comfortable sort of love. It was more like being pulled through something raw and unrelenting and real. The film doesn’t go for easy thrills or disaster‑movie spectacle. Instead, it builds a slow, suffocating tension that sits heavy on your chest. And then, scene by scene, it unravels, and that unravelling is where its power lives. It’s heartbreaking in places, but it’s also gripping in a way that makes you lean in even when it hurts.
I think it’s pretty telling that I started this review six months ago and walked away:
I just needed some distance, I guess.
The story begins at the beginning of the end. An AI researcher, An‑na, wakes up to find floodwater rising through her thirty‑floor building. Her only goal is simple and desperate: get her six‑year‑old son Ja‑in to the roof before the next wave hits. Being a recent widow, it’s just her and the boy. What starts as a straightforward escape quickly becomes something stranger and more disorienting. The building turns into a vertical gauntlet of collapsing hallways, trapped neighbours, and split‑second choices, all while the outside world reveals itself to be far more catastrophic than anyone admitted.
As An‑na climbs, the film peels back layers of truth about the global flood triggered by an asteroid impact, about the governments that hid it, and about Ja‑in’s real origins. Then the story fractures. Events repeat. Timelines echo. An‑na begins to sense she’s reliving variations of the same nightmare, each one ending in separation, loss, or death. The unravelling becomes the point: the more she fights to reach her son, the more the film reveals how tightly controlled her reality actually is.
By the time the final reveal lands (following some heavy foreshadowing that’s obvious in hindsight but which I completely overlooked during my first watching), the emotional weight has already done its work. You’ve lived through hell with her. You’ve felt the heartbreak accumulate over and over and over and over. The premise is about surviving a flood; the heart is about watching a mother’s world collapse again and again until the truth finally surfaces.
And I don’t have a whole lot more to say. It’s so hard to talk about this film without spoilers. The cast is excellent. Kim Da-mi is excellent as Gu An-na. Park Hae-soo is compelling as Son Hee-jo, even if we’re never entirely sure how much to trust him. And little Kwon Eun-seong performs admirably as Shin Ja-in, the young child and object of An-na’s protective instincts.
It’s well-shot. The camera work does a great job of emphasising the horror of the situation, managing to produce claustrophobic shots in stairwells, sweeping outdoor shots that show the scale of the unfolding disaster, and some truly beautiful shots during some important set pieces. These are often underwater shots; those are very well done in this film.
The film isn’t perfect. It could be a little tighter, pacing-wise, but then is that uneven pacing actually quite important? It’s part of what hints at what’s going on, I suppose. It could still be a little tighter in places, especially at the very start, though I understand why the director, Kim Byung-woo, would really want to approach those opening scenes with some deliberation.
I recommend this movie. I recommend it unreservedly and enthusiastically, even if it’s taken me 6 months to come back and finish this review. You can find it on Netflix.