S Line- Episodes 3-4

Lies, Lines, and the Fall That Started It All

Episode 3 of S Line picks up exactly where the last left off, with Seon-A’s devastating fall from the school rooftop. The moment hits hard. Hyun Heup watches in horror as the girl crashes to the ground. At the hospital, Seon-A is hooked to a respirator. Barely hanging on.

Detective Han rushes in to find Hyun Heup waiting quietly outside. She claims to know nothing, but it’s clear she doesn’t believe this was a suicide. And she’s not wrong to be suspicious.

Back at school, one of the teachers is missing. Whispers fill the air. Tension thickens. Teacher Jung-woo, asked to lighten the mood, casually drops that he’s called off his wedding. Ouch. He later shows up at his sister’s place, ready to crash for a week before leaving for Canada.

As Seon-A lies unconscious, Han stays close. Meanwhile, Hyun Heup returns to school in her usual silent, watchful mode. Another student points out that Hye-yeong, Seon-A’s relentless bully, is also missing. Hyun Heup starts eyeing anyone wearing round, gold-rimmed glasses.

Then it happens again.

Teacher Jung-woo finds a pair of glasses at his desk. The moment he puts them on, he sees it: red lines above everyone’s heads. And just like Seon-A before him, he’s freaked, especially when he sees the jungle of lines trailing from Detective Han.

Han, still hunting for the truth, speaks with Teacher Kyu Jin and then Seon-A’s sketchy date, Ji-won. The kid offers little help but mentions Seon-A freaked out over something missing. Han checks CCTV... bingo. He catches footage of Hye-yeong stealing Seon-A’s bag.

While having dinner with his sister, Jung-woo opens up about his breakup. His fiancée cheated on him with his best friend. Just when things couldn't feel messier, he realizes his brother-in-law might be sneaking around with another woman in their building.

At the station, Han clashes with his boss, refusing to label Seon-A’s fall a suicide just to appease the school board. He wants the truth, even if no one else does.

Jung-woo starts noticing S Line connections between the teachers. When he asks Kyu Jin what she’d do if she found out someone close was being lied to, she gives the most K-drama answer ever: “I’d want to know, but I’d also watch the drama unfold.” Savage.

A misdelivered package gives Jung-woo an excuse to snoop and avoid a real conversation. Instead, he and his sister reflect on their father’s infidelity. History, it seems, repeats.

At school, a photo of Hye-yeong and the missing teacher surfaces. Meanwhile, Han arrives at the scene of another apparent suicide, this time with a Will left behind. Something’s off. The body doesn’t look like it died there.

Later, Hyun Heup shocks everyone by hanging out with classmates. She’s not exactly blending in, but she’s trying. Han pulls up to talk. When he mentions the glasses, she tells him to find them, then she’ll explain everything.

Meanwhile, Jung-woo catches his brother-in-law (who’s supposed to be out of town) wining and dining another woman. He tails him and spots a hotel key card. Classic. Jung-woo confronts him at the hotel. The guy promises to “fix things” and return to his wife. Spoiler: he doesn't.

The next day, Jung-woo still hasn’t seen his brother-in-law make good on that promise. Instead, he stalks the other woman’s Instagram and discovers she’s pregnant.

When Jung-woo finally gets to his sister’s apartment, he finds her mid-car crash… with that woman. Brother-in-law arrives and runs to the pregnant woman’s side. That’s the final straw. Jung-woo punches him, furious. But then comes the twist of all twists:

Jung-woo’s sister isn’t the wife... she’s the other woman.

The woman in the crash? She’s the actual wife. Neither woman knew about the other. Cue the fallout.

Back at the station, Han revisits the new victim’s Will. Something in it sends him running home. He tears through Seon-A’s room, finds her notebook, and spots a familiar drawing: glasses and red lines.

He checks with Hyun Heup, who confirms it, those glasses reveal S Lines. And with that, Han finally understands the dark web his niece stumbled into.

Obsession, Illusion, and the Cost of Seeing Too Much

Episode 4 of S Line plunges deeper into the unsettling world of red connections and the people desperate to see them. We open right where we left off, on the street, with Hyun Heup finally explaining to Detective Han how the S Lines work. However bizarre it sounds, he listens, skeptical but clearly shaken. He starts wondering: are there more of these glasses out there?

At school, we’re introduced to a meek assistant wearing those now-iconic gold-rimmed glasses. After being scolded, she confides in coworkers over lunch: her real dream is to become an actor. That night, she throws on a wig and checks into a hotel, the same one where Hyun Heup just happens to be working a weekend shift. When Hyun Heup’s friends stop by for a surprise hangout, they spot the mysterious wigged guest and recognize her… as school staff.

Detective Han keeps digging. The further he looks into Seon-A’s behavior shift, the more convinced he becomes that the glasses changed everything. He even dusts off the old case files on Hyun Heup’s father's death, searching for connections. Hyun Heup later confirms his suspicions: Seon-A wasn’t linked to anyone in class. No S Line. Nothing.

Then, another shocker. Hyun Heup spots a new murder case on the news and once again, the suspect is wearing gold-rimmed glasses. It’s no longer a question. There’s more than one pair out there.

Meanwhile, Hyun Heup goes out with Jun Seon. After randomly jumping into a pool fully clothed (why not?), they warm up with ramyeon. She tells him about the S Lines and he believes her. Not because it makes sense, but because she’s got no reason to lie.

Back at the hotel, the school assistant returns, fully in character. She starts reciting monologues about having slept with many men, about watching people from that room, always with her glasses. Through the peephole, she spots her handsome colleague hooking up with an actress in the next room.

The next day, things take a turn for the sinister. The assistant ambushes the actress, knocks her out, and ties her up. Wearing the actress’s dress, she takes her place in the next room for the planned rendezvous. She meets her colleague, repeating her rehearsed lines, stapler in hand. When he tries to leave, he collapses. She’s drugged him.

As he lies unconscious on the bed, she sees blood creeping from his head across the sheets. But instead of panic, she leans into delusion, pretending to have sex with him while watching herself in the ceiling mirror. The performance she always dreamed of, now a twisted reality.

Then comes the self-destruction. In the bath, she pushes staples into her arms, her legs, and her face.

Eventually, the actress escapes and stumbles into the hallway. Hyun Heup finds her and rushes to the room next door, discovering a nightmare: the man is dead, the assistant is bleeding out in the tub. Detective Han arrives soon after. There’s no sign of the glasses.

But Hyun Heup knows how this works. The glasses give people the illusion of importance. They make you feel special. That’s always the hook.

Later, Han returns to the hotel room. He drains the blood from the tub and there they are, the glasses. Sitting at the bottom like bait. He picks them up.

Of course, he puts them on.

And that’s when he sees it: his own web of red lines.

DramaZen's Opinion

Twisted, Tragic, and Totally Addictive

Episodes 3 and 4 of S Line are pure chaos in the best way. Just when you think you understand the rules, the show yanks the rug out from under you... again.

Episode 3 hit hard with Seon-A’s aftermath, messy relationship drama, and the reveal that multiple people might be seeing S Lines. Jung-woo’s story? Unexpectedly emotional. That family twist? Brutal.

But Episode 4 is where things explode. The assistant teacher's descent into madness was disturbing and mesmerizing. Her monologues, the hotel scene, the final reveal, chilling. And now Detective Han has the glasses too?! This just went from weird to what the hell is happening in the best way possible.

I don’t know where this is headed, but I’m completely hooked. These episodes prove that S Line isn’t just about who’s connected, it's about what seeing those connections does to people. And it’s getting darker by the minute.