Watch Mouse S01e20 210519 720p-next 1 [Fresh • 2026]

He eventually visits Ba-reum’s unmarked grave, suggesting a complex form of closure and a sliver of forgiveness for the man who was both his partner and his enemy.

Ba-reum discovers that he is the biological son of the "Head Hunter," Han Seo-joon, and that his life was a meticulously controlled experiment by the OZ organization .

Watch the dramatic moment when Ba-reum's past finally catches up with him: Watch Mouse S01E20 210519 720p-NEXT 1

The series finale of the South Korean thriller Mouse (Episode 20), which aired on May 19, 2021, delivers a haunting conclusion to the "nature vs. nurture" debate that defined the series. This episode marks the final transformation of Jeong Ba-reum (Lee Seung-gi) from a cold-blooded predator into a man utterly consumed by the weight of his own conscience. The Ultimate Punishment: Empathy

In a moving final sequence, a dying Ba-reum has a vision of himself as a young boy (Jae-hoon) in a church. He tells his younger self that he is "no longer a monster," finally finding a small measure of spiritual peace before passing away. Legacy of the "Mouse" Experiment nurture" debate that defined the series

Although she cannot forgive Ba-reum for killing her grandmother, she chooses to live her life as a survivor rather than a victim.

In a twist of poetic justice, the very brain surgery intended to save Ba-reum's life becomes his greatest torment. By transplanting parts of the empathetic Sung Yo-han's brain into his own, Ba-reum is forced to feel the visceral pain and guilt of his previous murders. He tells his younger self that he is

The episode also resolves the fates of the supporting cast and the societal impact of the OZ organization's actions: