The episode begins with a flashback to 2000, where a young girl named Lee Jae-kyung is seen playing in a park. She is suddenly approached by a man who lures her away with a promise of a puppy. The scene shifts to the present day, where Detective Park Hae-young receives a call from the past through the mysterious walkie-talkie that connects him to Detective Lee Jae-han, who is in the year 2000. Hae-young learns that Jae-kyung has gone missing and that the case is linked to a series of child abductions.

Hae-young and his partner, Detective Kim Hye-soo, begin to investigate the case, retracing Jae-kyung's last known movements. They interview her parents, who are distraught and desperate for answers. Hae-young feels a deep sense of urgency, knowing that they must act quickly to find the girl before it's too late. Meanwhile, Jae-han, in the past, is also working on the case, trying to gather clues and piece together the timeline of events leading to Jae-kyung's disappearance.

As the investigation unfolds, Hae-young and Hye-soo discover that there are inconsistencies in the statements given by witnesses. They suspect that someone is manipulating the information surrounding the case. Hae-young's determination grows as he realizes that the key to solving the case lies in uncovering the truth behind these manipulations. He feels a personal connection to Jae-kyung, driven by the urgency to save her and prevent her from becoming another victim.

In a pivotal moment, Hae-young receives another call from Jae-han, who has uncovered a lead about a suspicious man seen near the park on the day of Jae-kyung's abduction. Jae-han describes the man's appearance and urges Hae-young to follow up on this lead. Hae-young and Hye-soo rush to the location where the man was last seen, hoping to find him before he disappears again.

The detectives manage to track down the suspect, who is revealed to be a local handyman with a history of troubling behavior. They confront him, and during the interrogation, he becomes increasingly agitated. Hae-young presses him for information, and the tension escalates as the handyman begins to crack under pressure. He eventually admits to having seen Jae-kyung but insists he had nothing to do with her disappearance. Hae-young, however, senses that he is hiding something crucial.

As the investigation continues, Hae-young and Hye-soo discover that the handyman had been in contact with a known criminal involved in child trafficking. They realize that the case is much larger than they initially thought, and they must act quickly to prevent further abductions. Hae-young feels the weight of responsibility on his shoulders, knowing that time is running out for Jae-kyung.

In a dramatic turn of events, Hae-young receives another call from Jae-han, who has made a breakthrough in the case. Jae-han reveals that he has found a hidden location where the trafficker is believed to be holding Jae-kyung. Hae-young and Hye-soo prepare to raid the location, filled with a mix of hope and dread. They gather a team of officers and head to the site, ready to confront the trafficker and rescue the girl.

The raid unfolds with high tension as the team moves in. They breach the door and find themselves in a dimly lit room filled with disturbing evidence of the trafficker's activities. Hae-young leads the charge, determined to find Jae-kyung. They search the premises, and after a tense moment, they discover her locked in a small room, frightened but alive. Hae-young rushes to her side, feeling a surge of relief wash over him as he reassures her that she is safe now.

As they escort Jae-kyung out, the trafficker appears, leading to a confrontation. A struggle ensues, and Hae-young and the officers engage in a physical fight with the trafficker. Hae-young's adrenaline spikes as he fights to protect Jae-kyung, driven by the need to ensure her safety. After a tense struggle, they manage to subdue the trafficker, and he is taken into custody.

The episode concludes with Hae-young reflecting on the case and the emotional toll it has taken on him. He feels a sense of accomplishment in having saved Jae-kyung but is also haunted by the knowledge of the many other victims who may still be out there. The connection between Hae-young and Jae-han deepens as they continue to work together across time, united in their mission to bring justice to those who have suffered.

In the ending of "Signal," season 1, episode 12, titled "The Case Was Manipulated," the characters face the consequences of their actions as they unravel the truth behind a manipulated case. The episode concludes with a sense of resolution for some characters while leaving others with lingering questions and unresolved emotions.

As the episode unfolds, we see Detective Park Hae-young and his team working tirelessly to uncover the truth behind a series of murders that have been linked to a larger conspiracy. They discover that the case they have been investigating was manipulated by a powerful figure, leading to a shocking revelation about the true nature of justice and the lengths people will go to protect their interests.

In the final scenes, Hae-young confronts the antagonist, leading to a tense standoff that tests his resolve and commitment to justice. The emotional weight of the case takes a toll on him, as he grapples with the implications of the truth and the impact it has on his relationships with his colleagues and loved ones.

The episode ends with a bittersweet resolution, as Hae-young and his partner, Detective Ji An, reflect on their journey and the sacrifices they have made. While they have achieved a measure of justice, the emotional scars remain, and the future is uncertain.

