Tae Oh rushed to Gosan Station to meet Park In Kyu, who bribed him money. Sun Woo left Hyun Seo at the train platform but went back looking for her to hand over what she left behind. She found Hyun Seo's luggage unattended and looked for her.
As she went outside, police sirens, and people ran towards the other side where a man fell from the rooftop and died. Sun Woo approached the site and found her scarf with blood on it with the dead body. Dr. Kim came and convinced her they should leave the scene right away. Dr. Kim confirmed to her that a man died - it was Park In Kyu.
Tae Oh arrived home past midnight with a left stain in his suit and a scratch wound on his neck. Da Kyung saw it, but he moved fast and went to the next room to avoid her. The following day, Da Kyung answered Tae Oh's phone, and the other line was from the police station asking about her husband.
Sun Woo went to work puzzled about what happened to In Kyu. She met Dr. Kim in his clinic. She asked him why she was at the Gosan train station at that moment. Dr. Kim shared that he followed Tae Oh, and he saw him furious, leaving his building. Tae Oh led him to the Gosan station. When he alighted from his car, the incident occurred. He saw Sun Woo looking shocked and, at the same time, Tae Oh was leaving the station.
Hyun Seo called Sun Woo and asked for help to get a place to hide. Hyun Seo shared that she ran away from In Kyu after she bid farewell to him at the rooftop. She used the staircase to go to the ground floor. Tae Oh appeared and strangled her looking for In Kyu. Hyun Seo told him In Kyu's location, and Tae Oh left. In her fight with Tae Oh, he left his wedding ring and Hyun Seo kept it with her.
The detective visited Ye Rim to ask if she knew In Kyu and the scarf, which Sun Woo owns. Yerim is Sun Woo's neighbor who helped her when In Kyu harassed and broke Sun Woo's window. However, she did not recognize his In Kyu's face that night. Sun Woo reported to the police about the harassment and pointed In Kyu as the suspect. That case was left as an active case in the criminal department.
The detective visited Sun Woo at her clinic to ask about her scarf and her involvement. Sun Woo admitted that she's at Gosan Station that night with Hyun Seo and gave her the scarf. She did not know that In Kyu followed them or at the train station as well.
Sun Woo helped Hyun Seo hide from the police and Tae Oh. She is confused if Tae Oh killed In Kyu, and his ring may serve as evidence given by Hyun Seo.
Tae Oh confronted Sun Woo that both of them are suspect for murder and that they need to protect each other. Joon Young is being bullied at school as they talked about his mother and her connection with In Kyu's murder. Myung Sook warned Sun Woo to take precautions since the Gosan community is gossiping that she is the suspect for the case and that she might be a lover of In Kyu.
Ye Rim and Je Hyuk are about to finalize their divorce in court. They visited Sun Woo at her clinic to share the information Je Hyuk got from his friend. The video coverage at the train station on the night of the murder did not work. Someone manipulated the video, which leads to the police suspension that In Kyu did not die due to suicide.
Chairman Yeo instructed his secretary Lee Min to get the video coverage at the station and hide it from the police. Da Kyung met Tae Oh for dinner and she asked Tae Oh about the night in Gosan. They had a heated argument that made her leave the restaurant. Tae Oh ran after her and convinced her that he did not kill In Kyu. Da Kyung told him about the Gosan ticket receipt found in his pocket. She said to him that his bloodstain that night makes her think twice of what he did.
Hyun Seo felt restless waiting for Sun Woo's help in sorting In Kyu's case. She went to the clinic and followed Sun Woo on her way out. Sun Woo went to a restaurant and met Chairman Yeo and Dr. Kim. Hyun Seo was shocked to see them in one place and she lost trust in Sun Woo. She went to the police station and informed the detective of what she knew about In-kyus' death and Tae Oh as the murderer. The policemen picked up Tae Oh at his office to bring him to the station.
Hyun Seo called Sun Woo and told her that from now on, she would not need her help. She will solve the case on her own with the police.
Chairman Yeo has a hint about what happened to Tae Oh that moment since he missed his calls.
