The Great Flood Recap & Full Movie Summary | Netflix

I caught The Great Flood on Netflix last night—the new Korean sci-fi disaster flick that came out of nowhere on December 19, 2025—and it really stuck with me. On the surface, it’s about a massive, sudden flood swallowing Seoul, but it quickly becomes this intimate, heartbreaking story about a mom named Anna (played brilliantly by Kim Da-mi) fighting to save her young son Ja-in amid total chaos. What starts as edge-of-your-seat survival turns into a mind-bending look at loss, guilt, and what makes us human. If you’re planning to watch, stop here—this is a full recap with all the twists.

The movie opens on an ordinary morning. Anna wakes to relentless rain, decides to skip work, and starts making breakfast for six-year-old Ja-in. Then water starts seeping under the door. She looks out the window—entire lower floors of their apartment building are submerged. No warnings, no time to think. She grabs Ja-in and runs, joining panicked neighbors scrambling for higher ground.

They bump into Hee-jo, a stoic security officer from Anna’s job at a secretive UN research lab called the Darwin Center. He’s been looking for her specifically, saying she’s key to “humanity’s future.” As they navigate flooded streets, dodging looters and helping strangers where they can, we learn Anna’s been working on something called an “Emotion Engine”—tech to give artificial humans real feelings.

The big reveal hits hard: Ja-in isn’t her biological child. Five years earlier, Anna and her colleague Hyeon-mo proposed creating prototypes to test emotional development naturally. Ja-in (and Hyeon-mo’s daughter Yu-jin) were grown in the lab for exactly that—gather data on how kids form attachments, fears, joys. The plan was always to take them back after five years for full extraction.

When the flood (triggered by meteor impacts melting polar ice) wipes out civilization, the center prioritizes saving Anna for her expertise. Hee-jo’s real mission? Retrieve Ja-in too—his developed emotions are the blueprint for new humans. Anna’s known this day might come but convinced herself they’d protect him. Reality crashes in on a rooftop helipad: they sedate Ja-in, shave his head, extract everything. Anna whispers something crucial in his ear before they separate her.

From there, the story shifts to a space station—the last survivors orbiting a drowned Earth. The lab director explains: most life is gone, but they’ve perfected synthetic bodies. Emotions? Only Anna cracked that code. Dying from injuries, she volunteers as the “mother” prototype subject. They build a simulation of her final day, looping until she finds Ja-in—perfecting maternal instinct through trial and error.

We watch Anna relive the flood over and over. Each failure resets her to breakfast, but faint memories linger for everyone. She learns—helps a trapped girl she ignored before, fights looters, shares warmth with strangers. Hee-jo (who dies in “reality”) becomes a guide in the sim, pushing her to think differently.

The breakthrough: Ja-in isn’t fleeing—he’s hiding where Anna once whispered he’d be safe (a rooftop cupboard). He remembers too, drawing the same picture endlessly (her face with the helicopter). Their reunion is quiet, tear-jerking perfection—she holds him, promises safety, and the loop breaks.

Final scenes confirm success: synthetic Anna and Ja-in replicas, memories intact, launch toward Earth with others. Humanity reboots from a mother’s love—clones, but with real souls.

It’s bleak yet hopeful. Water destroys but also cleanses, making way for rebirth. No post-credits hook, just lingering emotion. Kim Da-mi’s performance carries everything—you feel her regret, desperation, joy. The effects are solid (those flooded apartments look terrifyingly real), pacing keeps you hooked through the loops.

Not flawless—some side characters feel underdeveloped, disaster scale could’ve been bigger—but the emotional core lands. If you like thoughtful sci-fi like Arrival or Korean gems with big feels (Parasite vibes in the class undertones), this one’s worth it. Quietly powerful. Grab tissues and dive in. What got you most—that reunion or the whole simulation twist?