As our daydream continues, Ki Hyung and Han Byul sit in an auditorium listening to a cello player. Soothing music drifts through the air as father and son exchange a smile before turning their attention back to the talented musician. Ki Hyung closes his eyes and absorbs as much of the peaceful moment as he can. Later, in his office, it appears as though Ki Hyung is packing up his office. He fills boxes with books and files. He pauses as his eye catches the framed photo on his desk. It is a picture of his team during happier times. He carefully lifts the photo from its place and looks stoically at the smiling faces on its surface. His wife had cooked dinner that night. He remembers the meal and the feeling of family. Cheif Baek comes into his office and immediately hands Ki Hyung a file folder. He simply says “we have received an order from the Justice Department.” The two men sit across from one another and Ki Hyung listens as Cheif Baek explains that the death penalty has been reinstated in Korea and that executions will resume almost immediately. The decision was made because the occurrence of violent crimes has risen at a dramatic rate in the last ten years. The government hopes to slow violent crimes using the death penalty as a possible outcome. The NCI team is being called upon to close a multiple murder case before the criminals are executed for previous convictions. The team has forty-eight hours.
The regional news is full of reports about the killers to be executed. It is also full of live video of protesters against the death penalty. One reporter gives us the details of the case. A total of twelve women, all in their twenties, were brutally murdered by Jo Young Hoon and Ahn Yeo Jin. They are a couple who murdered together. They were convicted and both will die within hours of one another now that the death penalty has been reinstated after twenty years. NCI will try to discover if the pair is guilty of any additional crimes and if there are any more victims who require justice. Several days prior, remains were found at a construction site. The condition of the remains and the manner it was buried indicate that it is possible the killer couple is responsible. Ki Hyung tells Hyun Joon and Min Young to go to the home where the original twelve victims were found. When they finish with their search, they should meet the rest of the team at the prison.
As the giant NCI bus races to the prison, Ki Hyung and his team discuss the case. Ahn Yeo Jin had confessed to killing her two-year-old son but did not admit involvement in the murders of the twelve young women. Once she went to prison, she stopped talking to investigators and reporters. Hyun Joon and Min Young are having a similar conversation as they make their way to the killer couples former home. Jo Young Hoon was quite the opposite from Ahn Yeo Jin. He enjoyed talking about his crimes. Min Young says that the press dubbed Yeo Jin “Cold Witch” for her silence about the murders but also because she was able to murder her own child as well as bury twelve women on her property. Hyun Joon is more focused on the future than the past. If there are any more victims, their cries for justice will die with their killers if NCI cannot get any more information from Yeo Jin and Young Hoon.
At the jail, we follow Yeo Jin as she is lead from her regular cell to solitary confinement. When they arrive at her new cell, the warden asks her what she would like for her last meal. She meekly asks if she could see the last full moon instead of having the last meal. The warden says that it is against the rules. In the men’s unit, Young Hoon is led in a similar fashion to a solitary confinement cell. He smirks as his handcuffs are removed and he practically swaggers into his new cell as if he is going through a dance club door.
The NCI team arrives at the prison and they set up their command center. Lee Han, Sun Woo and Ki Hyung brief the other detectives and prison personnel about the case. Young Hoon had numerous photographs at his home that indicated he had tendencies similar to a pedophile. In the photographs, his victims were dressed in clothing that was childlike. It was also concluded that Young Hoon suffered from sexual dysfunction. Yeo Jin seemed to be a hybristophiliac, and was exclusively attracted to criminals.
Hyun Joon and Min Young arrive at the killer couples former residence. Yeo Jin had lured the women to their home with an advertisement searching for an assistant to an architect. Hyun Joon and Min Young move inside the house to search for more clues. Once inside the house, Hyun Joon points out the locations of Young Hoon’s work bench and torture room as well as the area in the floor where the bodies were buried. He tells Min Young that the wounds on the bodies matched with Young Hoon’s work tools. The case file indicates that Young Hoon was abused as a child and Min Young wonders what kind of childhood Yeo Jin must have had. Yeo Jin’s mother refused to speak to the police but she may have changed her mind since her daughter will be executed soon. Min Young and Hyun Joon decide to speak with Yeo Jin’s mother.
Ki Hyung meets with Yeo Jin in her cell. There are paintings on the wall. Ki Hyung compliments the artwork and Yeo Jin smiles and tells him that she’s had lots of time to paint. She then cuts to the chase and says she understands that Ki Hyung has something he wants to ask her. He tells her that it is time to let the victim’s families know why they had to die.
Hyun Joon and Min Young arrive at Yeo Jin’s mother’s home. Hyun Joon explains the reason for the visit when the old woman comes to the gate. She plainly states that Yeo Jin is her daughter, and that she had a scumbag for a husband and that she buried the women under their home. “What more do you need to know?” Fearing that Yeo Jin’s mother will refuse to talk with them, Hyun Joon lies and says that “Yeo Jin has promised that she would tell NCI why she killed the women.” Min Young stays quiet, in hopes that Hyun Joon’s gamble will work. Yeo Jin’s mother allows them in and they sit around a small table on the floor. Min Young asks about Yeo Jin’s childhood and her mother explains that everything was normal until she met “that scumbag”. Hyun Joon asks if Yeo Jin was abused by her father. Her mother admits that her husband was strict on Yeo Jin. Hyun Joon asks the question again and this time Yeo Jin’s mother says that it was she and not Yeo Jin that received the brunt of her husband’s abuse. She had nowhere to go with her daughter and so she remained in her abusive marriage. Hyun Joon asks Yeo Jin’s mother if she is the one who reported Young Hoon’s crimes fifteen years earlier. She says that she isn’t the informant but she knows who is. Yeo Jin’s mother stands up and moves to a set of mostly empty bookshelves. She pulls a letter from one of the shelves and gives it to Min Young. The mailman brought it to her that very morning.
At the prison, Yeo JIn is moved from her cell to an interview room. On the way, she and her guards encounter Young Hoon and his guards in a hallway. They have not seen one another since the trial. Young Hoon immediately begins to rave about their names being remembered for eternity and how execution is their fate. His guards drag him away as he screams victoriously about their ability to kill. Yeo Jin turns to Ki Hyun and asks him point blank if he arranged for her to bump into her former husband. She then asks if he found out anything new.
Sun Woo interviews Young Hoon. She tells him that he has been classified with antisocial behavior. He corrects her and says his diagnosis is sexual dysfunction. He then compliments her beautiful smile and notes that she is not smiling. Sun Woo is strictly business and asks him if there are any more victims. Young Hoon asks what he will get if he tells her. Sun Woo says that he will get to provide the families with closure. He giggles at the idea.
In another interview room, Ki Hyung speaks with Yeo Jin. He notices her fiddling with her handcuffs and requests that they are removed. Yeo Jin thanks him for his assistance since the cuffs limit her ability to grab a brush. Ki Hyung asks her what is the best thing about drawing. “Freedom” is her single word reply.
Na Hwang receives a phone call from Min Young who asks to speak with Ki Hyung right away. Na Hwang connects them and Min Young explains that she has a letter received by Yeo Jin’s mother. Ki Hyung asks Min Young to read it. As she does, Ki Hyung repeats all that she says so that Yeo Jin can hear. They are her own words written to her mother. In the letter, Yeo Jin says that she understands her mother now and regrets not doing her duty as a daughter. Hearing her personal letter read back to her sends Yeo Jin into a rage. She lunges towards Ki Hyun who easily grabs her wrists and keeps her from knocking the phone from his grip. The guards take her back to her chair and begin to replace the handcuffs. Ki Hyung assures the guards that everything is fine. He asks Yeo Jin directly what duty she didn’t perform. He then asks her why she is trying to receive the death penalty for something she didn’t do.
