Yeonghan is on the verge of falling from a height, but Gyeong-hwan is there to support him and manages to grab hold of the rope just in time. Hee-sung notices the activities outside the window and attempts to apply more force, but Yeonghan manages to break through the window and stop Hee-sung just in time. He proceeds to apprehend him for trying to commit murder and for the killing of Soonjung.
Meanwhile, Commander Baek makes an agreement with Hee-sung’s father, Jung Byung-pil, using Hee-sung’s crime as a bargaining chip. He entices him with the promise of assistance in importing Pachinko machines into the country. Byung-pil is unable to say no to Commander Baek and agrees to his terms. In the meantime, Commander Baek is feeling content but his mood quickly changes when he receives the information that Unit 1 has apprehended Hee-sung.
He hurries to assist Hee-sung, but the team intervenes, warning him that Hee-sung was caught in the act and aiding him would only cause problems for Commander Baek. Yeonghan then cautions Commander Baek that he will not have much time left before they come after him as their next victim. Byung-pil hears about this and attempts to reach out to Commander Baek to get more information, but Commander Baek is preoccupied with trying to keep himself alive.
At the same time, Yeonghan and Sang-sun seek out Nam Jung-gil to obtain his testimony as evidence to incriminate Hee-sung. After much persuasion, Yeonghan manages to convince Jung-gil to confess that it was Hee-sung who originally came up with the plan to involve girls from the factory and paid them to keep quiet. Nevertheless, Soon Jung met her demise when the opium they gave her failed to have its intended effect on her and she resisted.
But Jung pil is unable to testify in court because he is afraid of Hee-sung’s father. Yeonghan is starting over from scratch because without Jung-gil’s testimony, it will be difficult to keep Hee-sung in custody. At that moment, Namsin shows up and announces that she has successfully persuaded the individuals who were harmed by the group to join them for a meeting.
Yeonghan quickly goes to find the girls, tells them about the person who has passed away, and asks them to give a statement in court. Nonetheless, the victims are hesitant as they desire to erase the terrible memories that were imposed on them by the men. Yeonghan is unable to persuade them and has to respect their decision. At that moment, Hye-ju gives the victims a letter from the deceased mother, which is meant to bring hope for their future.
This causes them to collapse emotionally, ultimately leading them to testify in court. One of them informs Yeonghan that when she attempted to report the incident at a police station, Commander Baek cautioned her to avoid going to the police station if she valued her life. Somewhere else, Commander Baek makes the decision to escape as soon as he can and asks Byung-pil for 10 million hwan in exchange for delivering Jung-pil to him.
Byung-pil agrees to his request but instructs his men to eliminate Commander Baek when he arrives for the exchange. At the hospital, Inspector Nam discovers that Jung-pil is missing. He quickly notifies Chief Yu about the situation and then hurries to follow the suspect. Chief Yu promptly contacts the bookstore to notify Yeonghan , and together they wait for more updates from Officer Nam.
Shortly after, Officer Nam contacts Chief Yu to inform him that the suspect has reached the Jeongham Cathedral, and the teams promptly head to the cathedral. Officer Nam is on the verge of going into the cathedral, but he pauses upon noticing a group of men entering instead. The men happen to be Byung pil’s men and they encircle Commander Baek and his partner in crime detective Kang, attempting to defeat them. However, Commander Baek is not easily defeated and puts up a tough fight, killing some of them. Upon Yeonghan’s arrival at the cathedral, chaos ensues and he is startled to hear the sound of a gunshot.
Chief Yu, along with Soo-man and Ji-seob from Unit 2, also arrives. Yeonghan instructs them to focus on rescuing the lives of the civilians as a top priority. The team enters while Commander Baek is engaged in a fight with Byung-pil’s men. They attempt to intervene in the ongoing gunfight and Commander Baek seizes the opportunity to grab a civilian and flee from the scene.
The police team evacuate the civilians while apprehending Byung-pil’s men, as Yeonghan quickly follows Commander Baek. Sang-sun, Ho-jeong, and Kyeong-hwan quickly move to assist in apprehending Commander Baek and his partner. But Commander Baek has kidnapped a pregnant woman, bringing back memories of the past for Yeonghan . He instructs Yeonghan to toss his gun and then kick it in his direction. Yeonghan sees Ho-jeong nearby and follows Commander Baek ‘s instructions while contemplating his next move. This results in an opportunity for the two of them to rescue the woman, but unfortunately, Commander Baek accidentally shoots Yeonghan in the shoulder. Following their altercation, Yeonghan ensured his victory in the fight by successfully placing handcuffs on Commander Baek ‘s wrists.
In a different location, Sang-sun is attempting to prevent Detective Kang, Commander Baek’s accomplice from taking Jung-pil away, but it is only with the assistance of Gyeong-hwan that he is ultimately able to stop him. The men have been captured at last and sent to prison, where Hee-sung and Commander Baek are given severe punishments in the final verdict. Cheers erupts in Jeongnam Police Station, signaling the return of justice for which they had all tirelessly fought.
Nevertheless, Yeonghan is still discontented because Byung-pil was able to avoid being punished. Nevertheless, Hye-ju helps him see that he has improved the world for his children, which is the most important thing, and there is no reason to feel sorrowful about it. Yeonghan is re-energized by this and passes on the same message to his team with renewed enthusiasm.
Soon, Yeonghan encounters former prisoners who have reformed and assists them in starting afresh. Afterwards, he learns that Chief Yu was promoted to the new position of Superintendent, giving the police station another cause for celebration. Chief Yu selects Yeonghan as the new leader of Unit 1, marking the beginning of Chief Park and his team’s quest.
In the present, Yeonghan reconnects with the ex-convicts he had previously assisted in rebuilding their lives. The men express their gratitude to Yeonghan for his contributions and reflect on the time they spent with the Unit 1 team. The men get together, reminiscing about their friends who have passed away, sharing drinks, food, and memories.
The following day, Yeonghan pays a visit to his former teammates at the cemetery. He reminisces about how much he misses them and mentions that their children have also been coming to see him. He remains seated and eventually falls asleep until evening, when he wakes up, greets them, and departs.
The prequel series of the show has concluded, leaving a lasting impact on the audience as we reflect on the incredible journey of Chief Detective over the past year. The fantastic cast of actors, emotional moments, and captivating plot have made this prequel a memorable and moving experience. The cast of actors portrayed their characters so brilliantly that the audience felt a sentimental connection to them, particularly in the emotional final scene where Yeonghan bids them farewell at the grave. The seamless flow of events and the amazing stage set-up transported the audience back in time, making each arrangement flawless and engaging. The passage of time was well depicted, leaving the audience eager for more.
Overall, the prequel series managed to create a memorable experience for the audience, leaving us with a desire to explore the original 1971 show and reflect on the journey of Chief Detective.
Rating for the show 8.5/10