In the fifth episode of Seoul Busters, titled "Denial," the team delves deeper into the mysterious fire case that has left Hyo-joo in a coma and suffering from amnesia. The episode begins with a twist as one of Hyo-joo's friends informs the detectives about her stalker ex-boyfriend, Jung-hyun, who might have been following her on the night of the incident. This revelation adds a new layer of complexity to the investigation, as the team starts to consider the possibility of a stalker turned arsonist.

Yu-bin, the team's new captain, revisits the crime scene, his mind racing with questions. His intuition tells him that there's more to the case than meets the eye, but the pieces just don't seem to fit. His relentless pursuit of the truth leads him to reenact the crime in his mind, searching for the missing link that will unravel the mystery.
As the team gathers for a briefing, the list of suspects grows. Jung-hyun, with his history of stalking, tops the list. Sang-ju, the neighboring chicken restaurant owner, is a close second, given his past conflicts with Mr. Yoon and his potential motive for arson. The landlord, who could profit from the insurance payout, and Mr. Yoon himself, who might have had a reason to stage the fire, are also considered. The briefing room is tense as each suspect is discussed, and the team is tasked with bringing them in for questioning.
A moment of levity occurs when Jung-hyun, the team's resident tech expert, is distracted by a T-Rex figurine, leading to a comedic scene that lightens the mood. Despite the humor, the team's mission is clear: they must interrogate the suspects and find the truth.
Yu-bin and Min-seo visit Mr. Yoon, where they discover that Hyo-joo's mother is bedridden with depression, adding another layer of tragedy to the case. Mr. Yoon's reaction to the arson theory is one of surprise, and his hope for Hyo-joo's recovery is palpable. Yu-bin remains unmoved, however, sticking to the facts and refraining from commenting on Mr. Yoon's character.
The forensic report suggests that a flammable liquid was used to start the fire, pointing towards a deliberate act. Joong-ryeok, the team's muscle and heart, listens to Hyo-joo's distressing call to the police, her fear of her ex-boyfriend evident in her voice. This leads him to track down Jung-hyun, resulting in a confrontation that tests Joong-ryeok's patience and morality.
Back at the station, chaos ensues as all the suspects arrive at once, thanks to a mix-up by Tan-sik. The team is forced to split up and interrogate the suspects simultaneously. The landlord's interview reveals a crush on the insurance agent, while Sang-ju's aversion to fire is uncovered, casting doubt on his involvement in the arson.
Jung-hyun's interrogation is tense, with the entitled young man lashing out and threatening legal action. His alibi of playing poker with friends during the time of the fire is shaky at best. Meanwhile, Hyo-joo's awakening brings a glimmer of hope, but her amnesia complicates the case further, leaving the detectives without a crucial witness.
Joong-ryeok's personal life is touched upon, with his daughters reminding him of the T-Rex figurine and his wife's entrepreneurial spirit. The next day, his search for the figurine in the hospital leads to a heartwarming encounter with a young boy, Dong-goo, who clutches the very item Joong-ryeok seeks.
Yu-bin's return to the crime scene is fruitless, and the team's briefing yields no new leads, leaving Mr. Yoon as the only suspect. Yu-bin's suspicion that Mr. Yoon knew about the fire is based on the man's odd behavior and the fact that he had paid off his insurance just months before the incident.
Joong-ryeok's defense of Mr. Yoon is met with Yu-bin's logical deductions, and the tension between them is palpable. Joong-ryeok's moment of clarity comes as he helps children rebuild their sand tower, a metaphor for the case that seems to be collapsing around them.
Tan-sik's discovery of a link between a food delivery app and the restaurants, and Min-seo's further investigation into the insurance angle, open new avenues of inquiry. However, Yu-bin's decision to remove Joong-ryeok from the case for his own good adds another layer of conflict to the team dynamic.
The episode concludes with Joong-ryeok receiving an anonymous tip about the fire case, a plot twist that promises to shake things up in the following episodes. As the team navigates the tangled web of lies, secrets, and motives, one thing is clear: the truth is never as straightforward as it seems, and the path to justice is fraught with obstacles.
"Denial" is a testament to the team's determination and the complexities of human nature. It keeps viewers on the edge of their seats, eager to see how the detectives will untangle the web of deceit and bring the perpetrator to light. With each episode, Seoul Busters continues to deliver a compelling mix of crime investigation and character-driven drama, proving itself as a standout series in the genre.