After the interview, the team discusses Yeo Jin and Young Hoon’s relationship. They conclude that Young Hoon would create his own world when he killed his victims and if Yeo Jin had witnessed any of the crimes she would be dead as well. One of the detectives interjects that Yeo Jin had indicated that she killed the women as well as her own son. Hyun Joon and Min Young arrive with the letter and explain that it was Yeo Jin who informed on Young Hoon because she suffered from endless guilt about the murders and her inability to stop them. Lee Han believes that Yeo Jin made a false confession because she was being controlled by Young Hoon. Ki Hyung watches the monitor of Yeo Jin’s cell and notes that she protects her paintings like she might protect a child.
Meanwhile, outside the prison, dueling protesters shout at one another while reporters give up to the minute commentary on the death penalty case. Hyun Joon asks Na Hwang to pull Sun Woo out of the interview room since it seems that she is getting nowhere with Young Hoon. Hyun Joon takes her place and Young Hoon complains a bit about having to deal with a man instead of a woman. His desires are quickly granted when Min Young enters the room. He quickly perks up and asks Hyun Joon who the beautiful woman is. Min Young introduces herself and remains as stone cold as Sun Woo was. Young Hoon goes into full creeper mode and offers a greeting to Min Young that would make any girls skin crawl. Hyun Joon tells him to sit down and then so does Min Young. They are clearly not interested in dealing with his creeper bulls**t.
While Na Hwang looks over a file on Yeo Jin, Ki Hyung speaks with her in an interview room. She apologizes for her previous outburst and compliments Ki Hyung on his smile but notes that he doesn’t use it often. A guard places Yeo Jin’s paintings on the table next to Ki Hyung. He looks at the first painting and remarks on the gently flowing river. He looks at the second painting and says that the child in the drawing is running freely. The third painting holds a dozen roses. He tells that she has painted one rose for each victim and then he tells her that she is wrong. The painting is missing a rose for the thirteenth victim. He explains that the number of flowers is incorrect because she didn’t know about the thirteenth victim. In fact, she didn’t know about any of them. Her work record shows that she could not have been the one to lead the women to their deaths because she was working at the college all day while her husband was killing. Ki Hyung asks her why she submitted a false confession.
In Young Hoon’s interview room, he is trying to make a deal. He says that he will tell them about other victims that he has buried if he can have something in return. Hyun Joon asks him if that means that there are other victims? Young Hoon says he will tell them what they want to know if they will allow him to smell Min Young’s hair. Hyun Joon tells him to quit fooling around and then to his surprise, Min Young agrees.
In Yeo Jin’s interview room, Ki Hyung asks her why she lied about killing her son. She asks him if he has a child and he says that it has nothing to do with the case. She asks again and he tells her to quit changing the subject. Meanwhile, Young Hoon is sniffing at the air around Min Young like a dog on a too short leash. He fights against the guards to get as close as he can to her but the guards know that this dog will bite if they let his leash out a bit too far. The guards finally return him to his chair. He pants like a rabid animal and smiles when he realizes that it is his turn to give something back.
In Yeo Jin’s interview room, Ki Hyung continues to press her about her son. He asks how old he would be if he were alive. Yeo Jin begins her own line of questioning when she notices Ki Hyung’s wedding ring. She asks him about his wife and he asks her why she is protecting Young Hoon. He says that he believes that she is innocent but she counters that all people are guilty. She asks him again about his son and he finally relents and admits that his son is six. She asks if he has a photo and he admits that he doesn’t carry one. Yeo Jin understands why he does not. He wants to protect his son. Ki Hyung asks if she committed murder in order to protect her son and then asks where she buried him. Yeo Jin replies that her son is in a safe place.
Young Hoon acts as if he is going to tell Hyun Joon about his other victims but then he begins to laugh and says that there aren’t anymore. Hyun Joon turns to Min Young and then turns to leave. He then turns back to Young Hoon as if he’s forgotten to tell him something. “Did you know the Justice Department has postponed Yeo Jin’s execution? They don’t have any evidence that she killed her son.” Young Hoon begins to brag about knowing what really happened. Hyun Joon is unimpressed and casually tells the guards to take Young Hoon away. As the guards take his arms, Young Hoon jumps to his feet and turns the table on its side, all the while screaming “Do you want me to tell you where Si On is buried?? Do YOU!!!” Hyun Joon finally has Young Hoon where he wants him.
