In the gripping ninth episode of Doubt's inaugural season, the narrative reaches a fever pitch as the noose tightens around Ha-Bin's neck, and Tae-Soo's desperation to prove her innocence intensifies. The episode opens with Tae-Soo's interview with Jun-Tae, which is abruptly interrupted by the captain, who pulls him off the case. Despite this setback, Tae-Soo pleads for a chance to remain on the investigation, firmly asserting Ha-Bin's innocence. The captain and chief are skeptical, given the personal nature of the case, but a twist occurs when Jun-Tae insists on speaking only with Tae-Soo, forcing the captain to reconsider his position.
The episode takes a dramatic turn when Tae-Soo is sent home to bring Ha-Bin in for questioning. Upon arriving, he discovers that the evidence bag, crucial to Ha-Bin's defense, is missing, with Ha-Bin claiming to have destroyed it. This revelation seems to leave no avenue for proving her innocence, yet Ha-Bin remains unafraid, confidently telling her father that the key to her exoneration lies in uncovering the true perpetrator.
In a pivotal scene, Tae-Soo seeks an audience with Seung-Hui's son, Do-Yoon, who admits to seeing Min-A on the day of her death—a fact that directly contradicts Seung-Hui's previous statements. Armed with this new information, Tae-Soo returns to the station, despite the captain's disapproval, as he is officially off the case. Ha-Bin, when questioned, is unreserved in her responses, even admitting to previous lies, in a bold move that could either exonerate or incriminate her.
Meanwhile, the episode presents a chilling scene where Eo-Jin visits Seung-Hui, only to be met with hostility from Do-Yoon, who, in a fit of rage, pushes her down the stairs. This incident, while not causing serious harm, sheds light on Do-Yoon's unstable nature and hints at a deeper dysfunction within the family dynamic.
As the investigation progresses, Seung-Hui and Do-Yoon are taken into custody, while Ha-Bin is released. Dae-Hong, seeking to protect the young boy, takes it upon himself to question Do-Yoon. Through a series of simple yet probing questions, Dae-Hong uncovers the truth: Do-Yoon had found pills in the basement, which Choi had claimed would make anyone happy. In a misguided attempt to please Min-A, he gave them to her, believing it would make her happy. However, this revelation is not the full story, as Dae-Hong suspects that Min-A's death was not a result of the pills but a cover-up for an accidental death.
In a significant plot development, Eun-Jin arrives at the station with videos captured on her iPad, showing Ha-Bin's mother burying Su-Hyeon's body. This evidence, coupled with the revelation that Young-Min had blackmailed Ha-Bin's mother, leading to her suicide, begins to unravel the tangled web of deceit. Seung-Hui, in an attempt to prove her innocence, brings forth the cash that Young-Min had hidden, which is believed to exonerate her from the crimes.
The episode culminates in a shocking confession: Seung-Hui admits to killing Min-A by poisoning her, whether it was through the pills or another substance remains unclear. The parallels drawn between Tae-Soo and Ha-Bin, and Seung-Hui and Do-Yoon, are striking. While Seung-Hui is willing to go to any lengths to protect her child, Tae-Soo's righteousness is put to the test. Min-A had discovered that Choi had threatened Ha-Bin's mother and, seeking a share of the money, had approached Seung-Hui, leading to her untimely death.
As the final episode looms, the question of who killed Su-Hyeon remains unanswered. The possibility that Tae-Soo himself could be implicated adds a layer of intrigue to the already complex narrative. The ninth episode of Doubt leaves viewers with more questions than answers, setting the stage for a climactic conclusion that promises to reveal the truth behind the murders and the intricate web of lies that have enveloped the characters.