In the fourth episode of "Phantom Lawyer," the story unfolds with I-rang's mother and a priest visiting his office. His mother has come seeking her late husband's talisman, as she believes her visit to the shaman who once owned the office might be the reason why I-rang can see ghosts. The priest is also trying to unravel the mystery and is looking for the incense I-rang had mentioned. They both agree that to understand everything, they need to find the shaman first.
Meanwhile, Na-hyun bandages I-rang's arm after the accident. She questions why he was at the entertainment company, and he lies that he is a fan of one of the idols. Na-hyun is not convinced and decides to check the CCTV footage. At the same time, I-rang goes through the footage from the truck's dashcam to regain his memory of what happened when he was possessed.
It becomes clear that Su-a ran after Jong-seok because his ringtone was what she heard when she was pushed off the roof. An online search about him reveals that he has been accused of copyright infringement several times. Bong-soo suspects something fishy about him, but Su-a remembers him as a kind person who invited them to his house and bought them meals.
I-rang logs on to Su-a's phone account, and its location shows Jong-seok's house. Bong-sun suggests involving the police, but I-rang wants them to find more evidence before doing so.
Elsewhere, Do-gyeong visits Gi-cheol in jail. He is furious that Gi-cheol decided to keep the hard disc after being given a job that led to the loss of the case. Do-gyeong gives him a script of exactly what he will say in court to ensure that he will not be implicated. Gi-cheol is terrified of Do-gyeong and blames everything on I-rang, insisting that he should look into him.
He recalls that I-rang was initially timid and believed he could protect her, but suddenly his demeanor shifted, and he became Gang-pung. Do-gyeong enlists his assistant to delve deeper into the matter. As the priest continues his search for the shaman, I-rang, Su-a, and Bong-soo sneak into Jong-seok's home to investigate. I-rang discovers that Su-a is stunned to see Jong-seok using her music, claiming that writing songs is a mere formality. Suddenly, a message on Su-a's phone gets Jong-seok agitated. He calls someone on the phone and asks to meet, since a third party knows about Su-a's songs, meaning he cannot use them.
Su-a assumes that the person Jong-seok called is Abel since she also knew that Su-a could write songs. They believe that Abel helped Jong-seok get her phone, and the person in danger is Emma. Before Jong-seok can leave, Na-hyun arrives to ask about I-rang. Na-hyun knows I-rang is in the house because she saw his truck when she arrived, so she waits for him after Jong-seok leaves. She listens to his account of events leading to Su-a's murder but wants to know how he obtained his information. I-rang promises to tell her everything honestly but first asks for her help to stop Abel from committing any more crimes and to save Emma.
The situation takes a different turn when Na-hyun sends I-rang a list of the final scorecard for the trainees before their debut. The killer might not be Abel but Emma, as she had the most to gain from Su-a's death. The company wanted a 7-member girl group, and Emma finished 8th. The only way she could debut is if one of the seven girls before her pulled out. Emma confirms this suspicion when she attacks him with a taser he had given for protection against Jong-seok, who had just arrived at the meetup point.
Jong-seok tries to escape but is stopped by Bong-sun. Emma is also cornered, and when she gets caught, she reveals everything. She was never Su-a's friend. Emma hated Su-a so much because everything she worked so hard to achieve came too easily for her. Before joining the company, Emma was among the least talented, but she soon took over. She was a talented dancer and could sing and even write songs. Even when she lost her cool with other trainees, they easily forgave her and were eager to become her friend.
Emma had blackmailed Abel and the other trainees in their group to have Su-a kicked out, and it worked. On the day she died, Emma had followed her to the rooftop, wanting to see her crying hopelessly, but instead, she saw Su-a smiling. That's when she realized that Su-a was not defeated, and she would get back up someday and still surpass her. Emma pushed her off the roof, and Jong-seok witnessed it. Emma threatened him, and because she had the power to make her threat real, since her father was very rich, Jong-seok chose to become a co-conspirator and profit from Su-a's songs. Emma and Jong-seok are at rest, and Su-a has one more unfinished business to attend to: meeting her mother.
The scene becomes emotional here as it turns out that her mother did not abandon her. When Su-a was only a year old, she was diagnosed with a disease that interfered with her sight. She sent her to her grandmother to protect her. As her last wish, Su-a donates her organs, saving four people, including her mother, who gets her eyes. With all her attachments resolved, the priest burns her talisman, and she finally rests in peace.
When Na-hyun confronts I-rang to know where he gets his information, he tells her he can see ghosts, but she does not believe him. When So-hyun died, Na-hyun gave up her dream of becoming a singer and became a lawyer instead. Na-hyun presents a high-stakes case to Do-gyeong since his father has recovered and will be coming back to the country soon. If she wins, it would be the perfect gift for the chairman. If she loses, she will take the blame, and Do-gyeong can fire her.
At the end of the episode, I-rang fully accepts his role as a Phantom lawyer as a new ghost shows up in his office.
