: Yeon-jin discovers that Dong-eun has been living in an apartment directly across from her own home. She breaks in and is horrified to find a "revenge wall" covered in photographs of herself and her friends.

The following events mark the climax of the first half of the series:

: The episode ends with a double shock: Yeon-jin is caught in Dong-eun's apartment by her own husband, Do-yeong, while Yeo-jeong discovers that the body of So-hee (a previous bullying victim) has vanished from the hospital mortuary. Critical Reception and Discussion

: Desperate to save her upcoming marriage to a wealthy family, Hye-jeong grovels at Dong-eun's feet. Dong-eun blackmails her into reporting Myeong-oh as missing to the police, which infuriates the drug-addicted Sa-ra.

notes that the episode effectively sets the stage for Part 2 by highlighting how Dong-eun has successfully infiltrated every aspect of her tormentors' lives.

: Dong-eun meets Jae-jun on school grounds, where she slaps him after he provokes her. She reveals that she knows he is Ye-sol’s biological father and uses this leverage to turn him into a reluctant ally.