Lee Han and Sun Woo go to Young Hoon’s home to locate Si On’s body. They notice a balcony that overlooks the area as well as an arched doorway that matches the one in the workshop. Searchers find a skull in the underbrush. The skull belongs to a nineteen-year-old woman. It doesn’t make sense to them that Young Hoon would give them information about another victim since control and secrets are his greatest power. Ki Hyung goes to Yeo Jin’s cell and asks her about a girl she once tutored named Choi Seol Ah. Yeo Jin remembers the girl and says that she didn’t have much talent. When Ki Hyung tells her that they have found her remains under the garden gate, Yeo Jin looks at Ki Hyung in shock.
Hyun Joon goes to Young Hoon’s cell to tell him that the body they found was not Si On’s. Young Hoon casually smiles as Hyun Joon tells him that the girl was barely out of high school. Then, as if it had temporarily slipped his mind, he says the victim’s name. “Seol Ah…..She was pretty like her name.” Hyun Joon draws in a deep breath in an attempt to control his anger. He asks Young Hoon how many other girls he’s buried. Young Hoon calls for the guard and says he wants to be alone. Hyun Joon lets him know that it isn’t over yet.
Hyun Joon looks at the painting in Yeo Jin’s cell. He believes that she painted the picture of the boy based on his actual age. Yeo Jin becomes increasingly uncomfortable and she calls for a guard to come and get Ki Hyung. Ki Hyung quickly returns to the team area and watches his interview with Yeo Jin. He is reminded of the story of Moses in the book of Exodus. It is the story of a mother who hides her child from a killer and the lengths she goes to for him to remain hidden. Of course, Lee Han can quote the story, chapter, and verse.
Yeo Jin watches the sunset through her prison bars. Somewhere in the prison, guards prepare the execution chamber. Meanwhile, the NCI team furiously tries to find the evidence they need to clear Yeo Jin of her charges. Ki Hyung asks the warden for five minutes in Yeo Jin’s cell while Hyun Joon goes to Young Hoon’s cell for a final face off.
Yeo Jin has been granted her request to view the moon. She thanks the chief for granting her request and then recalls telling a story to her son about the moon. In Yeo Jin’s cell, Ki Hyung tears everything apart looking for a clue to her innocence. Just when he thinks he has reached a dead end, he takes the painting of the boy from the wall and finds a photograph hidden behind the painting. Ki Hyung takes the photo to Na Hwang. Min Young will release the photo to the press hoping they can help in locating the boy.
Young Hoon prepares for his execution and changes from prison blues to the white uniform of a condemned man. Outside the cell, a priest offers him absolution but he answers that he has already found his own peace nineteen times, and each of them was prettier than the Lord. He says the last sentence while looking directly at Hyun Joon. Hyun Joon faces him and asks why he wants to hold on to his secret until the very end. Young Hoon’s answers and says that Hyun Jonn “already knows why.” Young Hoon walks towards the execution chamber with guards by his side. Hyun Joon looks at the prison official and tells him that Young Hoon has just admitted to six more murders. The guard rushes to the execution chamber while Hyun Joon runs to find Ki Hyung.
In Yeo Jin’s cell, she carefully combs her hair and then reaches for the painting of the boy in the field. She turns the painting over and finds the photo of her son is gone. In the execution chamber, Young Hoon is tied to a chair underneath a noose. Black curtains open to reveal those that will witness his execution. He is asked if he has any last words and he laughs like a crazy person at the question. Hyun Joon enters the viewing room. Young Hoon notices him and smiles broadly and announces “I won”. Hyun Joon’s face is deadly serious as he lifts a photo to the window for Young Hoon to see. “Do you see?” he asks Young Hoon. “It is the son that you thought was dead. Your illusion is over. You have lost” Young Hoon screeches in disbelief and then begins to scream that Yeo Jin is coming with him. He screams that Hyun Joon will never find the bodies. “You’ll never know!” As a hood is placed over his head he insists that he has won and that Yeo Jin is still his. A noose is fastened around his neck while he rages. Two guards push a red and green button simultaneously causing the floor beneath Young Hoon to fall away.