In The Defects Episode 4, it doesn’t hold back. Every scene adds pressure. The lies are getting deeper. And everyone’s chasing something—truth, power, or just survival.
This episode opens with a calm yet disturbing scene. Se-Hui is sipping wine with her husband. He starts choking. She doesn’t panic. She just keeps drinking. That’s the unsettling part. Her smile doesn’t change. She kills him without a blink. Then calls him “useful.” At this point in the story, the older version of Ah-hyeon is still seen as her daughter. But this family’s truth is already cracked.
Meanwhile, Officer Hyung-seok is trying to track down Si-woo. His investigation leads him to an old photo. It’s of Seok-su. The officer brings it to the assemblyman’s office. He wants answers. But the assemblyman brushes it off. Says the man just looks like his son. Still, once Hyung-seok leaves, we see the truth. The assemblyman knows that’s his son. His real name was Sung-woo. Now, he goes by Seok-su.
Hunt for the Perfect Donor
In another corner of the story, Ah-hyeon’s [played by Won Jin-Ah] gang is searching for egg donors. They’re looking through footage from a secret auction. One woman stands out—a top medical student. Smart, stylish, popular. But no one suspects a thing. She’s their new target.
Ah-hyeon follows her. Watches her get into a van using an “S Card.” That card is the key to the dark side of the bio trade. The next night, Ah-hyeon disguises herself and heads to the same place. She needs access. She pretends to be that student. Shows the S Card. It works. She’s in.
The building is huge. Other women are there too. Each is taken to a separate room. They’re being prepped to harvest their eggs. Ah-hyeon is recording everything through her glasses. She also needs to plug a device into the server room. This will expose their operation.
Back on the outside, Se-hui meets with a congressman. She wants the law changed. She speaks boldly. Says she’ll deal with any “defects” that survive the process. Her tone is cold. She sees people as numbers, not lives.
Ah-hyeon blends in as a nurse. Moves toward the server room. But something goes wrong. One of the “donors” is missing. A guard checks and finds the real nurse knocked out. The alert goes off. Chaos starts.
A Trap & A Discovery
Inside the server room, Ah-hyeon finally plugs in the device. Ju-an helps from the outside. He finds the buyer list. It’s massive. Thousands of names. That’s when Jung-hyeon—the man running this operation—realizes they’ve been hacked. He shuts everything down. Orders the building to be locked.
Ah-hyeon runs. But by mistake, she enters a strange room. There’s a girl there. She’s young. She’s also named Ah-hyeon, played by Kim Ji An. They don’t know they’re connected. Not yet. They lock eyes. That moment lingers. But Ah-hyeon escapes before anything more happens.
Now the guards are chasing her. Jung-hyeon is furious. Ah-hyeon ends up in a lab room. It’s cold and full of storage units. She sees files—babies who failed genetic tests. They were discarded. Some didn’t survive. Some were just erased. Then, she sees her new Ah-hyeon file. She was one of the successful ones. New Ah-hyeon passed.
She looks for more. Finds Ju-an’s name too. Her world starts to break. She finds a metal container. Opens it. It’s filled with test tubes. Some even hold small fetuses. The alarm blares. No time left. She takes what she can.
A Name
Elsewhere, Si-woo calls the younger Ah-hyeon. They were classmates once. He asks her to meet him in secret. He doesn’t know what’s coming either.
Back inside, the guards close in. Ah-hyeon hides in the vents. Slips out. She joins a line of staff trying to leave the building. Just as she’s about to be caught, she reacts fast. Punches a guard. Points a gun. Tries to push through.
Jung-hyeon shows up and fires. A fight breaks out. She gets cornered again. Then Ju-an sends her a small bomb. She plants it. Gets her hands on a gun. Fires in the device. The room explodes.
The smoke clears. Se-hui walks in. Calm. Cold. She shines a flashlight on the injured Ah-hyeon. Then asks how she’s been. And why she came back. Only four episodes remain now. The story has already covered half its arc. But it still feels like everything is just beginning.
The Truth Behind the Masks
Episode 4 doesn’t add noise. It adds weight. It shows how far these people will go. Not for love or justice—but control. Se-hui wants legal power. Jung-hyeon runs a system based on numbers. Ah-hyeon wants answers. She’s not trying to be a hero. She just wants the truth. But the truth is ugly.
This isn’t just fiction. The show brings up real questions. Like how easy it is to cross a line when science and greed mix. It makes you wonder—how far would people go if no one was watching?
You can watch new episodes every Monday and Tuesday on ENA in South Korea. For international viewers, The Defects is also available on Kocowa in select regions. Availability might differ, so double-check your local platforms.
Looking for more insights like this? Our site covers the series weekly. From breakdowns to theories, we try to keep things real and useful. Share this with anyone who’s watching the show. Or thinking about starting. Because The Defects isn’t just dark—it’s smart. And for now, all eyes are on what Ah-hyeon will do next.
Which twist in The Defects shocked you the most so far?
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Kavita Mishra is a dynamic writer and passionate Korean entertainment enthusiast, combining her love for K-pop and K-drama with a flair for storytelling. With a keen eye for the latest trends, Kavita crafts articles that capture the pulse of K-pop idols, chart-topping hits, and the most buzz-worthy dramas taking over screens worldwide.
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