Chronicling a mother and son survival tale that later reveals itself as a science experiment, The Great Flood is a sci-fi thriller that challenges viewers with its complicated plot. The film demands attention, and at times, a patient viewer will be required to piece together what is really happening. Scenes often carry more than what initially meets the eye, leaving casual viewers struggling to fully grasp the story.
The disaster unfolds in Seoul, where record-breaking rainfall threatens residents. An-na, played by Kim Da-mi, is reluctantly awakened by her 6-year-old son, Ja-in, portrayed by Kwon Eun-seong, who is excited about the “swimming pool outside.” That joke soon turns into a nightmare as water quickly floods their apartment. Evacuations are chaotic, power outages spark panic, and periodic giant waves trap and drown residents. The city streets soon become a mix of rising water and floating corpses.
Amid the chaos, An-na, a leading AI researcher, is assigned a security officer, Son Hee-jo (Park Hae-soo), tasked with protecting her and her son. He informs her about a global flood crisis caused by colliding asteroid debris, threatening human civilization. An-na’s expertise in Emotion Engines for AI becomes vital, and she, Ja-in, and Hee-jo must reach the rooftop of a 30-story building where a helicopter awaits. Things get complicated when Ja-in goes missing, and from that point, the film develops a loop-like narrative as An-na repeatedly attempts to rescue him.
The loop angle is intriguing, but it also makes the plot feel convoluted. It takes a while for viewers to understand that An-na’s experiences are part of a controlled scientific experiment to develop the AI Emotion Engine. The dialogue—“They built human-like bodies with intelligence and the ability to reproduce. The only thing left is the emotion engine”—is central to the film, but it raises questions. Why is this necessary? If humanity is gone, why not start the new civilization? Can AI realistically reproduce?
Visually, the film impresses. The VFX convincingly depict a city under water, and Da-mi anchors the story with urgency and determination. Her performance captures both desperation and determination, and her swimming scenes make her role feel active rather than passive. Park Hae-soo is effective as the security officer, projecting toughness that complements Da-mi. Six-year-old Kwon Eun-seong as Ja-in, however, is tiresome; his performance is uneven, and it’s difficult to tell if the fault lies with the actor or the script.
The film’s emphasis on the mother-son bond sometimes feels repetitive, slightly dulling the tension. While the story’s complexity offers depth, it occasionally drags and confuses. Small details, like the changing numbers on An-na’s T-shirts, are easy to miss but carry plot significance. Viewers unfamiliar with AI concepts may struggle to fully understand the stakes, making some story elements feel inaccessible.
The narrative begins strongly, with a suspenseful and engaging opening. Early sequences grab attention and establish the stakes, but as the story progresses, the focus shifts and pacing slows. Subplots pile up without clear direction, making the film feel cluttered. By the final act, the combination of repeated loops and layered sci-fi concepts leaves viewers more puzzled than satisfied.
Ultimately, The Great Flood is a film that will appeal to audiences willing to engage with complex narratives and layered ideas. Its themes of survival, the limits of human instinct, and the role of AI in a new world are compelling, even if the film struggles with pacing and clarity. While it begins with promise, the execution sometimes undercuts the intensity and coherence of the story.
Release Date: December 19, 2025
Runtime: 1 hour plus
Streaming Platform: Netflix
Director(s): Kim Byung-woo
Cast: Kim Da-mi, Park Hae-soo, Kang Bin, Kwon Eun-seong, Jeon Yu-na and Eun Su.