Flashback…2005…fall…Do Hyun Soo faces Baek Man Woo and Gong Mi Ja . He notes their prison has been comfortable. Hyun Soo asks the question, why is the driver that hit him in a coma? Mrs. Baek leaves the room. Mr. Baek notes there were unintended consequences. Hyun Soo asks why they want him to assume their son's identify. Mr. Baek says his son may be gone, but he wants to keep the rest of their life. He just became head of surgery. Hyun Soo notes Mr. Baek doesn't want to lose the position. Mr. Baek agrees. Hyun Soo asks what will happen to him if he refuses. Mr. Baek states Hyun Soo will go to prison and he'll lose the new position. He suggests they help each other out. Hyun Soo agrees. Mr. Baek gives him a scrapbook about his son and directs him to study it. He tells Hyun Soo to break the friendships his son had. He admits Hyun Soo might struggle to fulfill the reserve duty training. Newly blond Hyun Soo gets and ID as Hee Sung.
Why the real Hee Sung is in coma wasn't answered. The father not wanting to lose his position and status because of his child's coma feels like an excuse not a reason.
Reporter Kim Moo Jin chides Hyun Soo for wanting his help to find Hyun Soo's sister. Hyun Soo points out Moo Jin's story made his sister an accomplice. Hyun Soo asks if Moo Jin believes he helped his father. Moo Jin asks how he plans to find the accomplice. Hyun Soo recalls Mr. Park showing him the fish charm and his assertion that his wife had an identical charm. Hyun Soo knows his sister was given the fish charm at his father's memorial service by the accomplice. Hyun Soo suggests if Moo Jin works with him, future successful stories will be forthcoming.
Detective Cha Ji Won tracks her husband through the tracking watch he wears. She wonders why he's visiting Moo Jin.
When Hyun Soo returns to bed, his wife asks where he went. He claims he went to his workshop. She says she can smell the car's air freshener. She claims she's not angry. Hyun Soo claims he got stuff out of the car for the workshop. Ji Won pretends everything is okay.
The next day Ji Won notes her husband has been in his workshop all day. Ji Won, Detective Choi Jae Sub and Officer Im Ho Joon are watching the gang. Their intended victim arrives. The gang sends someone to pick up the device left on the table. Ji Won stops the member and is shocked to see the young victim who lied his father hurt him to save his mother. The young victim rushes out. Ji Won follows. She gets him to stop and asks why he's doing this. The young victim declares he should have kept his mouth shut and runs away.
At the police station the young victim's mother admits her son has suffered since her husband when to jail. She leaves to search internet cafes at Ji Won's suggestion. Ji Won notes the young victim was right that if he'd kept his mouth shut his family would still be together albeit dysfunctional. She stares at her family photo. Team Lead Lee Woo Cheol arrives an announces the team has been chosen to investigate the Yeonju serial killer murders.
Hyun Soo works in his metal shop. Moo Jin calls to report her found Hyun Soo's sister. Hyun Soo asks if Moo Jin knew where his sister was all along. Moo Jin tells him 7pm is the meeting time. Hyun Soo asks Moo Jin to investigate the police report discrepancy that murder victim Jung Mi Sook packed a bag and left her husband after an argument. If so why did Mr. Park report his wife missing? Moo Jin agree that is odd. Hyun Soo tells Moo Jin to visit Mr. Park in prison and hangs up.
Do Hae Sue (Do Hyun Soo's sister) is surprised to find Moo Jin outside her class. He remembers her distress from the previous evening. He says there's something she need to know. He says he knows where Hyun Soo is. He claims he's fabulous.
Ha!
The team discusses taking the cases. Ji Won doesn't think investigation of a cold case will yield much. Detective Choi declares Hyun Soo is the logical avenue of investigation. Ji Won tells Team Lead Lee another team should take on the cold case. Everyone finds her position odd. Detective Choi notes she's preoccupied of late. He asks if she's working other cases on the side. Ji Won denies it. Hyun Soo calls her to report he'll be late. He claims he's meeting a colleague. Ji Won tracks him on the tracking locator app. She knows what he told her is a lie.
Hyun Soo arrives at 7pm. He enters the building that is abandoned. He sees his sister looking out the window. He walks to her. She turns. They lock eyes. He approaches. Hyun Soo says he didn't want to involve her in his life but he needs her help. He asks who gave her the fish pendant at their father's memorial service. Do Hae Sue throws herself at her brother and hugs him tight.
Flashback…a young Hyun Soo finds the foreman's body and his sister holding a knife. He asks if she killed him. She says she asked him to stop performing exorcism on him but he attacked her. Hyun Soo grabs the knife and smears the blood on him. Do Hae Sue tells him not to do this. Hyun Soo tells her to live a normal life. He says he'll never be able to do that.
Do Hae Sue sobs that Hyun Soo should hate her for the path of pain his life took. Hyun Soo tells her it was his choice to walk that path. She sobs. He holds her.
