Teach You a Lesson Episode 3 Recap

Ga-yun's murder and the bureau's beginning

Two years earlier, Na Hwa-jin, a soldier on a rare day off, walks his fiancée Choi Ga-yun to the school where she teaches. She reminds him that he promised to protect her, and he plays along like a recruit. Ga-yun says the world is finished once adults grow afraid of children. Then she goes straight over to stop a group of students smoking.

In court, Ga-yun is described as a brave teacher who went out of her way for Cho Gyu-cheol, a student who extorted and beat classmates and frightened his teachers, before he committed a heinous crime against her. Gyu-cheol tells the judge he was in love with her. Citing his youth and troubled family, the court gives him a maximum of four years in prison. Afterward, Hwa-jin goes after Gyu-cheol with his car and has to be held back.

Choi Gang-seok, Ga-yun's father, tells the sobbing Hwa-jin that her death was not his fault and that he should look for the right path, not the easy one. Gang-seok says he will soon be Minister of Education and will create the Educational Rights Protection Bureau (ERPB) in his daughter's memory. He tells Hwa-jin to call him if it ever becomes too much.

A viral lie at Soyeon Girls' High School

In the present, Hwa-jin and Deputy Director Bong Geun-dae brief Gang-seok on the bureau's next school. A teacher there was accused of sexually assaulting a student, resigned and took his own life. The case was closed on her word alone after public opinion turned on him. Geun-dae traces the first video to Han Ye-ri, a student with more than 600,000 followers, and explains how tagging spread it across platforms.

Earlier, at Soyeon Girls' High School, math teacher Jung Seon-yeong confiscates Ye-ri's phone while she livestreams in class with her best friend, So-yeong. Soon Ye-ri posts a clip of Seon-yeong cutting gum out of So-yeong's hair at the girl's request, edited to look like abuse. Ye-ri's homeroom teacher, Ko Yeong-su, asks her to repost it with the original sound, since he watched her strip the audio and add sad music. She says she will think about it.

Instead, Ye-ri posts a tearful video accusing her homeroom teacher of sexual assault. Abuse floods the comments, and a stranger corners Mr. Ko at school. His wife calls to say people are gathering outside their house now that the address has leaked. Behind a locked door, staff find that Mr. Ko has taken his own life.

When Seon-yeong demands a correction, Ye-ri, live on camera, turns it into a tearful account of Mr. Ko touching her and ends the stream. The principal asks Ye-ri to make peace with Seon-yeong in exchange for the school's support, and Ye-ri asks for a favor in return. Seon-yeong becomes homeroom teacher of Ye-ri's class, where the girls whisper that she took the job to get at Ye-ri.

Back at the bureau, Geun-dae worries about Ye-ri's fame, but he is told the size of her audience does not matter. Hwa-jin says that this time he has a new recruit in mind.

Im Han-rim takes over the classroom

Seon-yeong introduces Im Han-rim to Ye-ri's class as a trainee math teacher. When So-yeong asks about her plastic surgery, Han-rim says she had a reduction because martial arts needed room to swing. Then she notes that no one in the room has that problem. She orders every phone handed in. Ye-ri, still live, dares her to explain herself to the followers, and what Han-rim does next leaves the class gasping.

Han-rim reveals she works for the bureau and will treat any student who mocks or defies teachers as a lawbreaker. An alarm exposes the girls who held back phones. A broadcast places the school under the bureau's authority, with no limits on its methods. In the teachers' office, Hwa-jin hands out a survey on violations of teachers' rights, but the staff insist there are no problems.

At the snack bar, Han-rim reports to Hwa-jin as a Special Task Force reserve sergeant first class who served in his old unit. She greets Geun-dae, a top KAIST graduate, by leaving him groaning. Hwa-jin says he hired her because she is a lunatic, and she agrees that with today's students, "We fight crazy with crazy." He has one rule: she must never kill anyone. When the urge comes, she should write the character for patience on her palm three times. Then the bell rings, and Geun-dae, who is running the snack bar, is overrun by girls grabbing food without paying.

After class, the girls try to leave without cleaning. Han-rim stops Ye-ri by force, warns that defying an inspector could get her killed and has the class scrub the floor. Seon-yeong worries that parents will complain. Soon an anonymous post accuses her of calling in the bureau to torment the girls.

