Yeol Moo and Dong Chi found Han Byul’s shoe at the factory where Han Byul’s body was found. Also at the factory, Dong Chi saw Han Byul’s killer.
Kang Soo is shocked to find out more about the time he and Han Byul were kidnapped. He blames himself that Han Byul was killed instead of him.
Dong Chi found out that Moon Hee Man and Jung Chang Gi know each other. They went to school together and after they finished their studies one became a prosecutor and the other one a lawyer.
Dong Chi goes to Jung Chang Gi’s house and finds a book. Inside that book, Dong Chi saw a piece of paper with the article about the hit-and-run accident from the day Kang Soo disappeared.
Returned to his house, Dong Chi saw Jung Chang Gi, who will stay with them for the night. He can’t stay at his house. That night Jung Chang Gi slept in Kang Soo’s room and Kang Soo told Jung Chang Gi that he met a man who called him Seo Tae Won. Kang Soo said that the man who called him Tae Won knew him and his mother. Shocked, Jung Chang Gi pretends to be sleeping.
In his room, Dong Chi tries to find out any connection between Moon Hee Man, Jung Chang Gi and the hit-and-run accident. Suddenly he hears noise and goes outside. Jung Chang Gi was leaving. Dong Chi follows him and outside he calls Jung Chang Gi “senior”. Jung Chang Gi stops. That night Jung Chang Gi told everything to Dong Chi. That night of the accident, Jung Chang Gi and Moon Hee Man were returning to the special unit with evidence. Suddenly a woman appeared before them and the accident happened. Moon Hee Man sent Jung Chang Gi back with the evidence, while he remained to take care of the accident. Later they found out that the dead woman had a son.
To be able to catch the criminals that the special prosecution unit was investigating, Moon Hee Man and Jung Chang Gi were supposed to cover up the hit-and-run accident for six months. Because he was feeling guilty and was about to confess, the special unit sent Jung Chang Gi away for a while. During the time he was out of the country, the dead woman’s son was adopted by Kang Soo’s grandmother. Jung Chang Gi’s guilt made him return over and over again to the house that took the boy. He wanted to see what the boy was doing. One of those days he went there, the boy saw him, but he didn’t recognized him. That day the boy took Jung Chang Gi’s by hand.
Also Jung Chang Gi confessed to Dong Chi that he was the driver the night Kang Soo’s mother died.
Early in the morning Dong Chi is vacuuming. The noise woke up Kang Soo and Yeol Moo.
Yeol Moo:”You didn’t go to Daegu?”
Kang Soo:”Let me sleep!”
Dong Chi was inspired. He isn’t leaving, he is just taking advantage of all the vacation days he didn’t took. In the end Kang Soo is the only one that is going to work. When Kang Soo arrived to the office, chief Moon took Kang Soo to work for him.
While Kang Soo was talking with chief Moon about the cases chief Moon took from Dong Chi’s office, Park Soon Bae arrived. Chief Moon called him for a declaration. Trying to scare Moon Hee Man, Park Soon Bae tells chief Moon that he knows Kang Soo, he even calls Kang Soo on his real name, Seo Tae Won.
Dong Chi and Yeol Moo went to the factory were Han Byul’s body was found. That factory is cleaned up now, the owner took out the equipment and Dong Chi thinks that they could find new clues about Han Byul and Kang Soo there. He takes Yeol Moo to the place where Han Byul’s body was found and lets her look around there to see if she will find anything. The same time Dong Chi will search in another part of the factory. When Dong Chi was walking on the path he did with the little boy in his arms, he realizes that someone is behind him. Dong Chi looks back and sees a man. It’s the same man that was at the factory the day Han Byul died. Coming to his senses, Dong Chi runs after that man, but he lost it.
Yeol Moo never saw Dong Chi’s face like it was that day. Seeing Kang Soo’s kidnaper, made Dong Chi remember what he felt that day, he was scared to death.
Dong Chi:” Yeol Moo, just because you’re happy doesn’t mean the sadness leaves you.”
When they were about to leave, sad because they didn’t find anything, Yeol Moo saw Han Byul’s show and sock. Every time he was frustrated, Han Byul would’ve taken out his socks.
Someone send a package to Kang Soo. He opens it, but he got a phone call and closed the box again. Kang Soo went outside to talk on the phone. He asked the person form the phone why isn’t he laving with the family he was supposed to leave with. In a hurry Kang Soo printed a map of the place he disappeared too and went back to the office.
Kang Soo showed Yeol Moo and Dong Chi the place where he disappeared. On his way back home Han Byul had to meet Kang Soo, because Kang Soo disappeared from the police car that was taking him to his new family on the way Han Byul would have gone home.
The three of them realized that the person who kidnapped Kang Soo was confused and took the two boys with the same clothes. Kang Soo feels guilty. He thinks that Han Byul died instead of him. Yeol Moo runs away and Kang Soo runs after her.
Meantime chief Moo came to the office and took Han Byul’s case from Dong Chi. That night chief Moon met someone. The man that chief Moon met is Han Byul’s killer.