Dong Chi remembers the day Han Byul died, but Yeol Moo still thinks that he killed her brother.
During an investigation Kang Soo killed a criminal for the first time.
Yeol Moo goes on the balcony after Dong Chi. She takes out the piece of paper, handed over to Dong Chi and asked him why he killed her brother. But the question is wrong. She should have asked if he killed her brother. Dong Chi corrects her and answers that he didn’t kill Han Byul. Each of them goes to their rooms.
In his room, Dong Chi remembers the day Han Byul died. That day Dong Chi received his report card and wanted to show it to his father. Because his father wasn’t home, Dong Chi went to the factory where his father used to work. A strange man was there. That man ripped Dong Chi’s report card and throw it away. Realizing what is going on, Dong Chi wants to leave. He bends down to pick the ripped report card and he sees something. A child was hiding! That child picked the other side of Dong Chi’s report card and wrote on it “Please save me!”. That child was Han Byul. He saw something that he shouldn’t have and the strange man was looking for him.
Dong Chi goes out, but he doesn’t leave. The man came outside to look for the boy and Han Byul took advantage of it and ran away. But the man caught him and took him back inside. Hearing Han Byul screaming, Dong Chi goes back in the factory and hits the man with a board. The man was trying to drown Han Byul. Dong Chi takes Han Byul in his arms and runs away. Outside was snowing. While he was running with Han Byul in his arms, Dong Chi slipped and fell. He was unconscious for some time. When he woke up, Dong Chi went to look for Han Byul. But no one was there. Han Byul disappeared. The strange man and his car were gone. Dong Chi’s bag and bike were gone. The only thing left, next to Dong Chi, was one of Han Byul’s shoes. That day always haunted Dong Chi. Until that day he wanted to become a doctor, but since then he became a prosecutor.
The next morning, Yeol Moo left early. When he comes to the office Dong Chi tells her that the grandmother will kick her out if she will leave without eating breakfast again.
Dong Chi:”Do you want to get kicked out?”
Yeol Moo is rude with Dong Chi. She still blames him for Han Byul’s death and her only evidence is the piece of paper on which Han Byul wrote “Please save me!”
Later Dong Chi and Yeol Moo arrived at the crime scene of their new case. Both Yeol Moo and Kang Soo react the same way in front of dead bodies. They can’t watch dead bodies and throw up when they see it.
A woman was found dead in a toilet. They need to investigate her death and see if it’s murder or suicide. There is a difference on the marks if someone is strangulated or if that person hanged herself. On this case a scarf was used, so the marks on the victim’s neck aren’t clear.
Kang Soo and Yeol Moo went to investigate what Dong Chi asked them. On their way they seem a little close. Seeing Kang Soo and Yeol Moo like that an idea comes into my head, what if Han Byul didn’t die. What if Kang Soo is Han Byul?
When Dong Chi saw the yellow scarf she asked if next to the victim there was a ring. This case reminded him of an old case, where a criminal used to kill his victims with a yellow scarf and put on them a bamboo ring.
While the prosecutor’s office was investigating the dead woman’s case, Dong Chi received a text from an informer about someone who will bring drugs into the country. They go to the harbor and check everyone that was on the boat that will bring the drugs in.
The drug dealers know what they were doing so they used an old man to distract the police attention. Prosecutor Lee Jang Won, Yoo Dae Gi and Yoo Kwang Mi followed the old man. They realized that he was just a distraction, but they also checked the drugs bag that was with the old man.
Meanwhile, Dong Chi and his team remain at the harbor. While looking at the surveillance camera, Dong Chi noticed a truck entering the boat. The truck it’s suspicious and he sends Kang Soo to check. Kang Soo confirmed that the truck driver has the drugs and followed him. Dong Chi and Yeol Moo went to after the truck. The driver is surrounded, but he fights back. he has a knife and cuts the drug bag. There is no evidence now.
The truck driver knows Dong Chi. He tries to attack Dong Chi, but Kang Soo stepped in. Both Kang Soo and the drug dealer fell into the water. When they come out, the water in red around them, the drug dealer is injured. He is taken to the hospital, but the doctors can’t help him.
Socked, Kang Soo went to Jung Chang Gi.
Kang Soo:”I killed someone!”