That evening, Han-rim tells Hwa-jin that Seon-yeong seems afraid of her students. He orders a search of the students' social media for attacks on teachers, and Han-rim passes the job to Geun-dae by pulling rank. Later, Han-rim shows the class printouts of photos they edited to mock teachers and calls it defamation. Outside, some girls wonder whether the bureau came because of Mr. Ko's death, since nobody saw what he supposedly did, until Ye-ri joins them and changes the subject. Soon after, she posts a photo that lets commenters identify where Seon-yeong lives.

Seon-yeong weighs her future

Résumé in hand, Seon-yeong meets a college friend at a private academy to talk about leaving school teaching. The friend says students from Seon-yeong's school attend the academy and have heard what happened. She warns that the work is no easier and tells Seon-yeong to come back later if she still feels the same.

Ye-ri changes tactics. She asks Seon-yeong for help with an exam question, then joins the praise after a lively lesson on conditional probability. Han-rim warns that Ye-ri is manipulating her, but Seon-yeong welcomes the change and thanks the bureau. Ye-ri then apologizes and proposes a joint livestream to show they are on good terms. She suggests Seon-yeong also speak out about the bureau.

Hwa-jin takes Seon-yeong out of class and asks how long she will let the students get away with it. She shows him a forum post with her photo that reappears every time it is removed. She says she fears ending up like Mr. Ko and admits she is afraid. Hwa-jin tells her that his fiancée, a teacher like her, was murdered by a student two years ago. A memory follows of him and Ga-yun laughing through a wedding photo shoot. Then, in the memory, Hwa-jin tells Ga-yun he is there and thanks her for waiting, with Gang-seok weeping nearby, as a machine's beeping becomes a single tone.

Hwa-jin says he is not there for Seon-yeong's sake: "I'm here for the children." The bureau came because students from her own homeroom wrote asking for help. Park Su-jin, Kang Min-seo and others write that Ye-ri's posts about her are lies and beg the bureau to protect her. Hwa-jin says the bureau's help is temporary and only teachers make a lasting difference. He asks her not to give up yet.

Back in class, Seon-yeong turns down Ye-ri's livestream and calls her to the blackboard. Ye-ri refuses and mocks her. When Han-rim starts to step in, Seon-yeong tells her this is her class. Ye-ri is hauled to the front, and when she still refuses, Seon-yeong strikes her palms with a stick. Seon-yeong apologizes to the class for letting things get this far, promises to punish bad behavior every time and keeps everyone in the room until Ye-ri solves the problem. When Ye-ri writes the answer, Han-rim cheers Seon-yeong's name.

Ye-ri loses her audience

Furious, Ye-ri starts a post exposing a new abuser at her school, but the upload fails. Her posts delete themselves. Her accounts share the unedited footage of her accusation against Mr. Ko, in which she gloats that he is about to be canceled, along with private clips of her admiring her looks. Then the account is suspended at the government's request. Hwa-jin credits Geun-dae, and Han-rim announces a welcome party for herself.

As posts call Ye-ri a murderer and reveal her home, Seon-yeong is asked to check on her. When Ye-ri turns up at her door, Seon-yeong invites her in and asks whether she has eaten. Ye-ri says it should have been Seon-yeong instead of Mr. Ko, blames her for his suicide and calls teachers hypocrites. Saying she may as well die, she comes at Seon-yeong with a knife.

In the struggle, Hwa-jin goes over the balcony saving Seon-yeong and lands on a parked car. Inside, Geun-dae reminds Han-rim of the patience rule. Han-rim overpowers Ye-ri, and Han-rim's hand is left bleeding. She tells Ye-ri she will not kill her: "Live long, but repent." Ye-ri breaks down sobbing.

On the street, Han-rim tells Hwa-jin he has fallen from greater heights in training. The bleeding Hwa-jin says he promised to protect Seon-yeong. Then he asks for a stapler.

Word spreads about the Minister's daughter

At the Ministry of Education, Gang-seok announces that after the cyberbullying at Soyeon Girls' High, the bureau will suspend every account found trolling teachers. Elsewhere, a group of officials learns that the murdered teacher was a congressman's daughter, a fact her family kept private. One says Gang-seok hid it because her death would have become a political issue, and a call goes out to the press.

Alone, Gang-seok reads old messages in which Ga-yun teased him about eating cup noodles, then his own notes to her after her death. He is crying when Geun-dae sends him a link. In it, a speaker says the bureau was created after a young teacher's death two years ago, and that she was Gang-seok's daughter and Hwa-jin's fiancée. Every case so far has targeted students, the speaker says, from Ryu Jun-hyeong at Daehan High to Guun High-Tech High School and Soyeon Girls' High. The speaker calls the bureau a personal vendetta.

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