In Miss Night and Day, it is revealed that Gong Eun-sim, played by Bae Hae-Sun, stole Na Ok-hui’s identity to work at the District Prosecutors’ Office.
Director Baek decides to trust Mi-jin and help her find the person who murdered his wife as well as her aunt by providing her with records on fentanyl distribution in Seohan.
The records go back twenty-four years. One name, Gong Eun-sim, stands out among the rest due to her purchases coinciding with disappearances and murders in the city.
This woman purchased fentanyl when several women in the city disappeared around twenty years ago and then purchased it again recently under an alias.
Gong Eun-sim’s involvement in the disappearances
Twenty years ago, Gong Eun-sim took night classes at nursing school and provided beauty injections or sedatives on a house-call basis.
She was called to administer an injection to Director Baek’s wife, Kang Gyeong-hui, at a motel. Gong Eun-sim injected her with a sedative and stole all her valuables.
However, Kang Gyeong-hui woke up, which led to Gong Eun-sim murdering her. She also stole Kang Gyeong-hui’s bank book and attempted to withdraw money from her account.
Mi-jin’s aunt, a bank employee who was asked by Director Baek to inform him if his missing wife tried to withdraw money, became suspicious when Gong Eun-sim came to the bank.
She tried to call Director Baek but could not reach him. That night, Gong Eun-sim killed Mi-jin’s aunt after realizing that she had grown suspicious.
This murder was witnessed by Ji-ung’s mother. When Ji-ung’s mother decided to tell the police about what she had witnessed, Gong Eun-sim killed her as well.
Gong Eun-sim got away with all these murders, as most of the victims’ bodies were never found and they were assumed to have run away.
The revelations of Gong Eun-sim’s crimes
Twenty years after the disappearances, Gong Eun-sim now owns a teahouse. She closes her teahouse to work at the District Prosecutors’ Office.
To become a senior public intern there, she kills a woman named Na Ok-hui, who was selected for the job, and assumes her identity.
Another senior intern, Ko Na-heun, witnesses the murder. As a result, he is also killed by Gong Eun-sim, who is never suspected by anyone.
However, Gong Eun-sim stops coming to work after Director Baek is arrested, fearing that his testimony might reveal her crimes.
At the same time, Mi-jin finds out that the woman she knows as Na Ok-hui lied about her identity and asks Byung-duk to run a background check on her.
The check reveals that Na Ok-hui is, in fact, Gong Eun-sim, the person they are searching for. With Director Baek’s help, Mi-jin also finds out that she smelled poppy on Ko Na-heun’s murderer.
Mi-jin breaks into Gong Eun-sim’s locker at work and finds a poppy flower in it, which confirms that she is the one who murdered Ko Na-heun and is now targeting her.
Before Mi-jin can do anything about it, Gong Eun-sim kidnaps Mi-jin’s father, who comes to her for help, and threatens Mi-jin.
Gong Eun-sim used to work at a coffee shop twenty years ago. Mi-jin’s father had met her to question her about one of her coworkers who had gone missing.
She led Mi-jin’s father to believe that she could help him find his wife’s sister, which is why Mi-jin’s father seeks her out once again twenty years later.
Mi-jin is left with no choice but to meet Gong Eun-sim alone to save her father. Gong Eun-sim now plans to kill Mi-jin, who has encountered Ko Na-heun’s murderer and can testify against her.
Also Read: Baek Cheol-gyu: Miss Night and Day character explained
