It's creepy how Chef Kwon revealed his real expression after realizing Doctor Chun learned he is the barcode killer. Finally, there's no more hiding from the viewers. Chef Kwon is the psychopath serial killer.
Accidentally Doctor Chun had uncovered Chef Kwon's secret. He was returning the box he kept for Chef Kwon while being detained in the police station. A moving company got the box and delivered it to Chef Kwon's place. He received the box. But before he was able to leave it he was tempted to open the box, even wounding his finger, a little blood spilled. There were books inside and he realized they were diaries of Joo Ma Ri. There was really nothing to be suspicious about but then as he flipped through the pages, the last page came and there he saw a photo of an arm with slits like a barcode and below was Joo Ma Ri's name.
Doctor Chun heard footsteps and had enough time to close the box before Chef Kwon appeared around the corner. His wounded finger did not escaped the Chef's eyes. He tried to detain the doctor but apparently the doctor had to go. He was leaving the next day. He was also meeting Moo Gak that night at a church. The call came when Doctor Chun was at the restaurant with Chef Kwon so yes, the latter heard about it.
Inside the house, Chef Kwon opened the box and saw there was blood stains on the photo at the back page of the diary. Clearly, the doctor had seen the photo. His secret has now been revealed. At that time, doctor Chun was in a hurry driving away, anxious and nervous and scared of what he learned about the Chef. Prior to his going to Chef Kwon's place, he already realized that there were 2 Choi Eun Seol three years ago in the same hospital in Jeju. One was Moo Gak's sister that died and seemed that Moo Gak was blaming him as the killer. The other Eun Seol was the daughter of the couple who were murdered. He knew about Eun Seol aka Cho Rim back then because at that time his wife was also very sick and needed a donor for organ transplant. As a husband he wanted his wife to live longer and receive transplant but there was no donor yet. He found out about Eun Seol who barely escaped a killer and that she was the only survivor. It was a selfish plan for him knowing Eun Seol can die any moment or not wake up from coma. He planned on injecting her something that will make her die soon but at the last moment he stopped himself.
Later when he met Cho Rim, he was glad that she is fine and doing okay. He followed her one time
[that's when I thought he was stalking her like a killer] and saw that she is living a cheerful life. He wanted to tell her his story but he decided not to bother her now when she seems not to have any recall about her past, living as Cho Rim now. Still, he wrote a letter to her. The letter was not intended for her to read but somehow the fate of the letter I think will be revealed later. He put the letter on his table. His assistant came in with books that will be returned to another doctor and when the woman picked the books again the letter happened to be transfered with the books inside a box. So, now the letter will be sent to the owner of the books. He also realized that she is the living witness to the murder.
That night Doctor Chun went to the church where he was supposed to meet Moo Gak. Unfortunately, Chef Kwon arrived before Moo Gak. The doctor tried hard to act normal despite his fear. Chef Kwon sat beside him. Doctor Jung waited for the right moment to flee but too late, Chef Kwon was too fast for him.
Moo Gak arrived at the church but there was no trace of Doctor Chun. The following day, the doctor was missing. He thought the doctor flee. He called his superior and asked to put a ban on Jung traveling abroad. The doctor can not be traced. Every thing now seems to be pointing towards Doctor Chun as the killer.
It's frightening how Chef Kwon prepared food inside his house. And there were two servings as if there is another person inside that house. At the police department, Moo Gak is discussing about his theory on the barcodes. His analysis seems to be exact. The series of numbers being used are like numbers found in barcodes on books. Each barcode signifies a corresponding book or in this case victim. The numbers in the last part are in chronological order. Moo Gak supposed that if there is a sixth victim, then the barcode for that victim will end in 06.
Creepy but that was the number that incidentally matches Doctor Jung's. A barcode was attached on a book with the doctor's name on it. Then Chef Kwon put the book in a shelf with the other books with barcodes. Presumably, they were his victims' books lined up on that shelf.
What's the catch? Still, the serial killer leaves me intrigue on how and why he killed them.
For the romance part, Cho Rim's delusion had me getting excited. I thought Moo Gak really hugged her in the opening of the episode only to find out she was dreaming. Moo Gak was sound asleep with his head on her lap. She had to wake him up. Like a fool, she realized she was imagining the whole scenario in her head only.