The third episode of Dear X commences with Ah-jin, captivated by the sight of a man, Choi Jung-ho, a former baseball player, taking down a thief on the street. Her fascination with him is palpable. A voiceover from Joon-seo narrates that this moment marked the beginning of her descent into the depths of hell. Soon, Ah-jin lands a part-time job at Jung-ho's cafe, drawing the attention of patrons who marvel at her beauty. Her photos go viral, even catching the eye of Mi-ri.
Ah-jin discovers that Jung-ho's career was cut short due to an injury inflicted by a player named Kwak Eun-hyeok. As she works, the CEO of PB agency, Im Seung-ryong, enters and speaks with Jung-ho, prompting her colleague to whisper that Jung-ho might be offered a new contract.
Meanwhile, the number of stalkers in the vicinity has spiked. One such individual sees Ah-jin's photos and follows her home after the store is about to close. Yoo-sik, Ah-jin's colleague, sends him away, but he persists. Joon-seo later finds Ah-jin hitting the stalker with a rock and berates him for arriving so late. She asks him how far he would go for her, and his answer—anything except murder—falls short of what she seems to be looking for. As she departs, Joon-seo calls an ambulance for the man and tosses the rock into a river.
Ah-jin returns home to overhear her father on the phone discussing the sale of his daughter. When she tries to sneak up on him, he threatens to kill her and leaves. Back at work, Jung-ho notices the neck injury her father inflicted and worries about her well-being.
Elsewhere, Joon-seo witnesses Sun-gyu selling a spy camera to someone else. Sun-gyu catches Joon-seo filming him and they engage in a physical altercation. Sun-gyu passes out, and Joon-seo picks up a brick but is unable to bring himself to kill him. The police soon arrive and take both of them away.
Ah-jin observes it all. At the police station, she fabricates a tale, claiming Joon-seo to be her stalker who inflicted the injury on her neck. She even deletes the footage of Sun-gyu from Joon-seo's phone. Later, Ah-jin informs Joon-seo that he clearly lacks the aptitude to care for her father.
Ah-jin arrives at work, sporting another bandage. Jung-ho is immediately concerned, and Ah-jin informs him of her stalker. He decides to drop her off at home for a few days. As she approaches her apartment door, Ah-jin discovers a dead mouse in a box. The stalker lurks nearby, and Jung-ho gives chase. But he escapes. Jung-ho leaves a baseball bat with Ah-jin and departs.
Later, Yoo-sik spots Ah-jin in a convenience store. He also sees the stalker from earlier, but it seems Ah-jin isn't intimidated by him. That night, Ah-jin ransacks her entire apartment.
The next day, Mi-ri approaches her again and asks her to sign with the agency. Ah-jin admits she's interested but has something to attend to. She then tells Jung-ho that her apartment was trashed while she was out. She pretends Joon-seo is out of town, which prompts Jung-ho to offer his own place for her that night.
As Yoo-sik is about to tell Jung-ho that he saw Ah-jin and the stalker at the convenience store, Ah-jin cuts her hand to create a distraction. In the meantime, Ah-jin also messages her father, instructing him to come to her apartment at 8 to pick up the money.
Jung-ho sends her to his house in a cab, but Ah-jin informs him she's going to her place to retrieve some things. She arrives to find her father waiting for her. She gifts him a beanie and makes him wear it. When she doesn't give him the money, he starts beating her but not before she makes a call to Jung-ho. Jung-ho rushes over and engages in a fight with Sun-gyu, ultimately hitting him in the head with his own bat.
The final scene is slightly perplexing. We see Ah-jin swinging the bat as well. Sun-gyu lies dead on the floor. Jung-ho runs down the stairs while Joon-seo, who has been released from jail, runs towards Ah-jin's house. The episode ends with Ah-jin making a 911 call and saying her father is bleeding, all while laughing maniacally.