As the episode begins, the tension is palpable in the air as Detective Park Hae-young and his team gather in the precinct, poring over evidence from the manipulated case. The atmosphere is thick with urgency; they know that time is running out to uncover the truth. Hae-young, driven by a deep sense of justice and a personal connection to the victims, is determined to expose the corruption that has tainted the investigation.

Scene transitions to Hae-young and his partner, Detective Ji An, as they sift through old case files and witness statements. Ji An, who has been a steadfast ally, shares Hae-young's frustration and determination. The two detectives share a moment of vulnerability, revealing their fears and hopes for the future. Their bond strengthens as they navigate the complexities of the case together.

As they delve deeper, they uncover a web of deceit that leads them to a powerful figure who has been manipulating events from the shadows. The revelation hits Hae-young hard; he realizes that the justice system he has always believed in is flawed. This realization fuels his resolve, but it also weighs heavily on his conscience.

In a pivotal scene, Hae-young confronts the antagonist in a tense showdown. The confrontation is charged with emotion, as Hae-young's anger and frustration boil over. He demands answers, seeking to understand how someone could exploit the system for personal gain. The antagonist, calm and collected, tries to justify their actions, but Hae-young is unwavering. The stakes are high, and the outcome of this confrontation will determine not only the fate of the case but also Hae-young's own moral compass.

As the confrontation escalates, Ji An arrives just in time to support Hae-young. Together, they confront the antagonist, showcasing their unwavering commitment to justice. The scene is intense, filled with raw emotion as they fight not just for the victims but for their own beliefs and integrity.

In the aftermath of the confrontation, the team gathers to discuss the implications of their findings. They realize that while they have exposed the truth, the scars of the case will linger. Hae-young reflects on the emotional toll it has taken on him and his colleagues. The weight of their experiences hangs heavy in the air, a reminder of the sacrifices they have made in pursuit of justice.

The episode concludes with Hae-young and Ji An standing together, looking out over the city. They share a moment of quiet reflection, acknowledging the challenges they have faced and the uncertain future ahead. While they have achieved a measure of justice, the emotional scars remain, and the journey is far from over. The fate of each character is intertwined with the unresolved questions of morality, justice, and the human experience, leaving viewers with a poignant sense of closure yet an awareness of the complexities of life.

In "Signal," season 1, episode 12, titled "The Case Was Manipulated," there is no post-credit scene. The episode concludes without any additional scenes after the credits roll. The focus remains on the resolution of the main storyline and the emotional arcs of the characters involved, particularly the impact of their actions and the lingering consequences of the cases they have worked on together. The episode wraps up the narrative threads established throughout the series, emphasizing the themes of time, justice, and the personal sacrifices made by the characters.

Throughout the episode, Park Hae-young grapples with his feelings of frustration and determination as he seeks to uncover the truth behind the manipulated case. His relationship with Lee Jae-han is tested as they confront the implications of their findings, leading to moments of tension but also a reaffirmation of their bond as they work together.

In this episode, the manipulation of evidence becomes a central theme as the characters uncover that crucial pieces of information have been altered to mislead the investigation. This revelation leads to a deeper exploration of trust and betrayal among the team.

The episode reveals that key witness statements and forensic evidence have been altered, which misdirects the investigation. This tampering creates a sense of urgency for the characters as they race against time to piece together the truth, highlighting the emotional stakes involved.

Cha Soo-hyun plays a pivotal role in connecting the dots between the manipulated evidence and the true events of the case. Her investigative skills and emotional resilience shine through as she confronts her own doubts and fears, ultimately leading to critical breakthroughs.

Park Hae-young experiences a tumultuous emotional journey as he confronts the reality of the manipulated case. He feels a mix of anger, betrayal, and determination, which drives him to push through the obstacles in his path, reflecting his deep commitment to justice and the victims involved.

In "Signal" Season 1, Episode 12, titled "The Case Was Manipulated," there are several elements that may be considered objectionable or upsetting for children or sensitive viewers:

1. Violence: The episode contains scenes depicting crime and violence, including discussions of murder and the aftermath of violent incidents, which may be distressing.

2. Emotional Trauma: Characters experience significant emotional turmoil, including grief and despair over past events, which could be heavy for younger audiences.

3. Themes of Manipulation and Deception: The plot revolves around manipulation of evidence and the justice system, which may be complex and unsettling for younger viewers to understand.

4. Intense Situations: There are moments of high tension and suspense that could be frightening, particularly for those sensitive to thrillers or crime dramas.

5. Mature Themes: The episode explores themes of justice, morality, and the impact of crime on families, which may be too mature for younger audiences.

These elements contribute to a darker tone that may not be suitable for all viewers, particularly children.