Baek Eun Ha (Jung Seo Yeon) (Hee Sung's daughter) is all smiles as her grandmother (fake but she doesn't know that) cooks for her. She wants Mrs. Baek to feed her. She complies. Eun Ha declares it is yummy but her father's food is better. Mrs. Baek is pleased. Mr. Baek finds them and isn't happy. Eun Ha greet her grandfather. Mr. Baek tells his wife they need to talk.
Mr. Baek reminds her that no one should visit their home. Mr. Baek shames her for having a nice time while their son lies in a coma. He says she's the reason their son is in a coma. Mrs. Baek says cooking for Eun Ha made her happy. Her husband declares her depression is back. Eun Ha follows the housekeeper into the Baek's closet but the housekeeper isn't there.
The housekeeper tends to the real Hee Sung.
Mr. Baek declares Hee Sung suffers every day but his wife is cooking for another. She retorts she cared for Hee Sung throughout his life when he was working all the time. She yells that her husband didn't answer her son's calls after hitting Hyun Soo. Mr. Baek declares he did his best. She scoffs that he only cares about himself. He hits his wife. He apologizes. She says this is who he is…a small provocation makes him reveal his true self. He opens the door to the room. Eun Ha is outside. He tells his wife to make sure Eun Ha says nothing. Mrs. Baek gets a grip and returns to Eun Ha.
Good scene.
Do Hae Sue cries looking at the pictures of Hyun Soo's family. He says his daughter is like her mother. His sister marvels at his changes. Hyun Soo says he only cared about himself. He admits selfishly he needs her help. He says their father had an accomplice. Hyun Soo says she met him once when the accomplice gave her the fish charm at their father's memorial. Hyun Soo says the fish charm belonged to the accomplice.
The brother and sister don't know Ji Won is eavesdropping. She realizes her husband isn't the accomplice because he's trying to find the accomplice. She hears Hyun Soo admits Mr. Park thought he was the accomplice but doesn't think that now. She assumes Hyun Soo made a deal with Mr. Park to keep quiet about his identity.
Do Hae Sue says the police questioned her too. She realizes the police woman that questioned her was Hyun Soo's wife. Hyun Soo confirms his wife is a police officer and investigating the case. He says he won't make any mistakes and will live as Hee Sung until the day he dies. Do Hae Sue asks if he loves his wife. Hyun Soo claims he doesn't love her. He says he doesn't feel love. Ji Won clinches her fists and takes the emotional hit. She walks away reeling.
She walks the streets and ponders everything. She tells herself she shouldn't be surprised. Her mother video calls with Eun Ha. Her daughter shows her a drawing. With tears in her eyes, Ji Won says she loves her daughter. Eun Ha echoes the sentiment.
Ji Won returns to the station. She leaves with Hyun Soo's bag that Mrs. Nam gave her. She burns the contents and destroys the evidence, including the Walkman. She murmurs she'll let her husband live as Hee Sung. She cries then walks away from the burning embers.
Hyun Soo walks home to find his wife waiting with a beer outside. He joins her. She reports their daughter is sleeping inside. He asks if she's okay. She claims to be stressed about a case. She says clinging to something that doesn't pan out is upsetting. She asks if she should quit. He doesn't like the stress she's under. He says she's a wonderful woman. She counters she's gullible too. Hyun Soo laughs. She notes they've lived there 5 years. She admits she's been happy. He suggests they have a party to celebrate 5 years there. She asks if he loves her. Hyun Soo takes her hand and kisses it. He says she need not ask about something that is obvious. Ji Won thinks he can live as Hee Sung with fake parents as long as their daughter's life is stable and secure. She informs her husband she'll be busy investigating the Yeonju murder case.
What's really bothering her is his claim that he doesn't love her. If he said he did, that would make his lie more palatable.
Flashback…Moo Jin's apartment…Do Hae Sue tries to recall her father's memorial service and the man that gave her the fish charm.
Flashback…memorial service….Do Hae Sue recalls a man that sobbed more than anyone else. He claimed her father helped him out of a jam once. He offers her the fish charm for luck. The man's voice was comforting. The man looked at her sleeping brother and said that Hyun Soo would have a terrible path to walk going forward.
Flashback…Moo Jin's apartment…Do Hae Sue tell Hyun Soo she gave him the fish charm because the man's voice was soothing. Hyun Soo says the man approached him on purpose. Do Hae Sue recalls the man wrote his phone number on her arm should she ever need him. Hyun Soo asks if she wrote the phone number down. She did but it went up in flames when she burned the house to destroy evidence that could be used against Hyun Soo. He plays the man's recording and tells his sister to listen to the background noise. She hears the tapping. She wonders if it from the workshop. Hyun Soo doesn't think so. MJ stares at Do Hae Sue and is lost in her beauty. He gets a grip and declares once they find the accomplice, their association will be over. Do Hae Sue agrees. Hyun Soo asks what Mr. Park told him.
