As Episode 13 unfolds, we are taken back in time to the year 2009. In this flashback, we witness Woo-jae behind the wheel of his father’s car, on his way to pick up Na-ri from the factory. However, tragedy strikes as he accidentally collides with her while she is running on the road. In a panic, Woo-jae immediately calls for emergency assistance and then makes the split-second decision to transport Na-ri himself. Despite the gravity of the situation, Woo-jae musters up the courage to inform his father about the accident. Upon hearing the news of Na-ri’s untimely passing, his father advises him to return home rather than accompany her to the hospital.
Currently, Woo-jae visits his father at his house and confides in him about Eun-sae. In a flashback, we see Eun-sae calling Woo-jae and blackmailing him with the threat of revealing something he said while sleeping, which Woo-jae suspects is related to him confessing to killing Na-ri. Back in the present, father and son deliberate on how to handle the situation. Despite his initial reluctance, Woo-jae ultimately decides to conceal the truth, now motivated by the desire to protect his child.
Tae-heon and Secretary Gong sit down for a meal together, during which Gong offers Tae-heon some advice – he suggests that it may be best for both Tae-heon and Jung-won if Tae-heon were to let go of his feelings for her. Meanwhile, Jung-won makes a visit to her late father’s grave, where she confides in him about her dilemma regarding Woo-jae and the possibility that he may be a murderer. She expresses her determination to uncover the truth, not only for her own sake but also for the well-being of her child.
After visiting a spot in Mueon previously visited by Woo-jae, Ae-na discovers it is actually the site of the Bongto fire memorial. She contacts Jung-won to inform her that news of her pregnancy has been leaked by Woo-jae’s father. Ae-na then confronts Woo-jae over the phone, expressing her determination to not be swayed by any amount of media coverage and refusing to return to live with him. Additionally, she discovers that Woo-jae is currently in Mueon for the grand opening of the new Mujin resort.
Following a discussion with his father, Woo-jae advises him against approaching Jung-won. Pan-ho then departs to rendezvous with Assemblyman Mo, while Jung-won observes their interaction from a distance. During their meal together, Mo attempts to negotiate for a higher share of profits in relation to the resort project.
When Pan-ho uses his understanding of Woo-jae’s emergency call to shift the blame onto a driver and warns Mo that he will uncover the truth about the scar on his solar plexus, Mo retaliates by revealing that he possesses a fragment of Pan-ho’s car’s headlight stained with blood. This revelation puts Pan-ho in a difficult situation as he is now faced with the consequences of his actions.
After listening to the 911 recording, Tae-heon and his team are able to confirm that it was indeed Woo-jae on the call. They come to the realization that locating Na-ri’s body is now their top priority. Meanwhile, in Mueon, Jung-won tails Woo-jae to a hotel room and eventually watches as he exits the room later on.
In another location, Lee Ba-reun is using a shovel to dig into the earth within a dense forest. With him is a white pinwheel, a memento he acquired at the Bongto memorial event. During his time there, he had also encountered Woo-jae and decided to trail him into the wilderness. There, he observed Woo-jae kneeling on the ground, pouring banana milk into the soil – a gesture that held significance for Na-ri.
Currently, Ba-reun stumbles upon a skeleton in the same area. However, he is not alone as someone suddenly grabs him and begins choking him until he loses consciousness. Just as the assailant is about to bury Ba-reun, two security guards appear and intervene, causing the attacker to flee. Meanwhile, Tae-heon receives a phone call.
Upon arriving in Mueon, Tae-heon is filled with a sense of dread as he immediately recognizes the lifeless body of Ba-reun. Jung-won, who happens to be in the vicinity, notices Tae-heon’s distress and approaches the group of police officers surrounding the body. With a heavy heart, Tae-heon musters the courage to inform Jung-won about the tragic fate that has befallen Lee Ba-reun. As she lays eyes on the lifeless form of her dear friend, memories of their shared experiences flood her mind, overwhelming her with grief as tears stream down her face.
After some time, Tae-heon comes to the realization that Woo-jae is also residing in Mueon. This discovery is coupled with the confirmation that the skeleton found is indeed Lee Na-ri, a fact that Tae-heon promptly shares with Jung-won. Being the determined journalist that she is, Jung-won decides to approach Woo-jae directly to address the situation. She investigates further by reviewing security footage and consulting with a security guard, who informs her that Woo-jae only visited the hotel bar and did not leave the premises.
As Jung-won and Woo-jae sit in his room, she shares with him the video footage of the man who killed Eun-sae, revealing that this same man was responsible for her father’s murder. Shocked and confused, Woo-jae denies any involvement and proves his innocence by calling a hospital director to confirm that he was in a psychiatric ward at the time of the murder. Jung-won is overcome with relief upon learning that Woo-jae was not the perpetrator. Meanwhile, Pan-ho, from his hotel room, notices something suspicious through his window.
The following day, Woo-jae decides to accompany Jung-won to the location where Na-ri died, as he is curious to see it for himself. Tae-heon grants permission for them to visit the forest where the tragic incident took place. Upon arriving, they inquire at a nearby store for any security footage that may have captured the events leading up to Na-ri’s death, only to discover that the recordings have been erased. Undeterred, they proceed to the actual spot where the murder occurred. Tae-heon then questions Woo-jae about his encounter with Na-ri on Christmas Eve in 2009, to which Woo-jae confirms that they had met before she left for the factory.
As Jung-won continued her stroll through the forest, she started to feel unwell. Taking a brief break in the restroom, Tae-heon seized the opportunity to share the 911 call recording with Woo-jae. In the call, Woo-jae admits that his driver was behind the wheel during the accident involving Kim Min-chul. He also suggests that Tae-heon verify the information with Min-chul himself. To everyone’s surprise, Tae-heon discloses that he had already obtained the security footage from the nearby shop the previous night.
On the day of the Bongto memorial, Tae-heon spotted a mysterious figure clad in black making their way towards the forest. Despite his protestations, Woo-jae was unable to convince Tae-heon that he was not the culprit. Determined to get to the bottom of the situation, Tae-heon vowed to apprehend the man in black. As they prepared to go their separate ways, Jung-won revealed to Tae-heon a crucial piece of evidence that Yoon-young had left behind – a video that shed light on her father’s involvement in the mysterious events unfolding in their town.
In a flashback to 2008, a scene unfolds where a student is seen attempting to remove an item from a man’s pocket. The object in question is revealed to be a knife adorned with a unique spiral pattern. The man is later identified as Secretary Gong. As the flashback comes to a close, a car pulls up alongside them, prompting Gong to exit the vehicle, leaving the outcome of the situation unknown.