In the season finale of Seoul Busters, thedetectives of the team come together to unravel a complex web of murders and deceit, culminating in a dramatic confrontation and arrest that tests their limits. The episode opens with a tense bus ride where students discuss midterms, only for their conversation to be interrupted by a loud noise, signaling the start of the finale's high-stakes events.

As the investigation intensifies, Yubin makes a shocking revelation to the team: Han Junho, their primary suspect, is not the true culprit behind the murders. Despite the lack of concrete evidence, the team, driven by their trust in Yubin, agrees to pursue the case further. This decision sets the stage for a series of revelations that point to Prof. Sim as the mastermind behind the crimes.
The detectives, led by their unwavering commitment to justice, confront Prof. Sim in a scene filled with tension and fear. Prof. Sim's claims that the stabbing of Detective Jung was a business decision, not personal, only deepens the mystery and adds a chilling layer to his character. As the team digs deeper, they uncover discrepancies in the evidence, leading them to the realization that the killers of Jung Hyunjoo and Detective Jung might be the same person.
The investigation reaches a boiling point as the detectives scramble to gather DNA evidence to link Hyunwoo to the crime. Their search for a crucial piece of evidence that would hold Hyunwoo accountable leads to an intense and dangerous encounter with Prof. Sim. In a surprising twist, the team manages to subdue and capture Prof. Sim using pepper spray, a moment that marks a significant victory for the team.
With Prof. Sim in custody, the team reflects on their journey and the challenges they've overcome. Detective Jung's return to work after his recovery is a revitalizing force for the team, and they celebrate their success over a meal, teasing each other and planning for the future. The camaraderie among the detectives is palpable, and their unity is a testament to the strength of their team.
A year later, the team has evolved, with Yubin stepping up as a leader and embracing new challenges. The farewell party for Joongryeok is a bittersweet moment that highlights the team's camaraderie and the lasting bonds they've formed. As they share laughs and memories, they promise to stay connected, no matter where their careers take them.
The finale ends with Yubin leading a new case, a symbol of the team's resilience and their readiness to face whatever challenges lie ahead. United in their mission, the detectives of Seoul Busters are a force to be reckoned with, and the finale leaves viewers with an optimistic outlook for the future of the team and the justice they serve.