The team moves into new offices. Ji Won unpacks her family items. Officer Im declares Ji Won has a great marriage and notes Detective Choi was wrong to say she shouldn't marry Hee Sung. Detective Choi chuckles that everyone makes mistakes. Team Lead Lee tells them to organize so they can get started. Ji Won takes off her wedding ring.
Moo Jin reviews what they know. He shares a new piece of information.
The team reviews the victims, locations, and statements. She believes one of the statements comes from the accomplice. Detective Choi notes she's sure of herself. Ji Won declares she will solve the case. She thinks once the case is solved, the next chapter of her life will begin.
Hyun Soo believes that his father and the accomplice knew Jung Mi Sook knew the wife would run away.
Flashback…Hyun Soo's father gives his son a bunny and tells him to take care of it any way he wants. His father says he'll watch his son.
Hyun Soo assumes his father set a trap for Jung Mi Sook, one that she fell into.
Flashback… Jung Mi Sook waits for the bus fish charm dangling from her phone. She gets a call about her husband.
The young victim is shown inside an employment agency. CEO Yeom Sang has a collection of flip cell phones. He offers the boy a drink while the gang members watch. The boy shows the flyer about working there. CEO Yeom suggests the boy write a resume.
Mr. Baek learns the reinvestigation of the Yeonju murders is underway. He activates a flip phone. He almost calls a contact but is interrupted by a message from the housekeeper that his wife is not well. He remembers their argument and leaves.
Do Hae Sue wishes she could remember the phone number or face of the accomplice. Moo Jin moons over her a bit. Hyun Soo notices. Moo Jin suggests pizza. Hyun Soo tells him this isn't fun and games. He says Moo Jin won't get his sister back. He reminds him what Moo Jin said to Do Hae Sue all those years ago. Hyun Soo reminds his sister how Moo Jin's words made her cry. Hyun Soo tells them to focus on finding the accomplice. They listen to the recording again. Moo Jin points out he's the feeling human while Hyun Soo feels nothing. He advises Hyun Soo not to show his wife his true self. Do Hae Sue objects. Moo Jin snaps she shouldn't defend him. Hyun Soo calls him useless and starts to leave. Do Hae Sue tells him to sit. Hyun Soo complies. She tells her brother to say what he wants. Hyun Soo says he's said what he wants to. Do Hae Sue encourages him to tap into his feelings. She says he's different. He wants a life and a family. Hyun Soo is taken aback.
Nice!
Detective Choi declares finding Hyun Soo is the key not going through old files. He points out that Hyun Soo must have seen the accomplice when Jung Mi Sook was brought to his father's house. Officer Im wonders how to find Hyun Soo. Ji Won declares she needs to go to the bank. Ji Won strides down the hall. She decides she must let Hyun Soo know he met the accomplice too.
Mrs. Baek stares at her sleeping son.
Flashback…Hee Sung teases his mother that he wants to be feed. She feeds him. He feeds her.
Mrs. Baek cries. She smooths her son's hair.
Hyun Soo declares he'll live as Hee Sung, that's all he wants. He doesn't want to lose the life he has, that's all that matters. That's all he feels. He doesn't want to upset Moo Jin but sometimes he doesn't understand why people interact like they do. Hyun Soo says he'll says whatever Moo Jin needs to secure his help. Moo Jin chides him that there is a better way. He says he'll go drinking with Officer Im. Do Hae Sue thanks Moo Jin for accepting her brother's words. Ji Won calls Moo Jin. He puts it on speaker after telling them to be quiet. Moo Jin pretends to be sick when she asks to meet him. The door bell rings. Moo Jin goes to the door believing it is pizza. He opens the door and is shocked to find Ji Won smiling at him. Moo Jin speaks loudly so Do Hae Sue and Hyun Soo can hear that Ji Won is there. She claims to be curious about what Moo Jin is working on. Moo Jin claims not to feel well. But the pizza delivery guy arrives with 3 pizzas. Ji Won spies the multiple pair of shoes in the entryway. She asks if he has guests. Hyun Soo clutches his chest.
Mrs. Baek thanks her son for lasting as long as he could. She tells him the suffering will end for both of them. She tells her son to go first and she'll follow soon. She removes the breathing device from his face. The monitors start beeping. She backs away and watches her son gasp for breath. Mr. Baek enters and struggles with her. She declares their son must be allowed to die. She says he can still live the life he wants.
Hyun Soo clutches his heart and gasps. Ji Won asks if Moo Jin has guests. Moo Jin tries to get rid of her. Hyun Soo calls to Moo Jin. Ji Won's eyes widen in surprise.
The Baek's struggle. Mr. Baek and Mrs. Baek stare at their son in shock. He's eyes are open and he's breathing.
Hyun Soo walks to the front door and stares at his wife.
The Baeks stare at their son who is breathing on his own.